From: Brian <brian@yutani.localnet.net>
Date: Wed, 7 Mar 2007 14:52:24 +0000 (-0700)
Subject: Generate an error if the vertex shader does not write to gl_Position.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=55821d021d87fba6551509f5612ee16d9ece977f;p=mesa.git

Generate an error if the vertex shader does not write to gl_Position.
---

diff --git a/src/mesa/shader/slang/slang_link.c b/src/mesa/shader/slang/slang_link.c
index 8f924739b49..e564d6d5767 100644
--- a/src/mesa/shader/slang/slang_link.c
+++ b/src/mesa/shader/slang/slang_link.c
@@ -548,8 +548,19 @@ _slang_link(GLcontext *ctx,
       }
    }
 
-   if (shProg->VertexProgram)
+   if (shProg->VertexProgram) {
       _slang_update_inputs_outputs(&shProg->VertexProgram->Base);
+      if (!(shProg->VertexProgram->Base.OutputsWritten & VERT_RESULT_HPOS)) {
+         /* the vertex program did not compute a vertex position */
+         if (shProg->InfoLog) {
+            _mesa_free(shProg->InfoLog);
+         }
+         shProg->InfoLog
+            = _mesa_strdup("gl_Position was not written by vertex shader");
+         shProg->LinkStatus = GL_FALSE;
+         return;
+      }
+   }
    if (shProg->FragmentProgram)
       _slang_update_inputs_outputs(&shProg->FragmentProgram->Base);