Mesa (master): mesa: don' t draw arrays if vertex position array is not enabled

[Brian Paul]

Module: Mesa
Branch: master
Commit: 97dd2ddbd97ba95e8bc8ab572ec05e8081556e1e
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=97dd2ddbd97ba95e8bc8ab572ec05e8081556e1e

Author: Brian Paul <brianp at vmware.com>
Date:   Mon Mar  2 12:27:16 2009 -0700

mesa: don't draw arrays if vertex position array is not enabled

For regular GL, we must have vertex positions in order to draw.  But ES2
doesn't have that requirement (positions can be computed from any array
of data).

See bug 19911.

---

 src/mesa/main/api_validate.c |   15 ++++++++++++---
 1 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 5c8955d..42d1e57 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -87,11 +87,20 @@ check_valid_to_render(GLcontext *ctx, char *function)
       return GL_FALSE;
    }
 
-   /* Always need vertex positions, unless a vertex program is in use */
-   if (!ctx->VertexProgram._Current &&
-       !ctx->Array.ArrayObj->Vertex.Enabled &&
+#if FEATURE_es2_glsl
+   /* For ES2, we can draw if any vertex array is enabled (and we should
+    * always have a vertex program/shader).
+    */
+   if (ctx->Array.ArrayObj->_Enabled == 0x0 || !ctx->VertexProgram._Current)
+      return GL_FALSE;
+#else
+   /* For regular OpenGL, only draw if we have vertex positions (regardless
+    * of whether or not we have a vertex program/shader).
+    */
+   if (!ctx->Array.ArrayObj->Vertex.Enabled &&
        !ctx->Array.ArrayObj->VertexAttrib[0].Enabled)
       return GL_FALSE;
+#endif
 
    return GL_TRUE;
 }