[current-matrix] Adds texture matrix stacks + removes GL matrix API usage

This relates back to an earlier commitment to stop using the OpenGL matrix
API which is considered deprecated. (ref 54159f5a1d)

The new texture matrix stacks are hung from a list of (internal only)
CoglTextureUnit structures which the CoglMaterial code internally references
via _cogl_get_texure_unit ().

So we would be left with only the cogl-matrix-stack code being responsible
for glMatrixMode, glLoadMatrix and glLoadIdentity this commit updates the
journal code so it now uses the matrix-stack API instead of GL directly.

clutter/cogl/cogl/cogl-context.c

@@ -65,6 +65,8 @@ cogl_create_context (void)
 
   _context->indirect = gl_is_indirect;
 
+  _context->texture_units = NULL;
+
   _context->default_material = cogl_material_new ();
   _context->source_material = NULL;
 
@@ -151,6 +153,8 @@ _cogl_destroy_context ()
 
   _cogl_current_matrix_state_destroy ();
 
+  _cogl_destroy_texture_units ();
+
   if (_context->path_nodes)
     g_array_free (_context->path_nodes, TRUE);
 

clutter/cogl/cogl/cogl-context.h

@@ -58,10 +58,11 @@ typedef struct
 
   gboolean          indirect;
 
-  /* Client-side matrix stack or NULL if none */
   CoglMatrixMode    matrix_mode;
-  CoglMatrixStack  *modelview_stack;
   CoglMatrixStack  *projection_stack;
+  CoglMatrixStack  *modelview_stack;
+
+  GList            *texture_units;
 
   /* Cache of inverse projection matrix */
   float            inverse_projection[16];

clutter/cogl/cogl/cogl-current-matrix.c

@@ -59,14 +59,21 @@ _cogl_get_client_stack (CoglContext      *ctx,
                         CoglMatrixMode    mode,
                         CoglMatrixStack **current_stack_p)
 {
-  if (ctx->modelview_stack &&
+  switch (mode)
-      mode == COGL_MATRIX_MODELVIEW)
+    {
+    case COGL_MATRIX_MODELVIEW:
       *current_stack_p = ctx->modelview_stack;
-  else if (ctx->projection_stack &&
+      break;
-           mode == COGL_MATRIX_PROJECTION)
+    case COGL_MATRIX_PROJECTION:
       *current_stack_p = ctx->projection_stack;
-  else
+      break;
+    case COGL_MATRIX_TEXTURE:
+      g_critical ("The current-matrix API doesn't support the texture matrix "
+                  "you must deal with the CoglMatrixStack directly");
       *current_stack_p  = NULL;
+      break;
+    }
+  g_assert (*current_stack_p);
 }
 
 #define _COGL_GET_CONTEXT_AND_STACK(contextvar, stackvar, rval) \
@@ -77,90 +84,46 @@ _cogl_get_client_stack (CoglContext      *ctx,
 void
 _cogl_set_current_matrix (CoglMatrixMode mode)
 {
-  GLenum gl_mode;
-  CoglMatrixStack *current_stack;                                    \
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
   if (mode == ctx->matrix_mode)
     return;
   ctx->matrix_mode = mode;
-
-  /* If we have a client side stack then then the GL matrix mode only needs
-   * changing when we come to flush it to OpenGL */
-  _cogl_get_client_stack (ctx, mode, &current_stack);
-  if (current_stack)
-    return;
-
-  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));
 }
 
 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
@@ -170,11 +133,7 @@ _cogl_current_matrix_rotate (float angle,
                              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
@@ -183,11 +142,7 @@ _cogl_current_matrix_scale (float x,
                             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
@@ -196,11 +151,7 @@ _cogl_current_matrix_translate (float x,
                                 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
@@ -212,15 +163,11 @@ _cogl_current_matrix_frustum (float left,
                               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,
                               bottom, top,
                               near_val,
                               far_val);
-  else
-    GE (glFrustum (left, right, bottom, top, near_val, far_val));
 }
 
 void
@@ -230,20 +177,8 @@ _cogl_current_matrix_perspective (float fov_y,
                                   float z_far)
 {
   _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
-
-  if (current_stack != NULL)
   _cogl_matrix_stack_perspective (current_stack,
                                   fov_y, aspect, z_near, z_far);
-  else
-    {
-      /* NB: There is no glPerspective() (only gluPerspective()) so we use
-       * cogl_matrix_perspective: */
-      CoglMatrix matrix;
-      _cogl_get_matrix (ctx->matrix_mode, &matrix);
-      cogl_matrix_perspective (&matrix,
-                               fov_y, aspect, z_near, z_far);
-      _cogl_current_matrix_load (&matrix);
-    }
 }
 
 void
@@ -255,26 +190,11 @@ _cogl_current_matrix_ortho (float left,
                             float far_val)
 {
   _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
-
-  if (current_stack != NULL)
   _cogl_matrix_stack_ortho (current_stack,
                             left, right,
                             bottom, top,
                             near_val,
                             far_val);
-  else
-    {
-#ifdef HAVE_COGL_GLES2
-      /* NB: GLES 2 has no glOrtho(): */
-      CoglMatrix matrix;
-      _cogl_get_matrix (ctx->matrix_mode, &matrix);
-      cogl_matrix_ortho (&matrix,
-                         left, right, bottom, top, near_val, far_val);
-      _cogl_current_matrix_load (&matrix);
-#else
-      GE (glOrtho (left, right, bottom, top, near_val, far_val));
-#endif
-    }
 }
 
 void
@@ -286,36 +206,7 @@ _cogl_get_matrix (CoglMatrixMode mode,
 
   _cogl_get_client_stack (ctx, mode, &current_stack);
 
-  if (current_stack)
   _cogl_matrix_stack_get (current_stack, matrix);
-  else
-    {
-      GLenum gl_mode;
-      GLfloat gl_matrix[16];
-
-      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;
-        }
-
-      /* Note: we have a redundant copy happening here. If that turns out to be
-       * a problem then, since this is internal to Cogl, we could pass the
-       * CoglMatrix pointer directly to glGetFloatv; the only problem with that
-       * is that if we later add internal flags to CoglMatrix they will need to
-       * be initialized seperatly.
-       */
-      GE (glGetFloatv (gl_mode, gl_matrix));
-      cogl_matrix_init_from_array (matrix, gl_matrix);
-    }
 }
 
 void
@@ -330,61 +221,30 @@ _cogl_current_matrix_state_init (void)
   _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
   ctx->matrix_mode = COGL_MATRIX_MODELVIEW;
-  ctx->modelview_stack = NULL;
-  ctx->projection_stack = NULL;
-
-#if 0
-  if (ctx->indirect ||
-      cogl_debug_flags & COGL_DEBUG_FORCE_CLIENT_SIDE_MATRICES)
-#endif
-    {
-      ctx->modelview_stack = _cogl_matrix_stack_new ();
   ctx->projection_stack = _cogl_matrix_stack_new ();
-    }
+  ctx->modelview_stack = _cogl_matrix_stack_new ();
 }
 
 void
 _cogl_current_matrix_state_destroy (void)
 {
-  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
 
-  if (current_stack)
+  _cogl_matrix_stack_destroy (ctx->projection_stack);
-    _cogl_matrix_stack_destroy (current_stack);
+  _cogl_matrix_stack_destroy (ctx->modelview_stack);
 }
 
 void
 _cogl_current_matrix_state_flush (void)
 {
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+  _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
-
+  _cogl_matrix_stack_flush_to_gl (current_stack, ctx->matrix_mode);
-  if (ctx->matrix_mode != COGL_MATRIX_MODELVIEW &&
-      ctx->matrix_mode != COGL_MATRIX_PROJECTION)
-    {
-      g_warning ("matrix state must be flushed in "
-                 "MODELVIEW or PROJECTION mode");
-      return;
-    }
-
-  if (ctx->modelview_stack &&
-      ctx->matrix_mode == COGL_MATRIX_MODELVIEW)
-    {
-      _cogl_matrix_stack_flush_to_gl (ctx->modelview_stack,
-                                      GL_MODELVIEW);
-    }
-  else if (ctx->projection_stack &&
-           ctx->matrix_mode == COGL_MATRIX_PROJECTION)
-    {
-      _cogl_matrix_stack_flush_to_gl (ctx->projection_stack,
-                                      GL_PROJECTION);
-    }
 }
 
 void
 _cogl_current_matrix_state_dirty (void)
 {
   _COGL_GET_CONTEXT_AND_STACK (ctx, current_stack, NO_RETVAL);
-
-  if (current_stack)
   _cogl_matrix_stack_dirty (current_stack);
 }
 
@@ -541,9 +401,9 @@ cogl_set_projection_matrix (CoglMatrix *matrix)
 void
 _cogl_flush_matrix_stacks (void)
 {
-  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-  _cogl_current_matrix_state_flush ();
+
-  _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+  _cogl_matrix_stack_flush_to_gl (ctx->projection_stack, COGL_MATRIX_PROJECTION);
-  _cogl_current_matrix_state_flush ();
+  _cogl_matrix_stack_flush_to_gl (ctx->modelview_stack, COGL_MATRIX_MODELVIEW);
 }
 

clutter/cogl/cogl/cogl-internal.h

@@ -26,6 +26,7 @@
 
 #include "cogl-debug.h"
 #include "cogl-types.h"
+#include "cogl-context.h"
 
 #ifdef HAVE_COGL_GLES2
 typedef enum {
@@ -85,4 +86,15 @@ gint    _cogl_get_format_bpp (CoglPixelFormat format);
 void    cogl_enable (gulong flags);
 gulong  cogl_get_enable (void);
 
+typedef struct _CoglTextureUnit
+{
+  int              index;
+  CoglMatrixStack *matrix_stack;
+} CoglTextureUnit;
+
+CoglTextureUnit *
+_cogl_get_texture_unit (int index_);
+void
+_cogl_destroy_texture_units (void);
+
 #endif /* __COGL_INTERNAL_H */

clutter/cogl/cogl/cogl-journal.c

@@ -96,6 +96,7 @@ typedef struct _CoglJournalFlushState
   CoglJournalIndices *indices;
   size_t              indices_type_size;
 #endif
+  CoglMatrixStack    *modelview_stack;
 } CoglJournalFlushState;
 
 typedef void (*CoglJournalBatchCallback) (CoglJournalEntry *start,
@@ -193,7 +194,12 @@ _cogl_journal_flush_modelview_and_entries (CoglJournalEntry *batch_start,
     g_print ("BATCHING:    modelview batch len = %d\n", batch_len);
 
   if (G_UNLIKELY (cogl_debug_flags & COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM))
-    GE (glLoadMatrixf ((GLfloat *)&batch_start->model_view));
+    {
+      _cogl_matrix_stack_set (state->modelview_stack,
+                              &batch_start->model_view);
+      _cogl_matrix_stack_flush_to_gl (state->modelview_stack,
+                                      COGL_MATRIX_MODELVIEW);
+    }
 
 #ifdef HAVE_COGL_GL
 
@@ -541,21 +547,20 @@ _cogl_journal_flush (void)
   else
     state.vbo_offset = (char *)ctx->logged_vertices->data;
 
-  /* Since the journal deals with emitting the modelview matrices manually
+  _cogl_matrix_stack_flush_to_gl (ctx->projection_stack,
-   * we need to dirty our client side modelview matrix stack cache... */
+                                  COGL_MATRIX_PROJECTION);
-  _cogl_current_matrix_state_dirty ();
 
-  /* And explicitly flush other matrix stacks... */
+  state.modelview_stack = ctx->modelview_stack;
-  _cogl_set_current_matrix (COGL_MATRIX_PROJECTION);
+  _cogl_matrix_stack_push (ctx->modelview_stack);
-  _cogl_current_matrix_state_flush ();
 
-  /* If we have transformed all our quads at log time then the whole journal
+  /* If we have transformed all our quads at log time then we ensure no
-   * then we ensure no further model transform is applied by loading the
+   * further model transform is applied by loading the identity matrix
-   * identity matrix here...*/
+   * here... */
-  if (!(cogl_debug_flags & COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM))
+  if (G_LIKELY (!(cogl_debug_flags & COGL_DEBUG_DISABLE_SOFTWARE_TRANSFORM)))
     {
-      GE (glMatrixMode (GL_MODELVIEW));
+      _cogl_matrix_stack_load_identity (ctx->modelview_stack);
-      glLoadIdentity ();
+      _cogl_matrix_stack_flush_to_gl (ctx->modelview_stack,
+                                      COGL_MATRIX_MODELVIEW);
     }
 
   /* batch_and_call() batches a list of journal entries according to some
@@ -586,6 +591,8 @@ _cogl_journal_flush (void)
                   _cogl_journal_flush_vbo_offsets_and_entries, /* callback */
                   &state); /* data */
 
+  _cogl_matrix_stack_pop (ctx->modelview_stack);
+
   for (i = 0; i < ctx->journal->len; i++)
     {
       CoglJournalEntry *entry =

clutter/cogl/cogl/cogl-material.c

@@ -1169,8 +1169,11 @@ is_mipmap_filter (CoglMaterialFilter filter)
           || filter == COGL_MATERIAL_FILTER_LINEAR_MIPMAP_LINEAR);
 }
 
+/* FIXME: All direct manipulation of GL texture unit state should be dealt with
+ * by extending the CoglTextureUnit abstraction */
 static void
 _cogl_material_layer_flush_gl_sampler_state (CoglMaterialLayer  *layer,
+                                             CoglTextureUnit    *unit,
                                              CoglLayerInfo      *gl_layer_info)
 {
   int n_rgb_func_args;
@@ -1246,16 +1249,17 @@ _cogl_material_layer_flush_gl_sampler_state (CoglMaterialLayer  *layer,
                       layer->texture_combine_constant));
     }
 
-#ifndef DISABLE_MATERIAL_CACHE
   if ((gl_layer_info &&
        gl_layer_info->flags & COGL_MATERIAL_LAYER_FLAG_HAS_USER_MATRIX) ||
       (layer->flags & COGL_MATERIAL_LAYER_FLAG_HAS_USER_MATRIX))
-#endif
+    _cogl_matrix_stack_set (unit->matrix_stack, &layer->matrix);
-    {
+  else
-      _cogl_set_current_matrix (COGL_MATRIX_TEXTURE);
+    _cogl_matrix_stack_load_identity (unit->matrix_stack);
-      _cogl_current_matrix_load (&layer->matrix);
+
-      _cogl_set_current_matrix (COGL_MATRIX_MODELVIEW);
+  /* TODO: Eventually we should just have something like
-    }
+   * _cogl_flush_texture_units() that we can call in
+   * _cogl_material_flush_layers_gl_state */
+  _cogl_matrix_stack_flush_to_gl (unit->matrix_stack, COGL_MATRIX_TEXTURE);
 }
 
 /*
@@ -1327,6 +1331,7 @@ _cogl_material_flush_layers_gl_state (CoglMaterial *material,
 #ifdef HAVE_COGL_GLES2
       GLenum             gl_internal_format;
 #endif
+      CoglTextureUnit   *unit;
 
       new_gl_layer_info.layer0_overridden =
         layer0_override_texture ? TRUE : FALSE;
@@ -1366,6 +1371,7 @@ _cogl_material_flush_layers_gl_state (CoglMaterial *material,
         }
 
       GE (glActiveTexture (GL_TEXTURE0 + i));
+      unit = _cogl_get_texture_unit (i);
 
       _cogl_texture_set_filters (layer->texture,
                                  layer->min_filter,
@@ -1453,7 +1459,7 @@ _cogl_material_flush_layers_gl_state (CoglMaterial *material,
             }
         }
 
-      _cogl_material_layer_flush_gl_sampler_state (layer, gl_layer_info);
+      _cogl_material_layer_flush_gl_sampler_state (layer, unit, gl_layer_info);
 
       new_gl_layer_info.handle = layer_handle;
       new_gl_layer_info.flags = layer->flags;

clutter/cogl/cogl/cogl-matrix-stack.c

@@ -335,15 +335,28 @@ _cogl_matrix_stack_set (CoglMatrixStack  *stack,
 
 void
 _cogl_matrix_stack_flush_to_gl (CoglMatrixStack *stack,
-                                GLenum           gl_mode)
+                                CoglMatrixMode   mode)
 {
   CoglMatrixState *state;
+  GLenum gl_mode;
 
   state = _cogl_matrix_stack_top (stack);
 
   if (stack->flushed_state == state)
     return;
 
+  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));
 
   /* In theory it might help the GL implementation if we used our

clutter/cogl/cogl/cogl.c

@@ -877,3 +877,62 @@ cogl_end_gl (void)
   ctx->in_begin_gl_block = FALSE;
 }
 
+static CoglTextureUnit *
+_cogl_texture_unit_new (void)
+{
+  CoglTextureUnit *unit = g_new0 (CoglTextureUnit, 1);
+  unit->matrix_stack = _cogl_matrix_stack_new ();
+  return unit;
+}
+
+static void
+_cogl_texture_unit_free (CoglTextureUnit *unit)
+{
+  _cogl_matrix_stack_destroy (unit->matrix_stack);
+  g_free (unit);
+}
+
+CoglTextureUnit *
+_cogl_get_texture_unit (int index_)
+{
+  GList *l;
+  CoglTextureUnit *unit;
+
+  _COGL_GET_CONTEXT (ctx, NULL);
+
+  for (l = ctx->texture_units; l; l = l->next)
+    {
+      unit = l->data;
+
+      if (unit->index == index_)
+        return unit;
+
+      /* The units are always sorted, so at this point we know this unit
+       * doesn't exist */
+      if (unit->index > index_)
+        break;
+    }
+  /* NB: if we now insert a new layer before l, that will maintain order.
+   */
+
+  unit = _cogl_texture_unit_new ();
+
+  /* Note: see comment after for() loop above */
+  ctx->texture_units =
+    g_list_insert_before (ctx->texture_units, l, unit);
+
+  return unit;
+}
+
+void
+_cogl_destroy_texture_units (void)
+{
+  GList *l;
+
+  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
+
+  for (l = ctx->texture_units; l; l = l->next)
+    _cogl_texture_unit_free (l->data);
+  g_list_free (ctx->texture_units);
+}
+