mesa: fix issues around multisample enable

multisample enable is enabled by default, however gl mandates multisample
rendering rules only apply if there's also a multisampled buffer.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/mesa/main/state.c b/src/mesa/main/state.c
index 315253d90a..344af91e17 100644
--- a/src/mesa/main/state.c
+++ b/src/mesa/main/state.c
@@ -289,6 +289,20 @@ update_viewport_matrix(GLcontext *ctx)
 
 
 /**
+ * Update derived multisample state.
+ */
+static void
+update_multisample(GLcontext *ctx)
+{
+   ctx->Multisample._Enabled = GL_FALSE;
+   if (ctx->DrawBuffer) {
+      if (ctx->DrawBuffer->Visual.sampleBuffers)
+         ctx->Multisample._Enabled = GL_TRUE;
+   }
+}
+
+
+/**
  * Update derived color/blend/logicop state.
  */
 static void
@@ -425,6 +439,9 @@ _mesa_update_state_locked( GLcontext *ctx )
    if (new_state & (_NEW_BUFFERS | _NEW_VIEWPORT))
       update_viewport_matrix(ctx);
 
+   if (new_state & _NEW_MULTISAMPLE)
+      update_multisample( ctx );
+
    if (new_state & _NEW_COLOR)
       update_color( ctx );