Use GL_QUADS for flushing a quad batch

Instead of using GL_TRIANGLES and uploading the indices every time, it
now uses GL_QUADS instead on OpenGL. Under GLES it still uses indices
but it uses the new cogl_vertex_buffer_indices_get_for_quads function
to avoid uploading the vertices every time.

This requires the _cogl_vertex_buffer_indices_pointer_from_handle
function to be exposed privately to the rest of Cogl.

The static_indices array has been removed from the Cogl context.

common/cogl-primitives.c

@@ -30,6 +30,7 @@
 #include "cogl-context.h"
 #include "cogl-texture-private.h"
 #include "cogl-material-private.h"
+#include "cogl-vertex-buffer-private.h"
 
 #include <string.h>
 #include <gmodule.h>
@@ -39,16 +40,8 @@
 
 #ifdef HAVE_COGL_GL
 
-#define glDrawRangeElements ctx->pf_glDrawRangeElements
 #define glClientActiveTexture ctx->pf_glClientActiveTexture
 
-#else
-
-/* GLES doesn't have glDrawRangeElements, so we simply pretend it does
- * but that it makes no use of the start, end constraints: */
-#define glDrawRangeElements(mode, start, end, count, type, indices) \
-  glDrawElements (mode, count, type, indices)
-
 #endif
 
 /* these are defined in the particular backend */
@@ -63,7 +56,6 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
                                 gint              batch_len,
                                 GLfloat          *vertex_pointer)
 {
-  int     needed_indices;
   gsize   stride;
   int     i;
   gulong  enable_flags = 0;
@@ -122,52 +114,31 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
   GE (glVertexPointer (2, GL_FLOAT, stride, vertex_pointer));
   _cogl_current_matrix_state_flush ();
 
+#ifdef HAVE_COGL_GL
 
-  if (batch_len > 1)
+  GE( glDrawArrays (GL_QUADS, 0, batch_len * 4) );
+
+#else /* HAVE_COGL_GL */
+
+  /* GLES doesn't support GL_QUADS so we will use GL_TRIANGLES and
+     indices */
   {
-      /* The indices are always the same sequence regardless of the vertices so
+    int needed_indices = batch_len * 6;
-       * we only need to change it if there are more vertices than ever before.
+    CoglHandle indices_handle
-       */
+      = cogl_vertex_buffer_indices_get_for_quads (needed_indices);
-      needed_indices = batch_len * 6;
+    CoglVertexBufferIndices *indices
-      if (needed_indices > ctx->static_indices->len)
+      = _cogl_vertex_buffer_indices_pointer_from_handle (indices_handle);
-        {
-          int old_len = ctx->static_indices->len;
-          int vert_num = old_len / 6 * 4;
-          GLushort *q;
 
-          /* Add two triangles for each quad to the list of
+    GE (glBindBuffer (GL_ELEMENT_ARRAY_BUFFER,
-             indices. That makes six new indices but two of the
+                      GPOINTER_TO_UINT (indices->vbo_name)));
-             vertices in the triangles are shared. */
+    GE (glDrawElements (GL_TRIANGLES,
-          g_array_set_size (ctx->static_indices, needed_indices);
-          q = &g_array_index (ctx->static_indices, GLushort, old_len);
-
-          for (i = old_len;
-               i < ctx->static_indices->len;
-               i += 6, vert_num += 4)
-            {
-              *(q++) = vert_num + 0;
-              *(q++) = vert_num + 1;
-              *(q++) = vert_num + 3;
-
-              *(q++) = vert_num + 1;
-              *(q++) = vert_num + 2;
-              *(q++) = vert_num + 3;
-            }
-        }
-
-      GE (glDrawRangeElements (GL_TRIANGLES,
-                               0, ctx->static_indices->len - 1,
                         6 * batch_len,
-                               GL_UNSIGNED_SHORT,
+                        indices->type,
-                               ctx->static_indices->data));
+                        NULL));
-    }
+    GE (glBindBuffer (GL_ELEMENT_ARRAY_BUFFER, 0));
-  else
-    {
-      GE (glDrawArrays (GL_TRIANGLE_FAN,
-                        0, /* first */
-                        4)); /* n vertices */
   }
 
+#endif /* HAVE_COGL_GL */
 
   /* DEBUGGING CODE XXX:
    * This path will cause all rectangles to be drawn with a red, green

common/cogl-vertex-buffer-private.h

@@ -161,5 +161,9 @@ typedef struct _CoglVertexBuffer
 
 } CoglVertexBuffer;
 
+CoglVertexBuffer *_cogl_vertex_buffer_pointer_from_handle (CoglHandle handle);
+CoglVertexBufferIndices *
+     _cogl_vertex_buffer_indices_pointer_from_handle (CoglHandle handle);
+
 #endif /* __COGL_VERTEX_BUFFER_H */
 

gl/cogl-context.c

@@ -69,7 +69,6 @@ cogl_create_context ()
 
   _context->journal = g_array_new (FALSE, FALSE, sizeof (CoglJournalEntry));
   _context->logged_vertices = g_array_new (FALSE, FALSE, sizeof (GLfloat));
-  _context->static_indices = g_array_new (FALSE, FALSE, sizeof (GLushort));
   _context->polygon_vertices = g_array_new (FALSE, FALSE,
                                             sizeof (CoglTextureGLVertex));
 
@@ -204,8 +203,6 @@ _cogl_destroy_context ()
   if (_context->logged_vertices)
     g_array_free (_context->logged_vertices, TRUE);
 
-  if (_context->static_indices)
-    g_array_free (_context->static_indices, TRUE);
   if (_context->polygon_vertices)
     g_array_free (_context->polygon_vertices, TRUE);
   if (_context->current_layers)

gl/cogl-context.h

@@ -78,7 +78,6 @@ typedef struct
    * can batch things together. */
   GArray           *journal;
   GArray           *logged_vertices;
-  GArray           *static_indices;
   GArray           *polygon_vertices;
 
   /* Some simple caching, to minimize state changes... */

gles/cogl-context.c

@@ -72,7 +72,6 @@ cogl_create_context ()
 
   _context->journal = g_array_new (FALSE, FALSE, sizeof (CoglJournalEntry));
   _context->logged_vertices = g_array_new (FALSE, FALSE, sizeof (GLfloat));
-  _context->static_indices = g_array_new (FALSE, FALSE, sizeof (GLushort));
   _context->polygon_vertices = g_array_new (FALSE, FALSE,
                                             sizeof (CoglTextureGLVertex));
 
@@ -162,8 +161,6 @@ _cogl_destroy_context ()
   if (_context->logged_vertices)
     g_array_free (_context->logged_vertices, TRUE);
 
-  if (_context->static_indices)
-    g_array_free (_context->static_indices, TRUE);
   if (_context->polygon_vertices)
     g_array_free (_context->polygon_vertices, TRUE);
   if (_context->current_layers)

gles/cogl-context.h

@@ -80,7 +80,6 @@ typedef struct
    * can batch things together. */
   GArray           *journal;
   GArray           *logged_vertices;
-  GArray           *static_indices;
   GArray           *polygon_vertices;
 
   /* Some simple caching, to minimize state changes... */