cogl: Remove unused cogl_{begin,end}_gl API

Any GL calls we want to make should be inside cogl already.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/500

cogl/cogl/cogl-context-private.h

@@ -231,8 +231,6 @@ struct _CoglContext
   CoglIndices      *rectangle_short_indices;
   int               rectangle_short_indices_len;
 
-  gboolean          in_begin_gl_block;
-
   CoglPipeline     *texture_download_pipeline;
   CoglPipeline     *blit_texture_pipeline;
 

cogl/cogl/cogl-context.c

@@ -347,8 +347,6 @@ cogl_context_new (CoglDisplay *display,
   context->current_path = NULL;
   context->stencil_pipeline = cogl_pipeline_new (context);
 
-  context->in_begin_gl_block = FALSE;
-
   context->quad_buffer_indices_byte = NULL;
   context->quad_buffer_indices = NULL;
   context->quad_buffer_indices_len = 0;

cogl/cogl/cogl.c

@@ -347,82 +347,6 @@ cogl_read_pixels (int x,
   cogl_object_unref (bitmap);
 }
 
-void
-cogl_begin_gl (void)
-{
-  CoglPipeline *pipeline;
-
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  if (ctx->in_begin_gl_block)
-    {
-      static gboolean shown = FALSE;
-      if (!shown)
-        g_warning ("You should not nest cogl_begin_gl/cogl_end_gl blocks");
-      shown = TRUE;
-      return;
-    }
-  ctx->in_begin_gl_block = TRUE;
-
-  /* Flush all batched primitives */
-  cogl_flush ();
-
-  /* Flush framebuffer state, including clip state, modelview and
-   * projection matrix state
-   *
-   * NB: _cogl_framebuffer_flush_state may disrupt various state (such
-   * as the pipeline state) when flushing the clip stack, so should
-   * always be done first when preparing to draw. */
-  _cogl_framebuffer_flush_state (cogl_get_draw_framebuffer (),
-                                 _cogl_get_read_framebuffer (),
-                                 COGL_FRAMEBUFFER_STATE_ALL);
-
-  /* Setup the state for the current pipeline */
-
-  /* We considered flushing a specific, minimal pipeline here to try and
-   * simplify the GL state, but decided to avoid special cases and second
-   * guessing what would be actually helpful.
-   *
-   * A user should instead call cogl_set_source_color4ub() before
-   * cogl_begin_gl() to simplify the state flushed.
-   *
-   * XXX: note defining n_tex_coord_attribs using
-   * cogl_pipeline_get_n_layers is a hack, but the problem is that
-   * n_tex_coord_attribs is usually defined when drawing a primitive
-   * which isn't happening here.
-   *
-   * Maybe it would be more useful if this code did flush the
-   * opaque_color_pipeline and then call into cogl-pipeline-opengl.c to then
-   * restore all state for the material's backend back to default OpenGL
-   * values.
-   */
-  pipeline = cogl_get_source ();
-  _cogl_pipeline_flush_gl_state (ctx,
-                                 pipeline,
-                                 cogl_get_draw_framebuffer (),
-                                 FALSE,
-                                 FALSE);
-
-  /* Disable any cached vertex arrays */
-  _cogl_gl_disable_all_attributes (ctx);
-}
-
-void
-cogl_end_gl (void)
-{
-  _COGL_GET_CONTEXT (ctx, NO_RETVAL);
-
-  if (!ctx->in_begin_gl_block)
-    {
-      static gboolean shown = FALSE;
-      if (!shown)
-        g_warning ("cogl_end_gl is being called before cogl_begin_gl");
-      shown = TRUE;
-      return;
-    }
-  ctx->in_begin_gl_block = FALSE;
-}
-
 void
 cogl_push_matrix (void)
 {

cogl/cogl/cogl.symbols

@@ -38,8 +38,6 @@ cogl_attribute_set_buffer
 cogl_attribute_set_normalized
 cogl_attribute_type_get_type
 
-cogl_begin_gl
-
 cogl_bitmap_error_get_type
 cogl_bitmap_get_buffer
 cogl_bitmap_get_format
@@ -198,8 +196,6 @@ cogl_display_set_onscreen_template
 
 cogl_double_to_fixed
 
-cogl_end_gl
-
 cogl_euler_copy
 cogl_euler_equal
 cogl_euler_free

cogl/cogl/cogl1-context.h

@@ -766,97 +766,6 @@ cogl_set_source_texture (CoglTexture *texture);
 void
 cogl_flush (void);
 
-/**
- * cogl_begin_gl:
- *
- * We do not advise nor reliably support the interleaving of raw GL drawing and
- * Cogl drawing functions, but if you insist, cogl_begin_gl() and cogl_end_gl()
- * provide a simple mechanism that may at least give you a fighting chance of
- * succeeding.
- *
- * Note: this doesn't help you modify the behaviour of Cogl drawing functions
- * through the modification of GL state; that will never be reliably supported,
- * but if you are trying to do something like:
- *
- * |[
- * {
- *    - setup some OpenGL state.
- *    - draw using OpenGL (e.g. glDrawArrays() )
- *    - reset modified OpenGL state.
- *    - continue using Cogl to draw
- * }
- * ]|
- *
- * You should surround blocks of drawing using raw GL with cogl_begin_gl()
- * and cogl_end_gl():
- *
- * |[
- * {
- *    cogl_begin_gl ();
- *    - setup some OpenGL state.
- *    - draw using OpenGL (e.g. glDrawArrays() )
- *    - reset modified OpenGL state.
- *    cogl_end_gl ();
- *    - continue using Cogl to draw
- * }
- * ]|
- *
- * Don't ever try and do:
- *
- * |[
- * {
- *    - setup some OpenGL state.
- *    - use Cogl to draw
- *    - reset modified OpenGL state.
- * }
- * ]|
- *
- * When the internals of Cogl evolves, this is very liable to break.
- *
- * This function will flush all batched primitives, and subsequently flush
- * all internal Cogl state to OpenGL as if it were going to draw something
- * itself.
- *
- * The result is that the OpenGL modelview matrix will be setup; the state
- * corresponding to the current source material will be set up and other world
- * state such as backface culling, depth and fogging enabledness will be sent
- * to OpenGL.
- *
- * <note>No special material state is flushed, so if you want Cogl to setup a
- * simplified material state it is your responsibility to set a simple source
- * material before calling cogl_begin_gl(). E.g. by calling
- * cogl_set_source_color4ub().</note>
- *
- * <note>It is your responsibility to restore any OpenGL state that you modify
- * to how it was after calling cogl_begin_gl() if you don't do this then the
- * result of further Cogl calls is undefined.</note>
- *
- * <note>You can not nest begin/end blocks.</note>
- *
- * Again we would like to stress, we do not advise the use of this API and if
- * possible we would prefer to improve Cogl than have developers require raw
- * OpenGL.
- *
- * Since: 1.0
- * Deprecated: 1.16: Use the #CoglGLES2Context api instead
- */
-COGL_DEPRECATED_FOR (CoglGLES2Context_API)
-void
-cogl_begin_gl (void);
-
-/**
- * cogl_end_gl:
- *
- * This is the counterpart to cogl_begin_gl() used to delimit blocks of drawing
- * code using raw OpenGL. Please refer to cogl_begin_gl() for full details.
- *
- * Since: 1.0
- * Deprecated: 1.16: Use the #CoglGLES2Context api instead
- */
-COGL_DEPRECATED_FOR (CoglGLES2Context_API)
-void
-cogl_end_gl (void);
-
 G_END_DECLS
 
 #endif /* __COGL_1_CONTEXT_H__ */

cogl/cogl/driver/gl/cogl-attribute-gl-private.h

@@ -47,7 +47,4 @@ _cogl_gl_flush_attributes_state (CoglFramebuffer *framebuffer,
                                  CoglAttribute **attributes,
                                  int n_attributes);
 
-void
-_cogl_gl_disable_all_attributes (CoglContext *ctx);
-
 #endif /* _COGL_ATTRIBUTE_GL_PRIVATE_H_ */

cogl/cogl/driver/gl/cogl-attribute-gl.c

@@ -523,16 +523,3 @@ _cogl_gl_flush_attributes_state (CoglFramebuffer *framebuffer,
   if (copy)
     cogl_object_unref (copy);
 }
-
-void
-_cogl_gl_disable_all_attributes (CoglContext *ctx)
-{
-  _cogl_bitmask_clear_all (&ctx->enable_builtin_attributes_tmp);
-  _cogl_bitmask_clear_all (&ctx->enable_texcoord_attributes_tmp);
-  _cogl_bitmask_clear_all (&ctx->enable_custom_attributes_tmp);
-
-  /* XXX: we can pass a NULL source pipeline here because we know a
-   * source pipeline only needs to be referenced when enabling
-   * attributes. */
-  apply_attribute_enable_updates (ctx, NULL);
-}