Virtualize GL matrix operations and use a client-side matrix when GL is indirect

This is useful because sometimes we need to get the current matrix, which
is too expensive when indirect rendering.

In addition, this virtualization makes it easier to clean up the API in
the future.

cogl-matrix.h

@@ -151,6 +151,27 @@ void cogl_matrix_scale (CoglMatrix *matrix,
 			float sy,
 			float sz);
 
+/**
+ * cogl_matrix_frustum:
+ * @matrix: A 4x4 transformation matrix
+ * @left: coord of left vertical clipping plane
+ * @right: coord of right vertical clipping plane
+ * @bottom: coord of bottom horizontal clipping plane
+ * @top: coord of top horizontal clipping plane
+ * @near: positive distance to near depth clipping plane
+ * @far: positive distance to far depth clipping plane
+ *
+ * Multiplies the matrix by the given frustum perspective matrix.
+ *
+ */
+void cogl_matrix_frustum (CoglMatrix *matrix,
+                          float       left,
+                          float       right,
+                          float       bottom,
+                          float       top,
+                          float       z_near,
+                          float       z_far);
+
 /**
  * cogl_matrix_transform_point:
  * @matrix: A 4x4 transformation matrix

cogl.h.in

@@ -563,6 +563,24 @@ void            cogl_clip_stack_save          (void);
  */
 void            cogl_clip_stack_restore       (void);
 
+/**
+ * cogl_flush_gl_state:
+ * @flags: flags controlling what is flushed; currently unused, pass in 0
+ *
+ * As an optimization, COGL functions may not immediately modify GL's
+ * state, instead batching up changes and applying them "just in
+ * time."  Unapplied state could include glEnable() flags and the
+ * current transformation matrix among other examples. If you want to
+ * use GL directly, you need to flush any state COGL may have kept
+ * around. cogl_flush_gl_state() syncs all of COGL's state to GL.
+ *
+ * Since: 1.0
+ */
+void            cogl_flush_gl_state         (int      flags);
+
+/* private */
+void            _cogl_set_indirect_context  (gboolean indirect);
+
 G_END_DECLS
 
 #undef __COGL_H_INSIDE__

common/Makefile.am

@@ -24,6 +24,8 @@ libclutter_cogl_common_la_SOURCES = 	\
 	cogl-bitmap.h 			\
 	cogl-bitmap.c 			\
 	cogl-bitmap-fallback.c 		\
+	cogl-current-matrix.c		\
+	cogl-current-matrix.h		\
 	cogl-primitives.h 		\
 	cogl-primitives.c 		\
 	cogl-bitmap-pixbuf.c 		\
@@ -34,6 +36,8 @@ libclutter_cogl_common_la_SOURCES = 	\
 	cogl-vertex-buffer-private.h 	\
 	cogl-vertex-buffer.c		\
 	cogl-matrix.c			\
+	cogl-matrix-stack.c		\
+	cogl-matrix-stack.h		\
 	cogl-material.c			\
 	cogl-material-private.h		\
 	cogl-debug.c

common/cogl-current-matrix.c

@@ -0,0 +1,452 @@
+/*
+ * Clutter COGL
+ *
+ * A basic GL/GLES Abstraction/Utility Layer
+ *
+ * Authored By Havoc Pennington <hp@pobox.com> for litl
+ *
+ * Copyright (C) 2009 OpenedHand
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "cogl.h"
+#include "cogl-context.h"
+#include "cogl-internal.h"
+#include "cogl-current-matrix.h"
+#include "cogl-matrix-stack.h"
+
+#include <string.h>
+#include <math.h>
+
+void
+_cogl_set_current_matrix (CoglMatrixMode mode)
+{
+  GLenum gl_mode;
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  if (mode == ctx->matrix_mode)
+    return;
+  ctx->matrix_mode = mode;
+
+  gl_mode = 0; /* silence compiler warning */
+  switch (mode)
+    {
+    case COGL_MATRIX_MODELVIEW:
+      gl_mode = GL_MODELVIEW;
+      break;
+    case COGL_MATRIX_PROJECTION:
+      gl_mode = GL_PROJECTION;
+      break;
+    case COGL_MATRIX_TEXTURE:
+      gl_mode = GL_TEXTURE;
+      break;
+    }
+
+  GE (glMatrixMode (gl_mode));
+}
+
+static void
+_cogl_get_client_stack (CoglContext      *ctx,
+                        CoglMatrixStack **current_stack_p)
+{
+  if (ctx->modelview_stack &&
+      ctx->matrix_mode == COGL_MATRIX_MODELVIEW)
+    *current_stack_p  = ctx->modelview_stack;
+  else
+    *current_stack_p = NULL;
+}
+
+#define _COGL_GET_CONTEXT_AND_STACK(contextvar, stackvar, rval) \
+  CoglMatrixStack *stackvar;                                    \
+  _COGL_GET_CONTEXT (contextvar, rval);                         \
+  _cogl_get_client_stack (contextvar, &stackvar)
+
+void
+_cogl_current_matrix_push (void)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_push (current_stack);
+  else
+    GE (glPushMatrix ());
+}
+
+void
+_cogl_current_matrix_pop (void)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_pop (current_stack);
+  else
+    GE (glPopMatrix ());
+}
+
+void
+_cogl_current_matrix_identity (void)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_load_identity (current_stack);
+  else
+    GE (glLoadIdentity ());
+}
+
+void
+_cogl_current_matrix_load (const CoglMatrix *matrix)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_set (current_stack, matrix);
+  else
+    GE (glLoadMatrixf (cogl_matrix_get_array (matrix)));
+}
+
+void
+_cogl_current_matrix_multiply (const CoglMatrix *matrix)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_multiply (current_stack, matrix);
+  else
+    GE (glMultMatrixf (cogl_matrix_get_array (matrix)));
+}
+
+void
+_cogl_current_matrix_rotate (float angle,
+                             float x,
+                             float y,
+                             float z)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_rotate (current_stack, angle, x, y, z);
+  else
+    GE (glRotatef (angle, x, y, z));
+}
+
+void
+_cogl_current_matrix_scale (float x,
+                            float y,
+                            float z)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_scale (current_stack, x, y, z);
+  else
+    GE (glScalef (x, y, z));
+}
+
+void
+_cogl_current_matrix_translate (float x,
+                                float y,
+                                float z)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_translate (current_stack, x, y, z);
+  else
+    GE (glTranslatef (x, y, z));
+}
+
+void
+_cogl_current_matrix_frustum (float left,
+                              float right,
+                              float bottom,
+                              float top,
+                              float near_val,
+                              float far_val)
+{
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_frustum (current_stack,
+                                left, right,
+                                top, bottom,
+                                near_val,
+                                far_val);
+  else
+    GE (glFrustum (left, right, bottom, top, near_val, far_val));
+}
+
+void
+_cogl_current_matrix_ortho (float             left,
+                            float             right,
+                            float             bottom,
+                            float             top,
+                            float             near_val,
+                            float             far_val)
+{
+#if 0
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+
+  if (current_stack != NULL)
+    _cogl_matrix_stack_ortho (current_stack,
+                              left, right,
+                              top, bottom,
+                              near_val,
+                              far_val);
+  else
+    GE (glOrtho (left, right, bottom, top, near_val, far_val));
+#else
+  /* Nobody is using glOrtho right now anyway, so not bothering */
+  g_warning ("%s not implemented, need to code cogl_matrix_ortho() if you need this function",
+             G_STRFUNC);
+#endif
+}
+
+void
+_cogl_get_matrix (CoglMatrixMode mode,
+                  CoglMatrix    *matrix)
+{
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  if (ctx->modelview_stack != NULL &&
+      mode == COGL_MATRIX_MODELVIEW)
+    {
+      _cogl_matrix_stack_get (ctx->modelview_stack, matrix);
+    }
+  else
+    {
+      GLenum gl_mode;
+
+      gl_mode = 0; /* silence compiler warning */
+      switch (mode)
+        {
+        case COGL_MATRIX_MODELVIEW:
+          gl_mode = GL_MODELVIEW_MATRIX;
+          break;
+        case COGL_MATRIX_PROJECTION:
+          gl_mode = GL_PROJECTION_MATRIX;
+          break;
+        case COGL_MATRIX_TEXTURE:
+          gl_mode = GL_TEXTURE_MATRIX;
+          break;
+        }
+
+      /* hack alert: CoglMatrix is not really expecting us to
+       * get *mutable* floats array from it
+       */
+      GE (glGetFloatv (gl_mode, (GLfloat*) matrix));
+    }
+}
+
+void
+_cogl_current_matrix_state_init (void)
+{
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  ctx->matrix_mode = COGL_MATRIX_MODELVIEW;
+  ctx->modelview_stack = NULL;
+
+  if (ctx->indirect)
+    {
+      ctx->modelview_stack =
+        _cogl_matrix_stack_new ();
+    }
+}
+
+void
+_cogl_current_matrix_state_destroy (void)
+{
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  if (ctx->modelview_stack)
+    _cogl_matrix_stack_destroy (ctx->modelview_stack);
+}
+
+void
+_cogl_current_matrix_state_flush (void)
+{
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  if (ctx->matrix_mode != COGL_MATRIX_MODELVIEW)
+    {
+      g_warning ("matrix state must be flushed in MODELVIEW mode");
+      return;
+    }
+
+  if (ctx->modelview_stack)
+    {
+      _cogl_matrix_stack_flush_to_gl (ctx->modelview_stack,
+                                      GL_MODELVIEW);
+    }
+}
+
+void
+cogl_push_matrix (void)
+{
+  _cogl_current_matrix_push ();
+}
+
+void
+cogl_pop_matrix (void)
+{
+  _cogl_current_matrix_pop ();
+}
+
+void
+cogl_scale (float x, float y, float z)
+{
+  _cogl_current_matrix_scale (x, y, z);
+}
+
+void
+cogl_translate (float x, float y, float z)
+{
+  _cogl_current_matrix_translate (x, y, z);
+}
+
+void
+cogl_rotate (float angle, float x, float y, float z)
+{
+  _cogl_current_matrix_rotate (angle, x, y, z);
+}
+
+void
+_cogl_set_matrix (const CoglMatrix *matrix)
+{
+  _cogl_current_matrix_load (matrix);
+}
+
+void
+cogl_get_modelview_matrix (CoglMatrix *matrix)
+{
+  _cogl_get_matrix (COGL_MATRIX_MODELVIEW,
+                    matrix);
+}
+
+void
+cogl_get_projection_matrix (CoglMatrix *matrix)
+{
+  _cogl_get_matrix (COGL_MATRIX_PROJECTION,
+                    matrix);
+}
+
+void
+cogl_perspective (float fovy,
+		  float aspect,
+		  float zNear,
+		  float zFar)
+{
+  float xmax, ymax;
+  float x, y, c, d;
+  float fovy_rad_half = (fovy * G_PI) / 360;
+  CoglMatrix perspective;
+  GLfloat m[16];
+
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  memset (&m[0], 0, sizeof (m));
+
+  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
+  _cogl_current_matrix_identity ();
+
+  /*
+   * Based on the original algorithm in perspective():
+   *
+   * 1) xmin = -xmax => xmax + xmin == 0 && xmax - xmin == 2 * xmax
+   * same true for y, hence: a == 0 && b == 0;
+   *
+   * 2) When working with small numbers, we are loosing significant
+   * precision
+   */
+  ymax = (zNear * (sinf (fovy_rad_half) / cosf (fovy_rad_half)));
+  xmax = (ymax * aspect);
+
+  x = (zNear / xmax);
+  y = (zNear / ymax);
+  c = (-(zFar + zNear) / ( zFar - zNear));
+  d = (-(2 * zFar) * zNear) / (zFar - zNear);
+
+#define M(row,col)  m[col*4+row]
+  M(0,0) = x;
+  M(1,1) = y;
+  M(2,2) = c;
+  M(2,3) = d;
+  M(3,2) = -1.0;
+
+  cogl_matrix_init_from_array (&perspective, m);
+  _cogl_current_matrix_multiply (&perspective);
+
+  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+
+  /* Calculate and store the inverse of the matrix */
+  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
+
+#define m ctx->inverse_projection
+  M(0, 0) = (1.0 / x);
+  M(1, 1) = (1.0 / y);
+  M(2, 3) = -1.0;
+  M(3, 2) = (1.0 / d);
+  M(3, 3) = (c / d);
+#undef m
+
+#undef M
+}
+
+void
+cogl_frustum (float        left,
+	      float        right,
+	      float        bottom,
+	      float        top,
+	      float        z_near,
+	      float        z_far)
+{
+  float c, d;
+
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
+  _cogl_current_matrix_identity ();
+
+  _cogl_current_matrix_frustum (left,
+                                right,
+                                bottom,
+                                top,
+                                z_near,
+                                z_far);
+
+  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+
+  /* Calculate and store the inverse of the matrix */
+  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
+
+  c = - (z_far + z_near) /  (z_far - z_near);
+  d = - (2 * (z_far * z_near)) /  (z_far - z_near);
+
+#define M(row,col)  ctx->inverse_projection[col*4+row]
+  M(0,0) =  (right - left) /  (2 * z_near);
+  M(0,3) =  (right + left) /  (2 * z_near);
+  M(1,1) =  (top - bottom) /  (2 * z_near);
+  M(1,3) =  (top + bottom) /  (2 * z_near);
+  M(2,3) = -1.0;
+  M(3,2) = 1.0 / d;
+  M(3,3) = c / d;
+#undef M
+}

common/cogl-current-matrix.h

@@ -0,0 +1,91 @@
+/*
+ * Clutter COGL
+ *
+ * A basic GL/GLES Abstraction/Utility Layer
+ *
+ * Authored By Havoc Pennington <hp@pobox.com> for litl
+ *
+ * Copyright (C) 2009 OpenedHand
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __COGL_CURRENT_MATRIX_H
+#define __COGL_CURRENT_MATRIX_H
+
+#include <cogl/cogl-matrix.h>
+
+/**
+ * CoglMatrixMode:
+ * @COGL_MATRIX_MODELVIEW: Select model-view matrix stack
+ * @COGL_MATRIX_PROJECTION: Select projection matrix stack
+ * @COGL_MATRIX_TEXTURE: Select texture matrix stack
+ *
+ * There are several matrix stacks affected by the COGL current matrix
+ * operations (which are private). Code should always leave the
+ * model-view matrix active, switching to the projection matrix stack
+ * only temporarily in order to modify the projection matrix. Most
+ * COGL and Clutter APIs (other than the current matrix operations)
+ * will assume the model-view matrix is active when the API is
+ * invoked.
+ *
+ * Since: 1.0
+ */
+typedef enum
+{
+  COGL_MATRIX_MODELVIEW   = 1,
+  COGL_MATRIX_PROJECTION  = 2,
+  COGL_MATRIX_TEXTURE  = 3
+} CoglMatrixMode;
+
+#define COGL_TYPE_MATRIX_MODE     (cogl_matrix_mode_get_type ())
+GType cogl_matrix_mode_get_type (void) G_GNUC_CONST;
+
+void _cogl_set_current_matrix            (CoglMatrixMode    mode);
+void _cogl_current_matrix_push           (void);
+void _cogl_current_matrix_pop            (void);
+void _cogl_current_matrix_identity       (void);
+void _cogl_current_matrix_load           (const CoglMatrix *matrix);
+void _cogl_current_matrix_multiply       (const CoglMatrix *matrix);
+void _cogl_current_matrix_rotate         (float             angle,
+                                          float             x,
+                                          float             y,
+                                          float             z);
+void _cogl_current_matrix_scale          (float             x,
+                                          float             y,
+                                          float             z);
+void _cogl_current_matrix_translate      (float             x,
+                                          float             y,
+                                          float             z);
+void _cogl_current_matrix_frustum        (float             left,
+                                          float             right,
+                                          float             bottom,
+                                          float             top,
+                                          float             near_val,
+                                          float             far_val);
+void _cogl_current_matrix_ortho          (float             left,
+                                          float             right,
+                                          float             bottom,
+                                          float             top,
+                                          float             near_val,
+                                          float             far_val);
+void _cogl_get_matrix                    (CoglMatrixMode    mode,
+                                          CoglMatrix       *matrix);
+void _cogl_current_matrix_state_init     (void);
+void _cogl_current_matrix_state_destroy  (void);
+void _cogl_current_matrix_state_flush    (void);
+
+#endif /* __COGL_CURRENT_MATRIX_H */

common/cogl-material.c

@@ -821,9 +821,9 @@ _cogl_material_layer_flush_gl_sampler_state (CoglMaterialLayer  *layer,
        layer->flags & COGL_MATERIAL_LAYER_FLAG_HAS_USER_MATRIX))
 #endif
     {
-      GE (glMatrixMode (GL_TEXTURE));
+      _cogl_set_current_matrix (COGL_MATRIX_TEXTURE);
-      GE (glLoadMatrixf ((GLfloat *)&layer->matrix));
+      _cogl_current_matrix_load (&layer->matrix);
-      GE (glMatrixMode (GL_MODELVIEW));
+      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
     }
 }
 

common/cogl-matrix-stack.c

@@ -0,0 +1,327 @@
+/*
+ * Clutter COGL
+ *
+ * A basic GL/GLES Abstraction/Utility Layer
+ *
+ * Authored By Havoc Pennington <hp@pobox.com> for litl
+ *
+ * Copyright (C) 2009 OpenedHand
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "cogl.h"
+#include "cogl-context.h"
+#include "cogl-internal.h"
+#include "cogl-matrix-stack.h"
+
+typedef struct {
+  CoglMatrix matrix;
+  /* count of pushes with no changes; when a change is
+   * requested, we create a new state and decrement this
+   */
+  int push_count;
+} CoglMatrixState;
+
+/**
+ * CoglMatrixStack:
+ *
+ * Stores a cogl-side matrix stack, which we use as a cache
+ * so we can get the matrix efficiently when using indirect
+ * rendering.
+ */
+struct _CoglMatrixStack
+{
+  GSList *stack;
+
+  /* which state does GL have, NULL if unknown */
+  CoglMatrixState *flushed_state;
+};
+
+
+static CoglMatrixState*
+_cogl_matrix_state_new (void)
+{
+  CoglMatrixState *state;
+
+  state = g_slice_new0 (CoglMatrixState);
+
+  /* load identity */
+  cogl_matrix_init_identity (&state->matrix);
+
+  /* state->push_count defaults to 0 */
+
+  return state;
+}
+
+static void
+_cogl_matrix_state_destroy (CoglMatrixState *state)
+{
+
+  g_slice_free (CoglMatrixState, state);
+}
+
+static CoglMatrixState*
+_cogl_matrix_stack_top (CoglMatrixStack *stack)
+{
+  return stack->stack->data;
+}
+
+static CoglMatrixState*
+_cogl_matrix_stack_top_mutable (CoglMatrixStack *stack)
+{
+  CoglMatrixState *state;
+  CoglMatrixState *new_top;
+
+  state = _cogl_matrix_stack_top (stack);
+
+  if (state->push_count == 0)
+    return state;
+
+  state->push_count -= 1;
+
+  new_top = _cogl_matrix_state_new ();
+
+  new_top->matrix = state->matrix;
+
+  if (stack->flushed_state == state)
+    {
+      stack->flushed_state = new_top;
+    }
+
+  stack->stack =
+    g_slist_prepend (stack->stack,
+                     new_top);
+
+  return new_top;
+}
+
+CoglMatrixStack*
+_cogl_matrix_stack_new (void)
+{
+  CoglMatrixStack *stack;
+  CoglMatrixState *state;
+
+  stack = g_slice_new0 (CoglMatrixStack);
+  state = _cogl_matrix_state_new ();
+  stack->stack =
+    g_slist_prepend (stack->stack,
+                     state);
+
+  return stack;
+}
+
+void
+_cogl_matrix_stack_destroy (CoglMatrixStack *stack)
+{
+  while (stack->stack)
+    {
+      CoglMatrixState *state;
+
+      state = stack->stack->data;
+      _cogl_matrix_state_destroy (state);
+      stack->stack =
+        g_slist_delete_link (stack->stack,
+                             stack->stack);
+    }
+
+  g_slice_free (CoglMatrixStack, stack);
+}
+
+void
+_cogl_matrix_stack_push (CoglMatrixStack *stack)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top (stack);
+
+  /* we lazily create a new stack top if someone changes the matrix
+   * while push_count > 0
+   */
+  state->push_count += 1;
+}
+
+void
+_cogl_matrix_stack_pop (CoglMatrixStack *stack)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top (stack);
+
+  if (state->push_count > 0)
+    {
+      state->push_count -= 1;
+    }
+  else
+    {
+      if (stack->stack->next == NULL)
+        {
+          g_warning ("Too many matrix pops");
+          return;
+        }
+
+      if (stack->flushed_state == state)
+        {
+          stack->flushed_state = NULL;
+        }
+
+      stack->stack =
+        g_slist_delete_link (stack->stack,
+                             stack->stack);
+      _cogl_matrix_state_destroy (state);
+    }
+}
+
+void
+_cogl_matrix_stack_load_identity (CoglMatrixStack *stack)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_init_identity (&state->matrix);
+
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_scale (CoglMatrixStack *stack,
+                          float            x,
+                          float            y,
+                          float            z)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_scale (&state->matrix, x, y, z);
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_translate (CoglMatrixStack *stack,
+                              float            x,
+                              float            y,
+                              float            z)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_translate (&state->matrix, x, y, z);
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_rotate (CoglMatrixStack *stack,
+                           float            angle,
+                           float            x,
+                           float            y,
+                           float            z)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_rotate (&state->matrix, angle, x, y, z);
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_multiply (CoglMatrixStack  *stack,
+                             const CoglMatrix *matrix)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_multiply (&state->matrix, &state->matrix, matrix);
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_get (CoglMatrixStack *stack,
+                        CoglMatrix      *matrix)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top (stack);
+
+  *matrix = state->matrix;
+}
+
+void
+_cogl_matrix_stack_set (CoglMatrixStack  *stack,
+                        const CoglMatrix *matrix)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  state->matrix = *matrix;
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_frustum (CoglMatrixStack *stack,
+                            float            left,
+                            float            right,
+                            float            bottom,
+                            float            top,
+                            float            z_near,
+                            float            z_far)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top_mutable (stack);
+  cogl_matrix_frustum (&state->matrix,
+                       left, right, bottom, top,
+                       z_near, z_far);
+  /* mark dirty */
+  stack->flushed_state = NULL;
+}
+
+void
+_cogl_matrix_stack_flush_to_gl (CoglMatrixStack *stack,
+                                GLenum           gl_mode)
+{
+  CoglMatrixState *state;
+
+  state = _cogl_matrix_stack_top (stack);
+
+  if (stack->flushed_state == state)
+    return;
+
+  /* NOTE we assume caller was in MODELVIEW mode */
+
+  if (gl_mode != GL_MODELVIEW)
+    GE (glMatrixMode (gl_mode));
+
+  /* In theory it might help the GL implementation if we used our
+   * local analysis of the matrix and called Translate/Scale rather
+   * than LoadMatrix to send a 2D matrix
+   */
+
+  GE (glLoadMatrixf (cogl_matrix_get_array (&state->matrix)));
+  stack->flushed_state = state;
+
+  if (gl_mode != GL_MODELVIEW)
+    GE (glMatrixMode (GL_MODELVIEW));
+}

common/cogl-matrix-stack.h

@@ -0,0 +1,67 @@
+/*
+ * Clutter COGL
+ *
+ * A basic GL/GLES Abstraction/Utility Layer
+ *
+ * Authored By Havoc Pennington <hp@pobox.com> for litl
+ *
+ * Copyright (C) 2009 OpenedHand
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __COGL_MATRIX_STACK_H
+#define __COGL_MATRIX_STACK_H
+
+#include <cogl/cogl-matrix.h>
+
+typedef struct _CoglMatrixStack CoglMatrixStack;
+
+CoglMatrixStack* _cogl_matrix_stack_new           (void);
+void             _cogl_matrix_stack_destroy       (CoglMatrixStack  *stack);
+void             _cogl_matrix_stack_push          (CoglMatrixStack  *stack);
+void             _cogl_matrix_stack_pop           (CoglMatrixStack  *stack);
+void             _cogl_matrix_stack_load_identity (CoglMatrixStack  *stack);
+void             _cogl_matrix_stack_scale         (CoglMatrixStack  *stack,
+                                                   float             x,
+                                                   float             y,
+                                                   float             z);
+void             _cogl_matrix_stack_translate     (CoglMatrixStack  *stack,
+                                                   float             x,
+                                                   float             y,
+                                                   float             z);
+void             _cogl_matrix_stack_rotate        (CoglMatrixStack  *stack,
+                                                   float             angle,
+                                                   float             x,
+                                                   float             y,
+                                                   float             z);
+void             _cogl_matrix_stack_multiply      (CoglMatrixStack  *stack,
+                                                   const CoglMatrix *matrix);
+void             _cogl_matrix_stack_get           (CoglMatrixStack  *stack,
+                                                   CoglMatrix       *matrix);
+void             _cogl_matrix_stack_set           (CoglMatrixStack  *stack,
+                                                   const CoglMatrix *matrix);
+void             _cogl_matrix_stack_frustum       (CoglMatrixStack  *stack,
+                                                   float             left,
+                                                   float             right,
+                                                   float             bottom,
+                                                   float             top,
+                                                   float             z_near,
+                                                   float             z_far);
+void             _cogl_matrix_stack_flush_to_gl   (CoglMatrixStack  *stack,
+                                                   GLenum            gl_mode);
+
+#endif /* __COGL_MATRIX_STACK_H */

common/cogl-matrix.c

@@ -140,6 +140,48 @@ cogl_matrix_transform_point (const CoglMatrix *matrix,
   *w = matrix->wx * _x + matrix->wy * _y + matrix->wz * _z + matrix->ww * _w;
 }
 
+void
+cogl_matrix_frustum (CoglMatrix *matrix,
+                     float       left,
+                     float       right,
+                     float       bottom,
+                     float       top,
+                     float       z_near,
+                     float       z_far)
+{
+  float x, y, a, b, c, d;
+  CoglMatrix frustum;
+
+  x = (2.0f * z_near) / (right - left);
+  y = (2.0f * z_near) / (top - bottom);
+  a = (right + left) / (right - left);
+  b = (top + bottom) / (top - bottom);
+  c = -(z_far + z_near) / ( z_far - z_near);
+  d = -(2.0f * z_far* z_near) / (z_far - z_near);
+
+  frustum.xx = x;
+  frustum.yx = 0.0f;
+  frustum.zx = 0.0f;
+  frustum.wx = 0.0f;
+
+  frustum.xy = 0.0f;
+  frustum.yy = y;
+  frustum.zy = 0.0f;
+  frustum.wy = 0.0f;
+
+  frustum.xz = a;
+  frustum.yz = b;
+  frustum.zz = c;
+  frustum.wz = -1.0f;
+
+  frustum.xw = 0.0f;
+  frustum.yw = 0.0f;
+  frustum.zw = d;
+  frustum.ww = 0.0f;
+
+  cogl_matrix_multiply (matrix, matrix, &frustum);
+}
+
 void
 cogl_matrix_init_from_array (CoglMatrix *matrix, const float *array)
 {

common/cogl-util.c

@@ -35,6 +35,7 @@
 #include "cogl-fixed.h"
 #include "cogl-internal.h"
 #include "cogl-material.h"
+#include "cogl-current-matrix.h"
 #include "cogl-offscreen.h"
 #include "cogl-shader.h"
 #include "cogl-texture.h"
@@ -208,6 +209,28 @@ cogl_buffer_target_get_type (void)
   return gtype;
 }
 
+GType
+cogl_matrix_mode_get_type (void)
+{
+  static GType gtype = 0;
+
+  if (G_UNLIKELY (gtype == 0))
+    {
+      static const GEnumValue values[] = {
+        { COGL_MATRIX_MODELVIEW, "COGL_MATRIX_MODELVIEW", "modelview" },
+        { COGL_MATRIX_PROJECTION, "COGL_MATRIX_PROJECTION", "projection" },
+        { COGL_MATRIX_TEXTURE, "COGL_MATRIX_TEXTURE", "texture" },
+        { 0, NULL, NULL }
+      };
+
+      gtype =
+        g_enum_register_static (g_intern_static_string ("CoglMatrixMode"),
+                                values);
+    }
+
+  return gtype;
+}
+
 GType
 cogl_texture_flags_get_type (void)
 {

common/cogl-vertex-buffer.c

@@ -1621,6 +1621,8 @@ cogl_vertex_buffer_draw (CoglHandle handle,
 
   enable_state_for_drawing_buffer (buffer);
 
+  _cogl_current_matrix_state_flush ();
+
   /* FIXME: flush cogl cache */
   GE (glDrawArrays (mode, first, count));
 
@@ -1647,6 +1649,8 @@ cogl_vertex_buffer_draw_elements (CoglHandle handle,
 
   enable_state_for_drawing_buffer (buffer);
 
+  _cogl_current_matrix_state_flush ();
+
   /* FIXME: flush cogl cache */
   GE (glDrawRangeElements (mode, min_index, max_index,
                            count, indices_type, indices));

gl/cogl-context.c

@@ -37,6 +37,7 @@
 #include <string.h>
 
 static CoglContext *_context = NULL;
+static gboolean gl_is_indirect = FALSE;
 
 gboolean
 cogl_create_context ()
@@ -59,6 +60,8 @@ cogl_create_context ()
 
   _context->enable_backface_culling = FALSE;
 
+  _context->indirect = gl_is_indirect;
+
   _context->material_handles = NULL;
   _context->material_layer_handles = NULL;
   _context->default_material = cogl_material_new ();
@@ -143,6 +146,9 @@ cogl_create_context ()
   /* Initialise the clip stack */
   _cogl_clip_stack_state_init ();
 
+  /* Initialise matrix stack */
+  _cogl_current_matrix_state_init ();
+
   /* Create default textures used for fall backs */
   _context->default_gl_texture_2d_tex =
     cogl_texture_new_from_data (1, /* width */
@@ -182,6 +188,8 @@ cogl_destroy_context ()
 
   _cogl_clip_stack_state_destroy ();
 
+  _cogl_current_matrix_state_destroy ();
+
   if (_context->path_nodes)
     g_array_free (_context->path_nodes, TRUE);
 
@@ -226,3 +234,32 @@ _cogl_context_get_default ()
 
   return _context;
 }
+
+/**
+ * _cogl_set_indirect_context:
+ * @indirect: TRUE if GL context is indirect
+ *
+ * Advises COGL that the GL context is indirect (commands are sent
+ * over a socket). COGL uses this information to try to avoid
+ * round-trips in its use of GL, for example.
+ *
+ * This function cannot be called "on the fly," only before COGL
+ * initializes.
+ */
+void
+_cogl_set_indirect_context (gboolean indirect)
+{
+  /* we get called multiple times if someone creates
+   * more than the default stage
+   */
+  if (_context != NULL)
+    {
+      if (indirect != _context->indirect)
+        g_warning ("Right now all stages will be treated as "
+                   "either direct or indirect, ignoring attempt "
+                   "to change to indirect=%d", indirect);
+      return;
+    }
+
+  gl_is_indirect = indirect;
+}

gl/cogl-context.h

@@ -28,6 +28,8 @@
 
 #include "cogl-primitives.h"
 #include "cogl-clip-stack.h"
+#include "cogl-matrix-stack.h"
+#include "cogl-current-matrix.h"
 
 typedef struct
 {
@@ -48,6 +50,12 @@ typedef struct
 
   gboolean          enable_backface_culling;
 
+  gboolean          indirect;
+
+  /* Client-side matrix stack or NULL if none */
+  CoglMatrixMode    matrix_mode;
+  CoglMatrixStack  *modelview_stack;
+
   /* Cache of inverse projection matrix */
   float            inverse_projection[16];
 

gl/cogl-fbo.c

@@ -265,29 +265,29 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
              from a non-screen buffer */
 	  GE( glPushAttrib (GL_VIEWPORT_BIT) );
 
-	  GE( glMatrixMode (GL_PROJECTION) );
+          _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glPushMatrix () );
+          _cogl_current_matrix_push ();
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+          _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glPushMatrix () );
+          _cogl_current_matrix_push ();
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 	}
       else
 	{
 	  /* Override viewport and matrix setup if redirecting
              from another offscreen buffer */
-	  GE( glMatrixMode (GL_PROJECTION) );
+          _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+          _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 	}
       
       /* Setup new viewport and matrices */
       GE( glViewport (0, 0, fbo->width, fbo->height) );
-      GE( glTranslatef (-1.0f, -1.0f, 0.0f) );
+      _cogl_current_matrix_translate (-1.0f, -1.0f, 0.0f);
-      GE( glScalef (2.0f / fbo->width, 2.0f / fbo->height, 1.0f) );
+      _cogl_current_matrix_scale (2.0f / fbo->width, 2.0f / fbo->height, 1.0f);
       
       /* Bind offscreen framebuffer object */
       GE( glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, fbo->gl_handle) );
@@ -314,11 +314,11 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
              from an offscreen buffer */
 	  GE( glPopAttrib () );
 
-	  GE( glMatrixMode (GL_PROJECTION) );
+          _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glPopMatrix () );
+          _cogl_current_matrix_pop ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+          _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glPopMatrix () );
+          _cogl_current_matrix_pop ();
 	}
       
       /* Bind window framebuffer object */

gl/cogl-primitives.c

@@ -87,6 +87,7 @@ _cogl_path_stroke_nodes ()
                                 COGL_MATERIAL_FLUSH_DISABLE_MASK,
                                 (guint32)~0, /* disable all texture layers */
                                 NULL);
+  _cogl_current_matrix_state_flush ();
 
   while (path_start < ctx->path_nodes->len)
     {
@@ -161,6 +162,7 @@ _cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
   GE( glColorMask (FALSE, FALSE, FALSE, FALSE) );
   GE( glDepthMask (FALSE) );
 
+  _cogl_current_matrix_state_flush ();
   while (path_start < path_size)
     {
       GE( glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
@@ -196,16 +198,18 @@ _cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
       GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
       /* Decrement all of the bits twice so that only pixels where the
          value is 3 will remain */
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
-      GE( glMatrixMode (GL_PROJECTION) );
+
-      GE( glPushMatrix () );
+      _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_push ();
+      _cogl_current_matrix_identity ();
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
-      GE( glMatrixMode (GL_MODELVIEW) );
+
-      GE( glPopMatrix () );
+      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+      _cogl_current_matrix_pop ();
     }
 
   GE( glStencilMask (~(GLuint) 0) );

gl/cogl-texture.c

@@ -2056,7 +2056,7 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
   cogl_enable (enable_flags);
 
   GE (glVertexPointer (2, GL_FLOAT, stride, vertex_pointer));
-
+  _cogl_current_matrix_state_flush ();
   GE (glDrawRangeElements (GL_TRIANGLES,
                            0, ctx->static_indices->len - 1,
                            6 * batch_len,
@@ -2085,6 +2085,7 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
                                       color == 2 ? 0xff : 0x00,
                                       0xff);
           cogl_material_flush_gl_state (outline, NULL);
+          _cogl_current_matrix_state_flush ();
           GE( glDrawArrays (GL_LINE_LOOP, 4 * i, 4) );
         }
     }
@@ -2896,6 +2897,7 @@ _cogl_texture_sliced_polygon (CoglTextureVertex *vertices,
                                         COGL_MATERIAL_FLUSH_LAYER0_OVERRIDE,
                                         gl_handle,
                                         NULL);
+          _cogl_current_matrix_state_flush ();
 
 	  GE( glDrawArrays (GL_TRIANGLE_FAN, 0, n_vertices) );
 	}
@@ -2986,6 +2988,7 @@ _cogl_multitexture_unsliced_polygon (CoglTextureVertex *vertices,
                                 COGL_MATERIAL_FLUSH_FALLBACK_MASK,
                                 fallback_mask,
                                 NULL);
+  _cogl_current_matrix_state_flush ();
 
   GE (glDrawArrays (GL_TRIANGLE_FAN, 0, n_vertices));
 }

gl/cogl.c

@@ -201,37 +201,6 @@ cogl_clear (const CoglColor *color)
    */
 }
 
-/* FIXME: inline most of these  */
-void
-cogl_push_matrix (void)
-{
-  GE( glPushMatrix() );
-}
-
-void
-cogl_pop_matrix (void)
-{
-  GE( glPopMatrix() );
-}
-
-void
-cogl_scale (float x, float y, float z)
-{
-  GE( glScalef (x, y, z) );
-}
-
-void
-cogl_translate (float x, float y, float z)
-{
-  GE( glTranslatef (x, y, z) );
-}
-
-void
-cogl_rotate (float angle, float x, float y, float z)
-{
-  GE( glRotatef (angle, x, y, z) );
-}
-
 static inline gboolean
 cogl_toggle_flag (CoglContext *ctx,
 		  gulong new_flags,
@@ -396,6 +365,7 @@ set_clip_plane (GLint plane_num,
   GLdouble plane[4];
 #endif
   GLfloat angle;
+  CoglMatrix inverse_projection;
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
   /* Calculate the angle between the axes and the line crossing the
@@ -403,18 +373,20 @@ set_clip_plane (GLint plane_num,
   angle = atan2f (vertex_b[1] - vertex_a[1],
                   vertex_b[0] - vertex_a[0]) * (180.0/G_PI);
 
-  GE( glPushMatrix () );
+  _cogl_current_matrix_push ();
   /* Load the identity matrix and multiply by the reverse of the
      projection matrix so we can specify the plane in screen
      coordinates */
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
-  GE( glMultMatrixf ((GLfloat *) ctx->inverse_projection) );
+  cogl_matrix_init_from_array (&inverse_projection,
+                               ctx->inverse_projection);
+  _cogl_current_matrix_multiply (&inverse_projection);
   /* Rotate about point a */
-  GE( glTranslatef (vertex_a[0], vertex_a[1], vertex_a[2]) );
+  _cogl_current_matrix_translate (vertex_a[0], vertex_a[1], vertex_a[2]);
   /* Rotate the plane by the calculated angle so that it will connect
      the two points */
-  GE( glRotatef (angle, 0.0f, 0.0f, 1.0f) );
+  _cogl_current_matrix_rotate (angle, 0.0f, 0.0f, 1.0f);
-  GE( glTranslatef (-vertex_a[0], -vertex_a[1], -vertex_a[2]) );
+  _cogl_current_matrix_translate (-vertex_a[0], -vertex_a[1], -vertex_a[2]);
 
   plane[0] = 0;
   plane[1] = -1.0;
@@ -426,7 +398,7 @@ set_clip_plane (GLint plane_num,
   GE( glClipPlane (plane_num, plane) );
 #endif
 
-  GE( glPopMatrix () );
+  _cogl_current_matrix_pop ();
 }
 
 void
@@ -435,7 +407,10 @@ _cogl_set_clip_planes (float x_offset,
 		       float width,
 		       float height)
 {
-  GLfloat modelview[16], projection[16];
+  CoglMatrix modelview_matrix;
+  CoglMatrix projection_matrix;
+  GLfloat *modelview;
+  GLfloat *projection;
 
   float vertex_tl[4] = { x_offset, y_offset, 0, 1.0 };
   float vertex_tr[4] = { x_offset + width, y_offset, 0, 1.0 };
@@ -443,8 +418,18 @@ _cogl_set_clip_planes (float x_offset,
   float vertex_br[4] = { x_offset + width, y_offset + height,
                         0, 1.0 };
 
-  GE( glGetFloatv (GL_MODELVIEW_MATRIX, modelview) );
+  /* hack alert: there's no way to get *and modify*
-  GE( glGetFloatv (GL_PROJECTION_MATRIX, projection) );
+   * CoglMatrix as a float array. So we just
+   * use a cast instead of cogl_matrix_get_array(),
+   * and know that we will not call any more CoglMatrix
+   * methods after we write to it directly.
+   */
+  _cogl_get_matrix (COGL_MATRIX_PROJECTION,
+                    &projection_matrix);
+  projection = (GLfloat*) &projection_matrix;
+  _cogl_get_matrix (COGL_MATRIX_MODELVIEW,
+                    &modelview_matrix);
+  modelview = (GLfloat*) &modelview_matrix;
 
   project_vertex (modelview, projection, vertex_tl);
   project_vertex (modelview, projection, vertex_tr);
@@ -513,15 +498,15 @@ _cogl_add_stencil_clip (float x_offset,
 	 only pixels where both the original stencil buffer and the
 	 rectangle are set will be valid */
       GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
-      GE( glMatrixMode (GL_PROJECTION) );
+      _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
-      GE( glMatrixMode (GL_MODELVIEW) );
+      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
     }
 
   /* Restore the stencil mode */
@@ -529,14 +514,6 @@ _cogl_add_stencil_clip (float x_offset,
   GE( glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );
 }
 
-void
-_cogl_set_matrix (const CoglMatrix *matrix)
-{
-  const GLfloat *gl_matrix = cogl_matrix_get_array (matrix);
-
-  GE (glLoadMatrixf (gl_matrix));
-}
-
 void
 _cogl_disable_stencil_buffer (void)
 {
@@ -561,108 +538,6 @@ _cogl_disable_clip_planes (void)
   GE( glDisable (GL_CLIP_PLANE0) );
 }
 
-void
-cogl_perspective (float fovy,
-		  float aspect,
-		  float zNear,
-		  float zFar)
-{
-  float xmax, ymax;
-  float x, y, c, d;
-  float fovy_rad_half = (fovy * G_PI) / 360;
-
-  GLfloat m[16];
-
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  memset (&m[0], 0, sizeof (m));
-
-  GE( glMatrixMode (GL_PROJECTION) );
-  GE( glLoadIdentity () );
-
-  /*
-   * Based on the original algorithm in perspective():
-   *
-   * 1) xmin = -xmax => xmax + xmin == 0 && xmax - xmin == 2 * xmax
-   * same true for y, hence: a == 0 && b == 0;
-   *
-   * 2) When working with small numbers, we are loosing significant
-   * precision
-   */
-  ymax = (zNear * (sinf (fovy_rad_half) / cosf (fovy_rad_half)));
-  xmax = (ymax * aspect);
-
-  x = (zNear / xmax);
-  y = (zNear / ymax);
-  c = (-(zFar + zNear) / ( zFar - zNear));
-  d = (-(2 * zFar) * zNear) / (zFar - zNear);
-
-#define M(row,col)  m[col*4+row]
-  M(0,0) = x;
-  M(1,1) = y;
-  M(2,2) = c;
-  M(2,3) = d;
-  M(3,2) = -1.0;
-
-  GE( glMultMatrixf (m) );
-
-  GE( glMatrixMode (GL_MODELVIEW) );
-
-  /* Calculate and store the inverse of the matrix */
-  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
-
-#define m ctx->inverse_projection
-  M(0, 0) = (1.0 / x);
-  M(1, 1) = (1.0 / y);
-  M(2, 3) = -1.0;
-  M(3, 2) = (1.0 / d);
-  M(3, 3) = (c / d);
-#undef m
-
-#undef M
-}
-
-void
-cogl_frustum (float        left,
-	      float        right,
-	      float        bottom,
-	      float        top,
-	      float        z_near,
-	      float        z_far)
-{
-  float c, d;
-
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  GE( glMatrixMode (GL_PROJECTION) );
-  GE( glLoadIdentity () );
-
-  GE( glFrustum ((GLdouble)(left),
-		 (GLdouble)(right),
-		 (GLdouble)(bottom),
-		 (GLdouble)(top),
-		 (GLdouble)(z_near),
-		 (GLdouble)(z_far)) );
-
-  GE( glMatrixMode (GL_MODELVIEW) );
-
-  /* Calculate and store the inverse of the matrix */
-  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
-
-  c = - (z_far + z_near) /  (z_far - z_near);
-  d = - (2 * (z_far * z_near)) /  (z_far - z_near);
-
-#define M(row,col)  ctx->inverse_projection[col*4+row]
-  M(0,0) =  (right - left) /  (2 * z_near);
-  M(0,3) =  (right + left) /  (2 * z_near);
-  M(1,1) =  (top - bottom) /  (2 * z_near);
-  M(1,3) =  (top + bottom) /  (2 * z_near);
-  M(2,3) = -1.0;
-  M(3,2) = 1.0 / d;
-  M(3,3) = c / d;
-#undef M
-}
-
 void
 cogl_viewport (guint width,
 	       guint height)
@@ -684,7 +559,7 @@ cogl_setup_viewport (guint width,
   GE( glViewport (0, 0, width, height) );
 
   /* For Ortho projection.
-   * glOrthof (0, width << 16, 0,  height << 16,  -1 << 16, 1 << 16);
+   * _cogl_current_matrix_ortho (0, width << 16, 0,  height << 16,  -1 << 16, 1 << 16);
    */
 
   cogl_perspective (fovy, aspect, z_near, z_far);
@@ -731,11 +606,10 @@ cogl_setup_viewport (guint width,
   cogl_get_projection_matrix (&projection_matrix);
   z_camera = 0.5 * projection_matrix.xx;
 
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
-
+  _cogl_current_matrix_translate (-0.5f, -0.5f, -z_camera);
-  GE( glTranslatef (-0.5f, -0.5f, -z_camera) );
+  _cogl_current_matrix_scale (1.0f / width, -1.0f / height, 1.0f / width);
-  GE( glScalef (1.0f / width, -1.0f / height, 1.0f / width) );
+  _cogl_current_matrix_translate (0.0f, -1.0 * height, 0.0f);
-  GE( glTranslatef (0.0f, -1.0 * height, 0.0f) );
 }
 
 #ifdef HAVE_CLUTTER_OSX
@@ -1122,28 +996,6 @@ cogl_features_available (CoglFeatureFlags features)
   return (ctx->feature_flags & features) == features;
 }
 
-void
-cogl_get_modelview_matrix (CoglMatrix *matrix)
-{
-  float m[16];
-  glGetFloatv (GL_MODELVIEW_MATRIX, m);
-  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
-   * any flag members, we could avoid this extra copy if it really
-   * bothers anyone */
-  cogl_matrix_init_from_array (matrix, m);
-}
-
-void
-cogl_get_projection_matrix (CoglMatrix *matrix)
-{
-  float m[16];
-  glGetFloatv (GL_PROJECTION_MATRIX, m);
-  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
-   * any flag members, we could avoid this extra copy if it really
-   * bothers anyone */
-  cogl_matrix_init_from_array (matrix, m);
-}
-
 void
 cogl_get_viewport (float v[4])
 {
@@ -1234,3 +1086,8 @@ cogl_disable_fog (void)
   glDisable (GL_FOG);
 }
 
+void
+cogl_flush_gl_state (int flags)
+{
+  _cogl_current_matrix_state_flush ();
+}

gles/cogl-context.c

@@ -39,6 +39,7 @@
 #include <string.h>
 
 static CoglContext *_context = NULL;
+static gboolean gl_is_indirect = FALSE;
 
 gboolean
 cogl_create_context ()
@@ -61,6 +62,8 @@ cogl_create_context ()
 
   _context->enable_backface_culling = FALSE;
 
+  _context->indirect = gl_is_indirect;
+
   _context->material_handles = NULL;
   _context->material_layer_handles = NULL;
   _context->default_material = cogl_material_new ();
@@ -104,6 +107,9 @@ cogl_create_context ()
   /* Initialise the clip stack */
   _cogl_clip_stack_state_init ();
 
+  /* Initialise matrix stack */
+  _cogl_current_matrix_state_init ();
+
   /* Create default textures used for fall backs */
   _context->default_gl_texture_2d_tex =
     cogl_texture_new_from_data (1, /* width */
@@ -143,6 +149,8 @@ cogl_destroy_context ()
 
   _cogl_clip_stack_state_destroy ();
 
+  _cogl_current_matrix_state_destroy ();
+
   if (_context->path_nodes)
     g_array_free (_context->path_nodes, TRUE);
 
@@ -187,3 +195,32 @@ _cogl_context_get_default ()
 
   return _context;
 }
+
+/**
+ * _cogl_set_indirect_context:
+ * @indirect: TRUE if GL context is indirect
+ *
+ * Advises COGL that the GL context is indirect (commands are sent
+ * over a socket). COGL uses this information to try to avoid
+ * round-trips in its use of GL, for example.
+ *
+ * This function cannot be called "on the fly," only before COGL
+ * initializes.
+ */
+void
+_cogl_set_indirect_context (gboolean indirect)
+{
+  /* we get called multiple times if someone creates
+   * more than the default stage
+   */
+  if (_context != NULL)
+    {
+      if (indirect != _context->indirect)
+        g_warning ("Right now all stages will be treated as "
+                   "either direct or indirect, ignoring attempt "
+                   "to change to indirect=%d", indirect);
+      return;
+    }
+
+  gl_is_indirect = indirect;
+}

gles/cogl-context.h

@@ -28,6 +28,8 @@
 
 #include "cogl-primitives.h"
 #include "cogl-clip-stack.h"
+#include "cogl-matrix-stack.h"
+#include "cogl-current-matrix.h"
 
 #include "cogl-gles2-wrapper.h"
 
@@ -50,6 +52,12 @@ typedef struct
 
   gboolean          enable_backface_culling;
 
+  gboolean          indirect;
+
+  /* Client-side matrix stack or NULL if none */
+  CoglMatrixMode    matrix_mode;
+  CoglMatrixStack  *modelview_stack;
+
   /* Cache of inverse projection matrix */
   float            inverse_projection[16];
 

gles/cogl-fbo.c

@@ -206,33 +206,29 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
              from a non-screen buffer */
 	  GE( glGetIntegerv (GL_VIEWPORT, ctx->viewport_store) );
 
-	  GE( glMatrixMode (GL_PROJECTION) );
+          _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glPushMatrix () );
+          _cogl_current_matrix_push ();
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+          _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glPushMatrix () );
+          _cogl_current_matrix_push ();
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 	}
       else
 	{
 	  /* Override viewport and matrix setup if redirecting
              from another offscreen buffer */
-	  GE( glMatrixMode (GL_PROJECTION) );
+          _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+          _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glLoadIdentity () );
+          _cogl_current_matrix_identity ();
 	}
 
       /* Setup new viewport and matrices */
       GE( glViewport (0, 0, fbo->width, fbo->height) );
-      GE( glTranslatef (-1.0, -1.0, 0) );
+      _cogl_current_matrix_translate (-1.0f, -1.0f, 0.0f);
-      GE( glScalef (((float)(2) /
+      _cogl_current_matrix_scale (2.0f / fbo->width, 2.0f / fbo->height, 1.0f);
-                                (float)(fbo->width)),
-			      ((float)(2) /
-                                (float)(fbo->height)),
-			      1.0) );
 
       /* Bind offscreen framebuffer object */
       GE( glBindFramebuffer (GL_FRAMEBUFFER, fbo->gl_handle) );
@@ -265,11 +261,11 @@ cogl_draw_buffer (CoglBufferTarget target, CoglHandle offscreen)
 	  GE( glViewport (ctx->viewport_store[0], ctx->viewport_store[1],
 			  ctx->viewport_store[2], ctx->viewport_store[3]) );
 
-	  GE( glMatrixMode (GL_PROJECTION) );
+           _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-	  GE( glPopMatrix () );
+           _cogl_current_matrix_pop ();
 
-	  GE( glMatrixMode (GL_MODELVIEW) );
+           _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-	  GE( glPopMatrix () );
+           _cogl_current_matrix_pop ();
 	}
 
       /* Bind window framebuffer object */

gles/cogl-primitives.c

@@ -87,6 +87,7 @@ _cogl_path_stroke_nodes ()
                                 COGL_MATERIAL_FLUSH_DISABLE_MASK,
                                 (guint32)~0, /* disable all texture layers */
                                 NULL);
+  _cogl_current_matrix_state_flush ();
 
   while (path_start < ctx->path_nodes->len)
     {
@@ -167,6 +168,7 @@ _cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
   GE( glColorMask (FALSE, FALSE, FALSE, FALSE) );
   GE( glDepthMask (FALSE) );
 
+  _cogl_current_matrix_state_flush ();
   while (path_start < path_size)
     {
       GE( glVertexPointer (2, GL_FLOAT, sizeof (CoglPathNode),
@@ -202,16 +204,18 @@ _cogl_add_path_to_stencil_buffer (floatVec2 nodes_min,
       GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
       /* Decrement all of the bits twice so that only pixels where the
          value is 3 will remain */
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
-      GE( glMatrixMode (GL_PROJECTION) );
+
-      GE( glPushMatrix () );
+      _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_push ();
+      _cogl_current_matrix_identity ();
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
-      GE( glMatrixMode (GL_MODELVIEW) );
+
-      GE( glPopMatrix () );
+      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+      _cogl_current_matrix_pop ();
     }
 
   GE( glStencilMask (~(GLuint) 0) );

gles/cogl-texture.c

@@ -504,18 +504,18 @@ _cogl_texture_download_from_gl (CoglTexture *tex,
      (0,0 in bottom-left corner to draw the texture
      upside-down so we match the way glReadPixels works) */
 
-  GE( glMatrixMode (GL_PROJECTION) );
+  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-  GE( glPushMatrix () );
+  _cogl_current_matrix_push ();
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
 
-  GE( glOrthof (0, (float)(viewport[2]),
+  _cogl_current_matrix_ortho (0, (float)(viewport[2]),
                               0, (float)(viewport[3]),
                               (float)(0),
-			  (float)(100)) );
+                              (float)(100));
 
-  GE( glMatrixMode (GL_MODELVIEW) );
+  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-  GE( glPushMatrix () );
+  _cogl_current_matrix_push ();
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
 
   /* Draw to all channels */
   cogl_draw_buffer (COGL_WINDOW_BUFFER | COGL_MASK_BUFFER, 0);
@@ -611,10 +611,10 @@ _cogl_texture_download_from_gl (CoglTexture *tex,
     }
 
   /* Restore old state */
-  glMatrixMode (GL_PROJECTION);
+  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-  glPopMatrix ();
+  _cogl_current_matrix_pop ();
-  glMatrixMode (GL_MODELVIEW);
+  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-  glPopMatrix ();
+  _cogl_current_matrix_pop ();
 
   cogl_draw_buffer (COGL_WINDOW_BUFFER, 0);
 
@@ -2169,7 +2169,7 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
   cogl_enable (enable_flags);
 
   GE (glVertexPointer (2, GL_FLOAT, stride, vertex_pointer));
-
+  _cogl_current_matrix_state_flush ();
   GE (glDrawRangeElements (GL_TRIANGLES,
                            0, ctx->static_indices->len - 1,
                            6 * batch_len,
@@ -2198,6 +2198,7 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
                                       color == 2 ? 0xff : 0x00,
                                       0xff);
           cogl_material_flush_gl_state (outline, NULL);
+          _cogl_current_matrix_state_flush ();
           GE( glDrawArrays (GL_LINE_LOOP, 4 * i, 4) );
         }
     }
@@ -2986,6 +2987,7 @@ _cogl_texture_sliced_polygon (CoglTextureVertex *vertices,
                                         COGL_MATERIAL_FLUSH_LAYER0_OVERRIDE,
                                         gl_handle,
                                         NULL);
+          _cogl_current_matrix_state_flush ();
 
 	  GE( glDrawArrays (GL_TRIANGLE_FAN, 0, n_vertices) );
 	}
@@ -3069,6 +3071,7 @@ _cogl_multitexture_unsliced_polygon (CoglTextureVertex *vertices,
                                 COGL_MATERIAL_FLUSH_FALLBACK_MASK,
                                 fallback_mask,
                                 NULL);
+  _cogl_current_matrix_state_flush ();
 
   GE (glDrawArrays (GL_TRIANGLE_FAN, 0, n_vertices));
 }

gles/cogl.c

@@ -124,37 +124,6 @@ cogl_clear (const CoglColor *color)
    */
 }
 
-/* FIXME: inline most of these  */
-void
-cogl_push_matrix (void)
-{
-  GE( glPushMatrix() );
-}
-
-void
-cogl_pop_matrix (void)
-{
-  GE( glPopMatrix() );
-}
-
-void
-cogl_scale (float x, float y, float z)
-{
-  GE( glScalef (x, y, z) );
-}
-
-void
-cogl_translate (float x, float y, float z)
-{
-  GE( glTranslatef (x, y, z) );
-}
-
-void
-cogl_rotate (float angle, float x, float y, float z)
-{
-  GE( glRotatef (angle, x, y, z) );
-}
-
 static inline gboolean
 cogl_toggle_flag (CoglContext *ctx,
 		  gulong new_flags,
@@ -319,6 +288,7 @@ set_clip_plane (GLint plane_num,
   GLdouble plane[4];
 #endif
   GLfloat angle;
+  CoglMatrix inverse_projection;
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
   /* Calculate the angle between the axes and the line crossing the
@@ -326,18 +296,20 @@ set_clip_plane (GLint plane_num,
   angle = atan2f (vertex_b[1] - vertex_a[1],
                   vertex_b[0] - vertex_a[0]) * (180.0/G_PI);
 
-  GE( glPushMatrix () );
+  _cogl_current_matrix_push ();
   /* Load the identity matrix and multiply by the reverse of the
      projection matrix so we can specify the plane in screen
      coordinates */
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
-  GE( glMultMatrixf ((GLfloat *) ctx->inverse_projection) );
+  cogl_matrix_init_from_array (&inverse_projection,
+                               ctx->inverse_projection);
+  _cogl_current_matrix_multiply (&inverse_projection);
   /* Rotate about point a */
-  GE( glTranslatef (vertex_a[0], vertex_a[1], vertex_a[2]) );
+  _cogl_current_matrix_translate (vertex_a[0], vertex_a[1], vertex_a[2]);
   /* Rotate the plane by the calculated angle so that it will connect
      the two points */
-  GE( glRotatef (angle, 0.0f, 0.0f, 1.0f) );
+  _cogl_current_matrix_rotate (angle, 0.0f, 0.0f, 1.0f);
-  GE( glTranslatef (-vertex_a[0], -vertex_a[1], -vertex_a[2]) );
+  _cogl_current_matrix_translate (-vertex_a[0], -vertex_a[1], -vertex_a[2]);
 
   plane[0] = 0;
   plane[1] = -1.0;
@@ -349,7 +321,7 @@ set_clip_plane (GLint plane_num,
   GE( glClipPlane (plane_num, plane) );
 #endif
 
-  GE( glPopMatrix () );
+  _cogl_current_matrix_pop ();
 }
 
 void
@@ -358,7 +330,10 @@ _cogl_set_clip_planes (float x_offset,
 		       float width,
 		       float height)
 {
-  GLfloat modelview[16], projection[16];
+  CoglMatrix modelview_matrix;
+  CoglMatrix projection_matrix;
+  GLfloat *modelview;
+  GLfloat *projection;
 
   float vertex_tl[4] = { x_offset, y_offset, 0, 1.0 };
   float vertex_tr[4] = { x_offset + width, y_offset, 0, 1.0 };
@@ -366,8 +341,18 @@ _cogl_set_clip_planes (float x_offset,
   float vertex_br[4] = { x_offset + width, y_offset + height,
                         0, 1.0 };
 
-  GE( glGetFloatv (GL_MODELVIEW_MATRIX, modelview) );
+  /* hack alert: there's no way to get *and modify*
-  GE( glGetFloatv (GL_PROJECTION_MATRIX, projection) );
+   * CoglMatrix as a float array. So we just
+   * use a cast instead of cogl_matrix_get_array(),
+   * and know that we will not call any more CoglMatrix
+   * methods after we write to it directly.
+   */
+  _cogl_get_matrix (COGL_MATRIX_PROJECTION,
+                    &projection_matrix);
+  projection = (GLfloat*) &projection_matrix;
+  _cogl_get_matrix (COGL_MATRIX_MODELVIEW,
+                    &modelview_matrix);
+  modelview = (GLfloat*) &modelview_matrix;
 
   project_vertex (modelview, projection, vertex_tl);
   project_vertex (modelview, projection, vertex_tr);
@@ -436,15 +421,15 @@ _cogl_add_stencil_clip (float x_offset,
 	 only pixels where both the original stencil buffer and the
 	 rectangle are set will be valid */
       GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
-      GE( glMatrixMode (GL_PROJECTION) );
+      _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
-      GE( glPushMatrix () );
+      _cogl_current_matrix_push ();
-      GE( glLoadIdentity () );
+      _cogl_current_matrix_identity ();
       cogl_rectangle (-1.0, -1.0, 1.0, 1.0);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
-      GE( glMatrixMode (GL_MODELVIEW) );
+      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
-      GE( glPopMatrix () );
+      _cogl_current_matrix_pop ();
     }
 
   /* Restore the stencil mode */
@@ -452,14 +437,6 @@ _cogl_add_stencil_clip (float x_offset,
   GE( glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );
 }
 
-void
-_cogl_set_matrix (const CoglMatrix *matrix)
-{
-  const GLfloat *gl_matrix = cogl_matrix_get_array (matrix);
-
-  GE (glLoadMatrixf (gl_matrix));
-}
-
 void
 _cogl_disable_stencil_buffer (void)
 {
@@ -484,108 +461,6 @@ _cogl_disable_clip_planes (void)
   GE( glDisable (GL_CLIP_PLANE0) );
 }
 
-void
-cogl_perspective (float fovy,
-		  float aspect,
-		  float zNear,
-		  float zFar)
-{
-  float xmax, ymax;
-  float x, y, c, d;
-  float fovy_rad_half = (fovy * G_PI) / 360;
-
-  GLfloat m[16];
-
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  memset (&m[0], 0, sizeof (m));
-
-  GE( glMatrixMode (GL_PROJECTION) );
-  GE( glLoadIdentity () );
-
-  /*
-   * Based on the original algorithm in perspective():
-   *
-   * 1) xmin = -xmax => xmax + xmin == 0 && xmax - xmin == 2 * xmax
-   * same true for y, hence: a == 0 && b == 0;
-   *
-   * 2) When working with small numbers, we are loosing significant
-   * precision
-   */
-  ymax = (zNear * (sinf (fovy_rad_half) / cosf (fovy_rad_half)));
-  xmax = (ymax * aspect);
-
-  x = (zNear / xmax);
-  y = (zNear / ymax);
-  c = (-(zFar + zNear) / ( zFar - zNear));
-  d = (-(2 * zFar) * zNear) / (zFar - zNear);
-
-#define M(row,col)  m[col*4+row]
-  M(0,0) = x;
-  M(1,1) = y;
-  M(2,2) = c;
-  M(2,3) = d;
-  M(3,2) = -1.0;
-
-  GE( glMultMatrixf (m) );
-
-  GE( glMatrixMode (GL_MODELVIEW) );
-
-  /* Calculate and store the inverse of the matrix */
-  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
-
-#define m ctx->inverse_projection
-  M(0, 0) = (1.0 / x);
-  M(1, 1) = (1.0 / y);
-  M(2, 3) = -1.0;
-  M(3, 2) = (1.0 / d);
-  M(3, 3) = (c / d);
-#undef m
-
-#undef M
-}
-
-void
-cogl_frustum (float        left,
-	      float        right,
-	      float        bottom,
-	      float        top,
-	      float        z_near,
-	      float        z_far)
-{
-  float c, d;
-
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  GE( glMatrixMode (GL_PROJECTION) );
-  GE( glLoadIdentity () );
-
-  GE( glFrustumf (left,
-                  right,
-		  bottom,
-                  top,
-		  z_near,
-                  z_far) );
-
-  GE( glMatrixMode (GL_MODELVIEW) );
-
-  /* Calculate and store the inverse of the matrix */
-  memset (ctx->inverse_projection, 0, sizeof (float) * 16);
-
-  c = - (z_far + z_near) /  (z_far - z_near);
-  d = - (2 * (z_far * z_near)) /  (z_far - z_near);
-
-#define M(row,col)  ctx->inverse_projection[col*4+row]
-  M(0,0) =  (right - left) /  (2 * z_near);
-  M(0,3) =  (right + left) /  (2 * z_near);
-  M(1,1) =  (top - bottom) /  (2 * z_near);
-  M(1,3) =  (top + bottom) /  (2 * z_near);
-  M(2,3) = -1.0;
-  M(3,2) = 1.0 / d;
-  M(3,3) = c / d;
-#undef M
-}
-
 void
 cogl_viewport (guint width,
 	       guint height)
@@ -607,7 +482,7 @@ cogl_setup_viewport (guint width,
   GE( glViewport (0, 0, width, height) );
 
   /* For Ortho projection.
-   * glOrthof (0, width << 16, 0,  height << 16,  -1 << 16, 1 << 16);
+   * _cogl_current_matrix_ortho (0, width << 16, 0,  height << 16,  -1 << 16, 1 << 16);
    */
 
   cogl_perspective (fovy, aspect, z_near, z_far);
@@ -621,13 +496,10 @@ cogl_setup_viewport (guint width,
   cogl_get_projection_matrix (&projection_matrix);
   z_camera = 0.5 * projection_matrix.xx;
 
-  GE( glLoadIdentity () );
+  _cogl_current_matrix_identity ();
-
+  _cogl_current_matrix_translate (-0.5f, -0.5f, -z_camera);
-  GE( glTranslatef (-0.5f, -0.5f, -z_camera) );
+  _cogl_current_matrix_scale (1.0f / width, -1.0f / height, 1.0f / width);
-
+  _cogl_current_matrix_translate (0.0f, -1.0 * height, 0.0f);
-  GE( glScalef (1.0f / width, -1.0f / height, 1.0f / width) );
-
-  GE( glTranslatef (0.0f, -1.0 * height, 0.0f) );
 }
 
 static void
@@ -679,28 +551,6 @@ cogl_features_available (CoglFeatureFlags features)
   return (ctx->feature_flags & features) == features;
 }
 
-void
-cogl_get_modelview_matrix (CoglMatrix *matrix)
-{
-  float m[16];
-  glGetFloatv (GL_MODELVIEW_MATRIX, m);
-  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
-   * any flag members, we could avoid this extra copy if it really
-   * bothers anyone */
-  cogl_matrix_init_from_array (matrix, m);
-}
-
-void
-cogl_get_projection_matrix (CoglMatrix *matrix)
-{
-  float m[16];
-  glGetFloatv (GL_PROJECTION_MATRIX, m);
-  /* Since it's internal to Cogl and CoglMatrix doesn't currently have
-   * any flag members, we could avoid this extra copy if it really
-   * bothers anyone */
-  cogl_matrix_init_from_array (matrix, m);
-}
-
 void
 cogl_get_viewport (float v[4])
 {
@@ -796,3 +646,8 @@ cogl_disable_fog (void)
   glDisable (GL_FOG);
 }
 
+void
+cogl_flush_gl_state (int flags)
+{
+  _cogl_current_matrix_state_flush ();
+}