gallium: add st_api feature mask to prevent advertising MS visuals

v2: use a define for the maximum sample count
v3: also test odd sample counts (r300 supports MS3)

While multisample renderbuffers are supported by mesa, MS visuals
are not, so we need a way to tell dri/st not to advertise them even
if the gallium driver does support multisampled surfaces.

Otherwise applications selecting these non-functional visuals would
run into trouble ...

Reviewed-by: Brian Paul <[email protected]>

3 files changed, 36 insertions, 12 deletions

diff --git a/src/gallium/include/state_tracker/st_api.h b/src/gallium/include/state_tracker/st_api.h
index 3af1dfc6d4d..86ab02d2883 100644
--- a/src/gallium/include/state_tracker/st_api.h
+++ b/src/gallium/include/state_tracker/st_api.h
@@ -70,6 +70,17 @@ enum st_profile_type
 #define ST_PROFILE_OPENGL_ES2_MASK   (1 << ST_PROFILE_OPENGL_ES2)
 
 /**
+ * Optional API/state tracker features.
+ */
+enum st_api_feature
+{
+   ST_API_FEATURE_MS_VISUALS  /**< support for multisample visuals */
+};
+
+/* for feature_mask in st_api */
+#define ST_API_FEATURE_MS_VISUALS_MASK (1 << ST_API_FEATURE_MS_VISUALS)
+
+/**
  * New context flags for GL 3.0 and beyond.
  *
  * Profile information (core vs. compatibilty for OpenGL 3.2+) is communicated
@@ -430,6 +441,11 @@ struct st_api
    unsigned profile_mask;
 
    /**
+    * The supported optional features.  Tested with ST_FEATURE_*_MASK.
+    */
+   unsigned feature_mask;
+
+   /**
     * Destroy the API.
     */
    void (*destroy)(struct st_api *stapi);
diff --git a/src/gallium/state_trackers/dri/common/dri_screen.c b/src/gallium/state_trackers/dri/common/dri_screen.c
index 24efbde2017..406e550e58e 100644
--- a/src/gallium/state_trackers/dri/common/dri_screen.c
+++ b/src/gallium/state_trackers/dri/common/dri_screen.c
@@ -41,6 +41,8 @@
 
 #include "util/u_debug.h"
 
+#define MSAA_VISUAL_MAX_SAMPLES 8
+
 PUBLIC const char __driConfigOptions[] =
    DRI_CONF_BEGIN
       DRI_CONF_SECTION_PERFORMANCE
@@ -72,10 +74,10 @@ dri_fill_in_modes(struct dri_screen *screen,
    __DRIconfig **configs_x8r8g8b8 = NULL;
    uint8_t depth_bits_array[5];
    uint8_t stencil_bits_array[5];
-   uint8_t msaa_samples_array[5];
+   uint8_t msaa_samples_array[MSAA_VISUAL_MAX_SAMPLES];
    unsigned depth_buffer_factor;
    unsigned back_buffer_factor;
-   unsigned msaa_samples_factor;
+   unsigned msaa_samples_factor, msaa_samples_max;
    unsigned i;
    struct pipe_screen *p_screen = screen->base.screen;
    boolean pf_r5g6b5, pf_a8r8g8b8, pf_x8r8g8b8;
@@ -89,6 +91,9 @@ dri_fill_in_modes(struct dri_screen *screen,
    stencil_bits_array[0] = 0;
    depth_buffer_factor = 1;
 
+   msaa_samples_max = (screen->st_api->feature_mask & ST_API_FEATURE_MS_VISUALS)
+      ? MSAA_VISUAL_MAX_SAMPLES : 1;
+
    pf_x8z24 = p_screen->is_format_supported(p_screen, PIPE_FORMAT_Z24X8_UNORM,
 					    PIPE_TEXTURE_2D, 0,
                                             PIPE_BIND_DEPTH_STENCIL);
@@ -146,14 +151,16 @@ dri_fill_in_modes(struct dri_screen *screen,
    msaa_samples_array[0] = 0;
    back_buffer_factor = 3;
 
-   /* also test color for msaa 2/4/6/8 - just assume it'll work for all depth buffers */
+   /* Also test for color multisample support - just assume it'll work
+    * for all depth buffers.
+    */
    if (pf_r5g6b5) {
       msaa_samples_factor = 1;
-      for (i = 1; i < 5; i++) {
+      for (i = 2; i <= msaa_samples_max; i++) {
          if (p_screen->is_format_supported(p_screen, PIPE_FORMAT_B5G6R5_UNORM,
-						   PIPE_TEXTURE_2D, i*2,
+						   PIPE_TEXTURE_2D, i,
                                                    PIPE_BIND_RENDER_TARGET)) {
-            msaa_samples_array[msaa_samples_factor] = i * 2;
+            msaa_samples_array[msaa_samples_factor] = i;
             msaa_samples_factor++;
          }
       }
@@ -168,11 +175,11 @@ dri_fill_in_modes(struct dri_screen *screen,
 
    if (pf_a8r8g8b8) {
       msaa_samples_factor = 1;
-      for (i = 1; i < 5; i++) {
+      for (i = 2; i <= msaa_samples_max; i++) {
          if (p_screen->is_format_supported(p_screen, PIPE_FORMAT_B8G8R8A8_UNORM,
-						   PIPE_TEXTURE_2D, i*2,
+						   PIPE_TEXTURE_2D, i,
                                                    PIPE_BIND_RENDER_TARGET)) {
-            msaa_samples_array[msaa_samples_factor] = i * 2;
+            msaa_samples_array[msaa_samples_factor] = i;
             msaa_samples_factor++;
          }
       }
@@ -190,11 +197,11 @@ dri_fill_in_modes(struct dri_screen *screen,
 
    if (pf_x8r8g8b8) {
       msaa_samples_factor = 1;
-      for (i = 1; i < 5; i++) {
+      for (i = 2; i <= msaa_samples_max; i++) {
          if (p_screen->is_format_supported(p_screen, PIPE_FORMAT_B8G8R8X8_UNORM,
-						   PIPE_TEXTURE_2D, i*2,
+						   PIPE_TEXTURE_2D, i,
                                                    PIPE_BIND_RENDER_TARGET)) {
-            msaa_samples_array[msaa_samples_factor] = i * 2;
+            msaa_samples_array[msaa_samples_factor] = i;
             msaa_samples_factor++;
          }
       }
diff --git a/src/gallium/state_trackers/vega/vg_manager.c b/src/gallium/state_trackers/vega/vg_manager.c
index e88f5f17fe5..660a7af884f 100644
--- a/src/gallium/state_trackers/vega/vg_manager.c
+++ b/src/gallium/state_trackers/vega/vg_manager.c
@@ -369,6 +369,7 @@ static const struct st_api vg_api = {
    "Vega " VEGA_VERSION_STRING,
    ST_API_OPENVG,
    ST_PROFILE_DEFAULT_MASK,
+   0,
    vg_api_destroy,
    vg_api_get_proc_address,
    vg_api_create_context,