mesa: check for no state change in Enable/DisableVertexAttribArray()

Avoid setting dirty state flags when enabling or disabling a vertex
attribute arrays when there's no change.

Reviewed-by: José Fonseca <jfonseca@vmware.com>

diff --git a/src/mesa/main/varray.c b/src/mesa/main/varray.c
index dfe5064e3c002b6fbbed6c388ef622f40854c483..93f6fcd9bea0cdd25b9322b4e068a8d2ba6c7b3e 100644 (file)
--- a/src/mesa/main/varray.c
+++ b/src/mesa/main/varray.c
@@ -483,6 +483,7 @@ _mesa_VertexAttribIPointer(GLuint index, GLint size, GLenum type,
 void GLAPIENTRY
 _mesa_EnableVertexAttribArrayARB(GLuint index)
 {
+   struct gl_array_object *arrayObj;
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);
 
@@ -492,18 +493,24 @@ _mesa_EnableVertexAttribArrayARB(GLuint index)
       return;
    }
 
-   ASSERT(VERT_ATTRIB_GENERIC(index) < Elements(ctx->Array.ArrayObj->VertexAttrib));
+   arrayObj = ctx->Array.ArrayObj;
+
+   ASSERT(VERT_ATTRIB_GENERIC(index) < Elements(arrayObj->VertexAttrib));
 
-   FLUSH_VERTICES(ctx, _NEW_ARRAY);
-   ctx->Array.ArrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled = GL_TRUE;
-   ctx->Array.ArrayObj->_Enabled |= VERT_BIT_GENERIC(index);
-   ctx->Array.NewState |= VERT_BIT_GENERIC(index);
+   if (!arrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled) {
+      /* was disabled, now being enabled */
+      FLUSH_VERTICES(ctx, _NEW_ARRAY);
+      arrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled = GL_TRUE;
+      arrayObj->_Enabled |= VERT_BIT_GENERIC(index);
+      ctx->Array.NewState |= VERT_BIT_GENERIC(index);
+   }
 }
 
 
 void GLAPIENTRY
 _mesa_DisableVertexAttribArrayARB(GLuint index)
 {
+   struct gl_array_object *arrayObj;
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);
 
@@ -513,12 +520,17 @@ _mesa_DisableVertexAttribArrayARB(GLuint index)
       return;
    }
 
-   ASSERT(VERT_ATTRIB_GENERIC(index) < Elements(ctx->Array.ArrayObj->VertexAttrib));
+   arrayObj = ctx->Array.ArrayObj;
+
+   ASSERT(VERT_ATTRIB_GENERIC(index) < Elements(arrayObj->VertexAttrib));
 
-   FLUSH_VERTICES(ctx, _NEW_ARRAY);
-   ctx->Array.ArrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled = GL_FALSE;
-   ctx->Array.ArrayObj->_Enabled &= ~VERT_BIT_GENERIC(index);
-   ctx->Array.NewState |= VERT_BIT_GENERIC(index);
+   if (arrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled) {
+      /* was enabled, now being disabled */
+      FLUSH_VERTICES(ctx, _NEW_ARRAY);
+      arrayObj->VertexAttrib[VERT_ATTRIB_GENERIC(index)].Enabled = GL_FALSE;
+      arrayObj->_Enabled &= ~VERT_BIT_GENERIC(index);
+      ctx->Array.NewState |= VERT_BIT_GENERIC(index);
+   }
 }