mesa: added _mesa_is_fragment_shader_active() helper

src/mesa/main/shaderobj.h

@@ -130,6 +130,18 @@ _mesa_shader_index_to_type(GLuint i)
 }
 
 
+/**
+ * Check if there's a fragment shader active.
+ */
+static INLINE GLboolean
+_mesa_is_fragment_shader_active(const struct gl_context *ctx)
+{
+   return (ctx->Shader.CurrentProgram &&
+           ctx->Shader.CurrentProgram->LinkStatus &&
+           ctx->Shader.CurrentProgram->FragmentProgram);
+}
+
+
 #ifdef __cplusplus
 }
 #endif