From 493ed9fc11a2bf272a2c1e9e5a072e4f02b46554 Mon Sep 17 00:00:00 2001
From: Brian <brian.paul@tungstengraphics.com>
Date: Thu, 21 Jun 2007 20:08:10 -0600
Subject: [PATCH] alpha test and misc changes

---
 src/mesa/pipe/p_state.h                     |  2 +-
 src/mesa/pipe/softpipe/sp_context.h         |  1 +
 src/mesa/pipe/softpipe/sp_quad.c            |  5 ++
 src/mesa/pipe/softpipe/sp_quad.h            |  1 +
 src/mesa/pipe/softpipe/sp_quad_alpha_test.c | 81 +++++++++++++++++++++++++++++
 src/mesa/sources                            |  1 +
 src/mesa/state_tracker/st_atom_alphatest.c  |  2 +-
 7 files changed, 91 insertions(+), 2 deletions(-)
 create mode 100644 src/mesa/pipe/softpipe/sp_quad_alpha_test.c

diff --git a/src/mesa/pipe/p_state.h b/src/mesa/pipe/p_state.h
index b60e266..8e68fac 100644
--- a/src/mesa/pipe/p_state.h
+++ b/src/mesa/pipe/p_state.h
@@ -108,7 +108,7 @@ struct pipe_depth_state
 };
 
 struct pipe_alpha_test_state {
-   GLuint enable:1;
+   GLuint enabled:1;
    GLuint func:3;    /**< PIPE_FUNC_x */
    GLfloat ref;      /**< reference value */
 };
diff --git a/src/mesa/pipe/softpipe/sp_context.h b/src/mesa/pipe/softpipe/sp_context.h
index d01fc38..329544e 100644
--- a/src/mesa/pipe/softpipe/sp_context.h
+++ b/src/mesa/pipe/softpipe/sp_context.h
@@ -138,6 +138,7 @@ struct softpipe_context {
     */
    struct {
       struct quad_stage *shade;
+      struct quad_stage *alpha_test;
       struct quad_stage *depth_test;
       struct quad_stage *blend;
       struct quad_stage *output;
diff --git a/src/mesa/pipe/softpipe/sp_quad.c b/src/mesa/pipe/softpipe/sp_quad.c
index 32085ab..63126a4 100644
--- a/src/mesa/pipe/softpipe/sp_quad.c
+++ b/src/mesa/pipe/softpipe/sp_quad.c
@@ -21,6 +21,11 @@ sp_build_quad_pipeline(struct softpipe_context *sp)
       sp->quad.first = sp->quad.depth_test;
    }
 
+   if (sp->alpha_test.enabled) {
+      sp->quad.alpha_test->next = sp->quad.first;
+      sp->quad.first = sp->quad.alpha_test;
+   }
+
    /* XXX always enable shader? */
    if (1) {
       sp->quad.shade->next = sp->quad.first;
diff --git a/src/mesa/pipe/softpipe/sp_quad.h b/src/mesa/pipe/softpipe/sp_quad.h
index 86c1718..351cd4d 100644
--- a/src/mesa/pipe/softpipe/sp_quad.h
+++ b/src/mesa/pipe/softpipe/sp_quad.h
@@ -46,6 +46,7 @@ struct quad_stage {
 
 
 struct quad_stage *sp_quad_shade_stage( struct softpipe_context *softpipe );
+struct quad_stage *sp_quad_alpha_test_stage( struct softpipe_context *softpipe );
 struct quad_stage *sp_quad_depth_test_stage( struct softpipe_context *softpipe );
 struct quad_stage *sp_quad_blend_stage( struct softpipe_context *softpipe );
 struct quad_stage *sp_quad_output_stage( struct softpipe_context *softpipe );
diff --git a/src/mesa/pipe/softpipe/sp_quad_alpha_test.c b/src/mesa/pipe/softpipe/sp_quad_alpha_test.c
new file mode 100644
index 0000000..f7cebca
--- /dev/null
+++ b/src/mesa/pipe/softpipe/sp_quad_alpha_test.c
@@ -0,0 +1,81 @@
+
+/**
+ * quad alpha test
+ */
+
+#include "glheader.h"
+#include "imports.h"
+#include "sp_context.h"
+#include "sp_headers.h"
+#include "sp_quad.h"
+#include "pipe/p_defines.h"
+
+
+static void
+alpha_test_quad(struct quad_stage *qs, struct quad_header *quad)
+{
+   struct softpipe_context *softpipe = qs->softpipe;
+   GLuint j;
+   struct softpipe_surface *sps = softpipe_surface(softpipe->framebuffer.zbuf);
+   const GLfloat ref = softpipe->alpha_test.ref;
+
+#if 0
+   assert(sps); /* shouldn't get here if there's no zbuffer */
+#else
+   if (!sps)
+      return;
+#endif
+
+   switch (softpipe->alpha_test.func) {
+   case PIPE_FUNC_NEVER:
+      quad->mask = 0x0;
+      break;
+   case PIPE_FUNC_LESS:
+      for (j = 0; j < QUAD_SIZE; j++) {
+         if (quad->mask & (1 << j)) {
+            if (quad->outputs.color[3][j] >= ref) {
+               /* fail */
+               quad->mask &= (1 << j);
+            }
+         }
+      }
+      break;
+   case PIPE_FUNC_EQUAL:
+      for (j = 0; j < QUAD_SIZE; j++) {
+         if (quad->mask & (1 << j)) {
+            if (quad->outputs.color[3][j] != ref) {
+               /* fail */
+               quad->mask &= (1 << j);
+            }
+         }
+      }
+      break;
+   case PIPE_FUNC_LEQUAL:
+      for (j = 0; j < QUAD_SIZE; j++) {
+         if (quad->mask & (1 << j)) {
+            if (quad->outputs.color[3][j] > ref) {
+               /* fail */
+               quad->mask &= (1 << j);
+            }
+         }
+      }
+      break;
+      /* XXX fill in remaining cases */
+   default:
+      abort();
+   }
+
+   qs->next->run(qs->next, quad);
+}
+
+
+struct quad_stage *
+sp_quad_alpha_test_stage( struct softpipe_context *softpipe )
+{
+   struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
+
+   stage->softpipe = softpipe;
+   stage->run = alpha_test_quad;
+
+   return stage;
+}
diff --git a/src/mesa/sources b/src/mesa/sources
index 36317f8..fd84ed5 100644
--- a/src/mesa/sources
+++ b/src/mesa/sources
@@ -166,6 +166,7 @@ SOFTPIPE_SOURCES = \
 	pipe/softpipe/sp_prim_twoside.c \
 	pipe/softpipe/sp_prim_unfilled.c \
 	pipe/softpipe/sp_quad.c \
+	pipe/softpipe/sp_quad_alpha_test.c \
 	pipe/softpipe/sp_quad_blend.c \
 	pipe/softpipe/sp_quad_depth_test.c \
 	pipe/softpipe/sp_quad_fs.c \
diff --git a/src/mesa/state_tracker/st_atom_alphatest.c b/src/mesa/state_tracker/st_atom_alphatest.c
index b7cc0d7..1e2e449 100644
--- a/src/mesa/state_tracker/st_atom_alphatest.c
+++ b/src/mesa/state_tracker/st_atom_alphatest.c
@@ -67,7 +67,7 @@ update_alpha_test( struct st_context *st )
    memset(&alpha, 0, sizeof(alpha));
 
    if (st->ctx->Color.AlphaEnabled) {
-      alpha.enable = 1;
+      alpha.enabled = 1;
       alpha.func = gl_alpha_func_to_sp(st->ctx->Color.AlphaFunc);
       alpha.ref = st->ctx->Color.AlphaRef;
    }
-- 
2.7.4