[Mesa-dev] [PATCH 2/5] mesa: Do a draw time check for TES && !TCS in ES 3.x.

[Kenneth Graunke]

ES 3.x requires both TCS and TES to be present.  We already checked
the TCS && !TES case above, so we just have to check !TCS && TES here.

Note that this is allowed in OpenGL, just not ES.

This fixes a subcase of:
dEQP-GLES31.functional.debug.negative_coverage.*.tessellation.single_tessellation_stage

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/mesa/main/api_validate.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index d64264fe1e9..41d2611eec4 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -257,6 +257,20 @@ check_valid_to_render(struct gl_context *ctx, const char *function)
 
    switch (ctx->API) {
    case API_OPENGLES2:
+      /* Section 11.2 (Tessellation) of the ES 3.2 spec says:
+       *
+       * "An INVALID_OPERATION error is generated by any command that
+       *  transfers vertices to the GL if the current program state has
+       *  one but not both of a tessellation control shader and tessellation
+       *  evaluation shader."
+       */
+      if (_mesa_is_gles3(ctx) &&
+          ctx->TessEvalProgram._Current && !ctx->TessCtrlProgram._Current) {
+         _mesa_error(ctx, GL_INVALID_OPERATION,
+                     "%s(tess ctrl shader is missing)", function);
+         return false;
+      }
+
       /* For ES2, we can draw if we have a vertex program/shader). */
       return ctx->VertexProgram._Current != NULL;
 
-- 
2.11.1