[Mesa-dev] [PATCH 8/9] gallium/util: fix glClear with MRT by making the FS write to all cbufs

[Marek Olšák]

---
 src/gallium/auxiliary/util/u_simple_shaders.c |   34 ++++++++++++++++++++++---
 src/gallium/auxiliary/util/u_simple_shaders.h |    4 ++-
 src/gallium/state_trackers/vega/renderer.c    |    3 ++-
 src/gallium/tests/trivial/tri.c               |    3 ++-
 src/mesa/state_tracker/st_atom_shader.c       |    3 ++-
 src/mesa/state_tracker/st_cb_clear.c          |    4 ++-
 6 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/src/gallium/auxiliary/util/u_simple_shaders.c b/src/gallium/auxiliary/util/u_simple_shaders.c
index 5f0134d..7e36661 100644
--- a/src/gallium/auxiliary/util/u_simple_shaders.c
+++ b/src/gallium/auxiliary/util/u_simple_shaders.c
@@ -316,13 +316,39 @@ util_make_fragment_tex_shader_writestencil(struct pipe_context *pipe,
 
 
 /**
- * Make simple fragment color pass-through shader.
+ * Make simple fragment color pass-through shader that replicates OUT[0]
+ * to all bound colorbuffers.
  */
 void *
-util_make_fragment_passthrough_shader(struct pipe_context *pipe)
+util_make_fragment_passthrough_shader(struct pipe_context *pipe,
+                                      int input_semantic,
+                                      int input_interpolate)
 {
-   return util_make_fragment_cloneinput_shader(pipe, 1, TGSI_SEMANTIC_COLOR,
-                                               TGSI_INTERPOLATE_PERSPECTIVE);
+   static const char shader_templ[] =
+         "FRAG\n"
+         "PROPERTY FS_COLOR0_WRITES_ALL_CBUFS 1\n"
+         "DCL IN[0], %s[0], %s\n"
+         "DCL OUT[0], COLOR[0]\n"
+
+         "MOV OUT[0], IN[0]\n"
+         "END\n";
+
+   char text[sizeof(shader_templ)+100];
+   struct tgsi_token tokens[1000];
+   struct pipe_shader_state state = {tokens};
+
+   sprintf(text, shader_templ, tgsi_semantic_names[input_semantic],
+           tgsi_interpolate_names[input_interpolate]);
+
+   if (!tgsi_text_translate(text, tokens, Elements(tokens))) {
+      assert(0);
+      return NULL;
+   }
+#if 0
+   tgsi_dump(state.tokens, 0);
+#endif
+
+   return pipe->create_fs_state(pipe, &state);
 }
 
 
diff --git a/src/gallium/auxiliary/util/u_simple_shaders.h b/src/gallium/auxiliary/util/u_simple_shaders.h
index e4ffde6..22b9cee 100644
--- a/src/gallium/auxiliary/util/u_simple_shaders.h
+++ b/src/gallium/auxiliary/util/u_simple_shaders.h
@@ -87,7 +87,9 @@ util_make_fragment_tex_shader_writestencil(struct pipe_context *pipe,
 
 
 extern void *
-util_make_fragment_passthrough_shader(struct pipe_context *pipe);
+util_make_fragment_passthrough_shader(struct pipe_context *pipe,
+                                      int input_semantic,
+                                      int input_interpolate);
 
 
 extern void *
diff --git a/src/gallium/state_trackers/vega/renderer.c b/src/gallium/state_trackers/vega/renderer.c
index 11d3b5a..61e3105 100644
--- a/src/gallium/state_trackers/vega/renderer.c
+++ b/src/gallium/state_trackers/vega/renderer.c
@@ -308,7 +308,8 @@ static void renderer_set_fs(struct renderer *r, RendererFs id)
 
       switch (id) {
       case RENDERER_FS_COLOR:
-         fs = util_make_fragment_passthrough_shader(r->pipe);
+         fs = util_make_fragment_passthrough_shader(r->pipe,
+                          TGSI_SEMANTIC_COLOR, TGSI_INTERPOLATE_PERSPECTIVE);
          break;
       case RENDERER_FS_TEXTURE:
          fs = util_make_fragment_tex_shader(r->pipe,
diff --git a/src/gallium/tests/trivial/tri.c b/src/gallium/tests/trivial/tri.c
index ad88b86..9acf2e1 100644
--- a/src/gallium/tests/trivial/tri.c
+++ b/src/gallium/tests/trivial/tri.c
@@ -216,7 +216,8 @@ static void init_prog(struct program *p)
 	}
 
 	/* fragment shader */
-	p->fs = util_make_fragment_passthrough_shader(p->pipe);
+	p->fs = util_make_fragment_passthrough_shader(p->pipe,
+                    TGSI_SEMANTIC_COLOR, TGSI_INTERPOLATE_PERSPECTIVE);
 }
 
 static void close_prog(struct program *p)
diff --git a/src/mesa/state_tracker/st_atom_shader.c b/src/mesa/state_tracker/st_atom_shader.c
index 45e7a11..c1d7c80 100644
--- a/src/mesa/state_tracker/st_atom_shader.c
+++ b/src/mesa/state_tracker/st_atom_shader.c
@@ -59,7 +59,8 @@ get_passthrough_fs(struct st_context *st)
 {
    if (!st->passthrough_fs) {
       st->passthrough_fs =
-         util_make_fragment_passthrough_shader(st->pipe);
+         util_make_fragment_passthrough_shader(st->pipe, TGSI_SEMANTIC_COLOR,
+                                               TGSI_INTERPOLATE_PERSPECTIVE);
    }
 
    return st->passthrough_fs;
diff --git a/src/mesa/state_tracker/st_cb_clear.c b/src/mesa/state_tracker/st_cb_clear.c
index 5cf4c07..aabea63 100644
--- a/src/mesa/state_tracker/st_cb_clear.c
+++ b/src/mesa/state_tracker/st_cb_clear.c
@@ -96,7 +96,9 @@ static INLINE void
 set_fragment_shader(struct st_context *st)
 {
    if (!st->clear.fs)
-      st->clear.fs = util_make_fragment_passthrough_shader(st->pipe);
+      st->clear.fs =
+         util_make_fragment_passthrough_shader(st->pipe, TGSI_SEMANTIC_COLOR,
+                                               TGSI_INTERPOLATE_CONSTANT);
 
    cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
 }
-- 
1.7.10.4