gallium/u_tests: test a NULL constant buffer

This expects (0,0,0,0), though it can be changed to something else or allow
more than one set of values to be considered correct.

This is currently the radeonsi behavior.

Reviewed-by: Glenn Kennard <glenn.kennard@gmail.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_tests.c b/src/gallium/auxiliary/util/u_tests.c
index 10111539c78..5257b548c51 100644
--- a/src/gallium/auxiliary/util/u_tests.c
+++ b/src/gallium/auxiliary/util/u_tests.c
@@ -30,9 +30,11 @@
 #include "util/u_draw_quad.h"
 #include "util/u_format.h"
 #include "util/u_inlines.h"
+#include "util/u_memory.h"
 #include "util/u_simple_shaders.h"
 #include "util/u_surface.h"
 #include "util/u_tile.h"
+#include "tgsi/tgsi_text.h"
 #include "cso_cache/cso_context.h"
 #include <stdio.h>
 
@@ -371,6 +373,60 @@ null_sampler_view(struct pipe_context *ctx)
    util_report_result(pass);
 }
 
+static void
+null_constant_buffer(struct pipe_context *ctx)
+{
+   struct cso_context *cso;
+   struct pipe_resource *cb;
+   void *fs, *vs;
+   bool pass = true;
+   static const float zero[] = {0, 0, 0, 0};
+
+   cso = cso_create_context(ctx);
+   cb = util_create_texture2d(ctx->screen, 256, 256,
+                              PIPE_FORMAT_R8G8B8A8_UNORM);
+   util_set_common_states_and_clear(cso, ctx, cb);
+
+   ctx->set_constant_buffer(ctx, PIPE_SHADER_FRAGMENT, 0, NULL);
+
+   /* Fragment shader. */
+   {
+      static const char *text = /* I don't like ureg... */
+            "FRAG\n"
+            "DCL CONST[0]\n"
+            "DCL OUT[0], COLOR\n"
+
+            "MOV OUT[0], CONST[0]\n"
+            "END\n";
+      struct tgsi_token tokens[1000];
+      struct pipe_shader_state state = {tokens};
+
+      if (!tgsi_text_translate(text, tokens, Elements(tokens))) {
+         puts("Can't compile a fragment shader.");
+         util_report_result(FAIL);
+         return;
+      }
+      fs = ctx->create_fs_state(ctx, &state);
+      cso_set_fragment_shader_handle(cso, fs);
+   }
+
+   /* Vertex shader. */
+   vs = util_set_passthrough_vertex_shader(cso, ctx, false);
+   util_draw_fullscreen_quad(cso);
+
+   /* Probe pixels. */
+   pass = pass && util_probe_rect_rgba(ctx, cb, 0, 0, cb->width0,
+                                       cb->height0, zero);
+
+   /* Cleanup. */
+   cso_destroy_context(cso);
+   ctx->delete_vs_state(ctx, vs);
+   ctx->delete_fs_state(ctx, fs);
+   pipe_resource_reference(&cb, NULL);
+
+   util_report_result(pass);
+}
+
 /**
  * Run all tests. This should be run with a clean context after
  * context_create.
@@ -382,6 +438,7 @@ util_run_tests(struct pipe_screen *screen)
 
    tgsi_vs_window_space_position(ctx);
    null_sampler_view(ctx);
+   null_constant_buffer(ctx);
 
    ctx->destroy(ctx);