cogl: Remove always-set COGL_FEATURE_ID_OFFSCREEN

https://gitlab.gnome.org/GNOME/mutter/merge_requests/866

cogl/cogl/cogl-atlas-texture.c

@@ -729,18 +729,6 @@ allocate_space (CoglAtlasTexture *atlas_tex,
       return FALSE;
     }
 
-  /* If we can't use FBOs then it will be too slow to migrate textures
-     and we shouldn't use the atlas */
-  if (!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-    {
-      g_set_error_literal (error,
-                           COGL_SYSTEM_ERROR,
-                           COGL_SYSTEM_ERROR_UNSUPPORTED,
-                           "Atlasing disabled because migrations "
-                           "would be too slow");
-      return FALSE;
-    }
-
   /* Look for an existing atlas that can hold the texture */
   for (l = ctx->atlases; l; l = l->next)
     {

cogl/cogl/cogl-context.h

@@ -177,7 +177,6 @@ cogl_is_context (void *object);
  * @COGL_FEATURE_ID_TEXTURE_RG: Support for
  *    %COGL_TEXTURE_COMPONENTS_RG as the internal components of a
  *    texture.
- * @COGL_FEATURE_ID_OFFSCREEN: Offscreen rendering support
  * @COGL_FEATURE_ID_OFFSCREEN_MULTISAMPLE: Multisample support for
  *    offscreen framebuffers
  * @COGL_FEATURE_ID_ONSCREEN_MULTIPLE: Multiple onscreen framebuffers
@@ -208,7 +207,6 @@ cogl_is_context (void *object);
  */
 typedef enum _CoglFeatureID
 {
-  COGL_FEATURE_ID_OFFSCREEN,
   COGL_FEATURE_ID_OFFSCREEN_MULTISAMPLE,
   COGL_FEATURE_ID_ONSCREEN_MULTIPLE,
   COGL_FEATURE_ID_UNSIGNED_INT_INDICES,

cogl/cogl/cogl-framebuffer.c

@@ -728,14 +728,6 @@ cogl_framebuffer_allocate (CoglFramebuffer *framebuffer,
     {
       CoglOffscreen *offscreen = COGL_OFFSCREEN (framebuffer);
 
-      if (!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-        {
-          g_set_error_literal (error, COGL_SYSTEM_ERROR,
-                               COGL_SYSTEM_ERROR_UNSUPPORTED,
-                               "Offscreen framebuffers not supported by system");
-          return FALSE;
-        }
-
       if (!cogl_texture_allocate (offscreen->texture, error))
         return FALSE;
 

cogl/cogl/cogl-texture.c

@@ -546,9 +546,6 @@ get_texture_bits_via_offscreen (CoglTexture *meta_texture,
   GError *ignore_error = NULL;
   CoglPixelFormat real_format;
 
-  if (!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-    return FALSE;
-
   offscreen = _cogl_offscreen_new_with_texture_full
                                       (sub_texture,
                                        COGL_OFFSCREEN_DISABLE_DEPTH_AND_STENCIL,

cogl/cogl/driver/gl/cogl-framebuffer-gl.c

@@ -279,9 +279,7 @@ _cogl_framebuffer_gl_bind (CoglFramebuffer *framebuffer, GLenum target)
       const CoglWinsysVtable *winsys =
         _cogl_framebuffer_get_winsys (framebuffer);
       winsys->onscreen_bind (COGL_ONSCREEN (framebuffer));
-      /* glBindFramebuffer is an an extension with OpenGL ES 1.1 */
+      GE (ctx, glBindFramebuffer (target, 0));
-      if (cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-        GE (ctx, glBindFramebuffer (target, 0));
 
       /* Initialise the glDrawBuffer state the first time the context
        * is bound to the default framebuffer. If the winsys is using a

cogl/cogl/driver/gl/cogl-texture-2d-gl.c

@@ -238,35 +238,6 @@ allocate_from_bitmap (CoglTexture2D *tex_2d,
                                           NULL,
                                           NULL);
 
-  /* Keep a copy of the first pixel so that if glGenerateMipmap isn't
-     supported we can fallback to using GL_GENERATE_MIPMAP */
-  if (!cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-    {
-      GError *ignore = NULL;
-      uint8_t *data = _cogl_bitmap_map (upload_bmp,
-                                        COGL_BUFFER_ACCESS_READ, 0,
-                                        &ignore);
-      CoglPixelFormat format = cogl_bitmap_get_format (upload_bmp);
-
-      tex_2d->first_pixel.gl_format = gl_format;
-      tex_2d->first_pixel.gl_type = gl_type;
-
-      if (data)
-        {
-          memcpy (tex_2d->first_pixel.data, data,
-                  cogl_pixel_format_get_bytes_per_pixel (format, 0));
-          _cogl_bitmap_unmap (upload_bmp);
-        }
-      else
-        {
-          g_warning ("Failed to read first pixel of bitmap for "
-                     "glGenerateMipmap fallback");
-          g_error_free (ignore);
-          memset (tex_2d->first_pixel.data, 0,
-                  cogl_pixel_format_get_bytes_per_pixel (format, 0));
-        }
-    }
-
   tex_2d->gl_texture =
     ctx->texture_driver->gen (ctx, GL_TEXTURE_2D, internal_format);
   if (!ctx->texture_driver->upload_to_gl (ctx,
@@ -724,32 +695,7 @@ _cogl_texture_2d_gl_get_gl_handle (CoglTexture2D *tex_2d)
 void
 _cogl_texture_2d_gl_generate_mipmap (CoglTexture2D *tex_2d)
 {
-  CoglContext *ctx = COGL_TEXTURE (tex_2d)->context;
+  _cogl_texture_gl_generate_mipmaps (COGL_TEXTURE (tex_2d));
-
-  /* glGenerateMipmap is defined in the FBO extension. If it's not
-     available we'll fallback to temporarily enabling
-     GL_GENERATE_MIPMAP and reuploading the first pixel */
-  if (cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-    _cogl_texture_gl_generate_mipmaps (COGL_TEXTURE (tex_2d));
-#ifdef HAVE_COGL_GL
-  else
-    {
-      _cogl_bind_gl_texture_transient (GL_TEXTURE_2D,
-                                       tex_2d->gl_texture,
-                                       tex_2d->is_foreign);
-
-      GE( ctx, glTexParameteri (GL_TEXTURE_2D,
-                                GL_GENERATE_MIPMAP,
-                                GL_TRUE) );
-      GE( ctx, glTexSubImage2D (GL_TEXTURE_2D, 0, 0, 0, 1, 1,
-                                tex_2d->first_pixel.gl_format,
-                                tex_2d->first_pixel.gl_type,
-                                tex_2d->first_pixel.data) );
-      GE( ctx, glTexParameteri (GL_TEXTURE_2D,
-                                GL_GENERATE_MIPMAP,
-                                GL_FALSE) );
-    }
-#endif
 }
 
 gboolean
@@ -793,36 +739,6 @@ _cogl_texture_2d_gl_copy_from_bitmap (CoglTexture2D *tex_2d,
                                           &gl_format,
                                           &gl_type);
 
-  /* If this touches the first pixel then we'll update our copy */
-  if (dst_x == 0 && dst_y == 0 &&
-      !cogl_has_feature (ctx, COGL_FEATURE_ID_OFFSCREEN))
-    {
-      GError *ignore = NULL;
-      uint8_t *data =
-        _cogl_bitmap_map (upload_bmp, COGL_BUFFER_ACCESS_READ, 0, &ignore);
-      int bpp = cogl_pixel_format_get_bytes_per_pixel (upload_format, 0);
-
-      tex_2d->first_pixel.gl_format = gl_format;
-      tex_2d->first_pixel.gl_type = gl_type;
-
-      if (data)
-        {
-          memcpy (tex_2d->first_pixel.data,
-                  (data +
-                   cogl_bitmap_get_rowstride (upload_bmp) * src_y +
-                   bpp * src_x),
-                  bpp);
-          _cogl_bitmap_unmap (bmp);
-        }
-      else
-        {
-          g_warning ("Failed to read first bitmap pixel for "
-                     "glGenerateMipmap fallback");
-          g_error_free (ignore);
-          memset (tex_2d->first_pixel.data, 0, bpp);
-        }
-    }
-
   status = ctx->texture_driver->upload_subregion_to_gl (ctx,
                                                         tex,
                                                         FALSE,

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

@@ -416,7 +416,6 @@ _cogl_driver_update_features (CoglContext *ctx,
       return FALSE;
     }
   flags |= COGL_FEATURE_OFFSCREEN;
-  COGL_FLAGS_SET (ctx->features, COGL_FEATURE_ID_OFFSCREEN, TRUE);
   COGL_FLAGS_SET (private_features,
                   COGL_PRIVATE_FEATURE_QUERY_FRAMEBUFFER_BITS,
                   TRUE);

cogl/cogl/driver/gl/gles/cogl-driver-gles.c

@@ -304,7 +304,6 @@ _cogl_driver_update_features (CoglContext *context,
   flags |= COGL_FEATURE_OFFSCREEN;
   /* Note GLES 2 core doesn't support mipmaps for npot textures or
    * repeat modes other than CLAMP_TO_EDGE. */
-  COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_OFFSCREEN, TRUE);
 
   COGL_FLAGS_SET (private_features, COGL_PRIVATE_FEATURE_ANY_GL, TRUE);
   COGL_FLAGS_SET (private_features, COGL_PRIVATE_FEATURE_ALPHA_TEXTURES, TRUE);
@@ -312,7 +311,6 @@ _cogl_driver_update_features (CoglContext *context,
   if (context->glGenRenderbuffers)
     {
       flags |= COGL_FEATURE_OFFSCREEN;
-      COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_OFFSCREEN, TRUE);
     }
 
   if (context->glBlitFramebuffer)

cogl/cogl/winsys/cogl-winsys-glx.c

@@ -2223,19 +2223,15 @@ get_fbconfig_for_depth (CoglContext *context,
 
       stencil = value;
 
-      /* glGenerateMipmap is defined in the offscreen extension */
+      glx_renderer->glXGetFBConfigAttrib (dpy,
-      if (cogl_has_feature (context, COGL_FEATURE_ID_OFFSCREEN))
+                                          fbconfigs[i],
-        {
+                                          GLX_BIND_TO_MIPMAP_TEXTURE_EXT,
-          glx_renderer->glXGetFBConfigAttrib (dpy,
+                                          &value);
-                                              fbconfigs[i],
-                                              GLX_BIND_TO_MIPMAP_TEXTURE_EXT,
-                                              &value);
 
-          if (value < mipmap)
+      if (value < mipmap)
-            continue;
+        continue;
 
-          mipmap =  value;
+      mipmap = value;
-        }
 
       *fbconfig_ret = fbconfigs[i];
       *can_mipmap_ret = mipmap;

cogl/test-fixtures/test-utils.c

@@ -36,12 +36,6 @@ check_flags (TestFlags flags,
       return FALSE;
     }
 
-  if (flags & TEST_REQUIREMENT_OFFSCREEN &&
-      !cogl_has_feature (test_ctx, COGL_FEATURE_ID_OFFSCREEN))
-    {
-      return FALSE;
-    }
-
   if (flags & TEST_REQUIREMENT_FENCE &&
       !cogl_has_feature (test_ctx, COGL_FEATURE_ID_FENCE))
     {