gallium: Delay the creation of simple helper shaders

1 files changed, 38 insertions, 16 deletions

diff --git a/src/mesa/state_tracker/st_cb_clear.c b/src/mesa/state_tracker/st_cb_clear.c
index 0e0c4326ed..1eb748e0d5 100644
--- a/src/mesa/state_tracker/st_cb_clear.c
+++ b/src/mesa/state_tracker/st_cb_clear.c
@@ -63,26 +63,12 @@
 void
 st_init_clear(struct st_context *st)
 {
-   struct pipe_context *pipe = st->pipe;
    struct pipe_screen *pscreen = st->pipe->screen;
 
    memset(&st->clear, 0, sizeof(st->clear));
 
    st->clear.raster.gl_rasterization_rules = 1;
    st->clear.enable_ds_separate = pscreen->get_param(pscreen, PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE);
-
-   /* fragment shader state: color pass-through program */
-   st->clear.fs = util_make_fragment_passthrough_shader(pipe);
-
-   /* vertex shader state: color/position pass-through */
-   {
-      const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
-                                      TGSI_SEMANTIC_COLOR };
-      const uint semantic_indexes[] = { 0, 0 };
-      st->clear.vs = util_make_vertex_passthrough_shader(pipe, 2,
-                                                         semantic_names,
-                                                         semantic_indexes);
-   }
 }
 
 
@@ -108,6 +94,42 @@ st_destroy_clear(struct st_context *st)
 
 
 /**
+ * Helper function to set the fragment shaders.
+ */
+static INLINE void
+set_fragment_shader(struct st_context *st)
+{
+   if (!st->clear.fs)
+      st->clear.fs = util_make_fragment_passthrough_shader(st->pipe);
+
+   cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
+}
+
+
+/**
+ * Helper function to set the vertex shader.
+ */
+static INLINE void
+set_vertex_shader(struct st_context *st)
+{
+   /* vertex shader - still required to provide the linkage between
+    * fragment shader input semantics and vertex_element/buffers.
+    */
+   if (!st->clear.vs)
+   {
+      const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
+                                      TGSI_SEMANTIC_COLOR };
+      const uint semantic_indexes[] = { 0, 0 };
+      st->clear.vs = util_make_vertex_passthrough_shader(st->pipe, 2,
+                                                         semantic_names,
+                                                         semantic_indexes);
+   }
+
+   cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
+}
+
+
+/**
  * Draw a screen-aligned quadrilateral.
  * Coords are clip coords with y=0=bottom.
  */
@@ -297,8 +319,8 @@ clear_with_quad(struct gl_context *ctx,
    }
 
    cso_set_clip(st->cso_context, &st->clear.clip);
-   cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
-   cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
+   set_fragment_shader(st);
+   set_vertex_shader(st);
 
    if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
       st_translate_color(ctx->Color.ClearColor,