[Mesa-dev] [PATCH 3/5] mesa/gles3: Generate error on DrawElements* calls if transform feedback active.

[Paul Berry]

In GLES3, only glDrawArrays() and glDrawArraysInstanced() calls are
allowed when transform feedback is active.
---
 src/mesa/main/api_validate.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index e47db23..355a93c 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -313,9 +313,24 @@ _mesa_validate_DrawElements(struct gl_context *ctx,
 			    GLenum mode, GLsizei count, GLenum type,
 			    const GLvoid *indices, GLint basevertex)
 {
+   struct gl_transform_feedback_object *xfb_obj
+      = ctx->TransformFeedback.CurrentObject;
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
    FLUSH_CURRENT(ctx, 0);
 
+   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
+    * Primitive Capture):
+    *
+    *   The error INVALID_OPERATION is also generated by DrawElements,
+    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
+    *   is active and not paused, regardless of mode.
+    */
+   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glDrawElements(transform feedback active)");
+      return GL_FALSE;
+   }
+
    if (count <= 0) {
       if (count < 0)
 	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawElements(count)" );
@@ -431,9 +446,24 @@ _mesa_validate_DrawRangeElements(struct gl_context *ctx, GLenum mode,
 				 GLsizei count, GLenum type,
 				 const GLvoid *indices, GLint basevertex)
 {
+   struct gl_transform_feedback_object *xfb_obj
+      = ctx->TransformFeedback.CurrentObject;
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
    FLUSH_CURRENT(ctx, 0);
 
+   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
+    * Primitive Capture):
+    *
+    *   The error INVALID_OPERATION is also generated by DrawElements,
+    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
+    *   is active and not paused, regardless of mode.
+    */
+   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glDrawElements(transform feedback active)");
+      return GL_FALSE;
+   }
+
    if (count <= 0) {
       if (count < 0)
 	 _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(count)" );
@@ -560,9 +590,24 @@ _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
                                      const GLvoid *indices, GLsizei numInstances,
                                      GLint basevertex)
 {
+   struct gl_transform_feedback_object *xfb_obj
+      = ctx->TransformFeedback.CurrentObject;
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
    FLUSH_CURRENT(ctx, 0);
 
+   /* From the GLES3 specification, section 2.14.2 (Transform Feedback
+    * Primitive Capture):
+    *
+    *   The error INVALID_OPERATION is also generated by DrawElements,
+    *   DrawElementsInstanced, and DrawRangeElements while transform feedback
+    *   is active and not paused, regardless of mode.
+    */
+   if (_mesa_is_gles3(ctx) && xfb_obj->Active && !xfb_obj->Paused) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glDrawElements(transform feedback active)");
+      return GL_FALSE;
+   }
+
    if (count <= 0) {
       if (count < 0)
 	 _mesa_error(ctx, GL_INVALID_VALUE,
-- 
1.8.0.2