st/mesa: add PIPE_CAP_GLSL_FEATURE_LEVEL, cleanup st_extensions.c

v2: handle the cap in r300 and r600 as well

Additional info for r600g:
   The env var R600_GLSL130=1 enables GLSL 1.3.
   Along with R600_STREAMOUT=1, it enables full GL 3.

6 files changed, 41 insertions, 22 deletions

diff --git a/src/gallium/docs/source/screen.rst b/src/gallium/docs/source/screen.rst
index 8161c64253d..2af9f74e902 100644
--- a/src/gallium/docs/source/screen.rst
+++ b/src/gallium/docs/source/screen.rst
@@ -96,2 +96,5 @@ The integer capabilities:
   controlled through pipe_rasterizer_state.
+* ``PIPE_CAP_GLSL_FEATURE_LEVEL``: Whether the driver supports features
+  equivalent to a specific GLSL version. E.g. for GLSL 1.3, report 130.
+
 
diff --git a/src/gallium/drivers/r300/r300_screen.c b/src/gallium/drivers/r300/r300_screen.c
index 48a65696359..9a9418bc927 100644
--- a/src/gallium/drivers/r300/r300_screen.c
+++ b/src/gallium/drivers/r300/r300_screen.c
@@ -107,2 +107,5 @@ static int r300_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 
+        case PIPE_CAP_GLSL_FEATURE_LEVEL:
+            return 120;
+
         /* r300 cannot do swizzling of compressed textures. Supported otherwise. */
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index c38fbc59c5a..1123557a5ec 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -369,2 +369,5 @@ static int r600_get_param(struct pipe_screen* pscreen, enum pipe_cap param)
 
+	case PIPE_CAP_GLSL_FEATURE_LEVEL:
+		return debug_get_bool_option("R600_GLSL130", FALSE) ? 130 : 120;
+
 	/* Supported except the original R600. */
diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index 37bbc43f325..6cafeafbe19 100644
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -134,2 +134,4 @@ softpipe_get_param(struct pipe_screen *screen, enum pipe_cap param)
       return 1;
+   case PIPE_CAP_GLSL_FEATURE_LEVEL:
+      return 130;
    default:
diff --git a/src/gallium/include/pipe/p_defines.h b/src/gallium/include/pipe/p_defines.h
index 2cd11f988ab..000be3d86cf 100644
--- a/src/gallium/include/pipe/p_defines.h
+++ b/src/gallium/include/pipe/p_defines.h
@@ -489,3 +489,4 @@ enum pipe_cap {
    PIPE_CAP_VERTEX_COLOR_UNCLAMPED = 60,
-   PIPE_CAP_VERTEX_COLOR_CLAMPED = 61
+   PIPE_CAP_VERTEX_COLOR_CLAMPED = 61,
+   PIPE_CAP_GLSL_FEATURE_LEVEL = 62,
 };
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 49709d34260..f8b9ff879eb 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -260,6 +260,3 @@ void st_init_extensions(struct st_context *st)
    struct gl_context *ctx = st->ctx;
-   int i;
-
-   ctx->Const.GLSLVersion = 120;
-   _mesa_override_glsl_version(st->ctx);
+   int i, glsl_feature_level;
 
@@ -332,2 +329,29 @@ void st_init_extensions(struct st_context *st)
 
+   /* Figure out GLSL support. */
+   glsl_feature_level = screen->get_param(screen, PIPE_CAP_GLSL_FEATURE_LEVEL);
+
+   if (glsl_feature_level >= 130) {
+      ctx->Const.GLSLVersion = 130;
+   } else {
+      ctx->Const.GLSLVersion = 120;
+   }
+
+   _mesa_override_glsl_version(st->ctx);
+
+   if (ctx->Const.GLSLVersion >= 130) {
+      ctx->Const.NativeIntegers = GL_TRUE;
+      ctx->Const.MaxClipPlanes = 8;
+
+      /* Extensions that only depend on GLSL 1.3. */
+      ctx->Extensions.ARB_conservative_depth = GL_TRUE;
+   } else {
+      /* Optional integer support for GLSL 1.2. */
+      if (screen->get_shader_param(screen, PIPE_SHADER_VERTEX,
+                                   PIPE_SHADER_CAP_INTEGERS) &&
+          screen->get_shader_param(screen, PIPE_SHADER_FRAGMENT,
+                                   PIPE_SHADER_CAP_INTEGERS)) {
+         ctx->Const.NativeIntegers = GL_TRUE;
+      }
+   }
+
    /*
@@ -580,19 +604,2 @@ void st_init_extensions(struct st_context *st)
 
-   if (screen->get_shader_param(screen, PIPE_SHADER_VERTEX,
-                                PIPE_SHADER_CAP_INTEGERS) &&
-       screen->get_shader_param(screen, PIPE_SHADER_FRAGMENT,
-                                PIPE_SHADER_CAP_INTEGERS)) {
-      ctx->Const.NativeIntegers = GL_TRUE;
-   }
-
-   if (ctx->Const.NativeIntegers)
-      ctx->Const.GLSLVersion = 130;
-
-   /* Extensions that only depend on the GLSL version:
-    */
-   if (ctx->Const.GLSLVersion >= 130) {
-      ctx->Extensions.ARB_conservative_depth = GL_TRUE;
-      ctx->Const.MaxClipPlanes = 8;
-   }
-
    ctx->Extensions.NV_primitive_restart = GL_TRUE;