st_api: Remove st_context::is_visual_supported.

The callback is used by st/vega to check if a visual specifies the
depth/stencil format.  It forces st/vega to be loaded by st/egl to
perform the check.  As noted in EGL spec, the depth/stencil format of a
visual should not affect OpenVG.  It should be better to ignore the
field and always allocate the depth/stencil texture.

src/gallium/include/state_tracker/st_api.h

@@ -368,12 +368,6 @@ struct st_api
     */
    st_proc_t (*get_proc_address)(struct st_api *stapi, const char *procname);
 
-   /**
-    * Return true if the visual is supported by the state tracker.
-    */
-   boolean (*is_visual_supported)(struct st_api *stapi,
-                                  const struct st_visual *visual);
-
    /**
     * Create a rendering context.
     */

src/gallium/state_trackers/egl/common/egl_g3d.c

@@ -272,7 +272,6 @@ egl_g3d_init_config(_EGLDriver *drv, _EGLDisplay *dpy,
    struct egl_g3d_config *gconf = egl_g3d_config(conf);
    EGLint buffer_mask, api_mask;
    EGLBoolean valid;
-   EGLint i;
 
    buffer_mask = 0x0;
    if (nconf->buffer_mask & (1 << NATIVE_ATTACHMENT_FRONT_LEFT))
@@ -293,14 +292,7 @@ egl_g3d_init_config(_EGLDriver *drv, _EGLDisplay *dpy,
    gconf->stvis.render_buffer = (buffer_mask & ST_ATTACHMENT_BACK_LEFT_MASK) ?
       ST_ATTACHMENT_BACK_LEFT : ST_ATTACHMENT_FRONT_LEFT;
 
-   api_mask = 0;
-   for (i = 0; i < ST_API_COUNT; i++) {
-      struct st_api *stapi = gdrv->stapis[i];
-      if (stapi) {
-         if (stapi->is_visual_supported(stapi, &gconf->stvis))
-            api_mask |= egl_g3d_st_api_bit(i);
-      }
-   }
+   api_mask = gdrv->api_mask;;
    /* this is required by EGL, not by OpenGL ES */
    if (nconf->window_bit &&
        gconf->stvis.render_buffer != ST_ATTACHMENT_BACK_LEFT)

src/gallium/state_trackers/vega/vg_context.c

@@ -65,6 +65,32 @@ static void init_clear(struct vg_context *st)
    st->clear.fs =
       util_make_fragment_passthrough_shader(pipe);
 }
+
+/**
+ * A depth/stencil rb will be needed regardless of what the visual says.
+ */
+static boolean
+choose_depth_stencil_format(struct vg_context *ctx)
+{
+   struct pipe_screen *screen = ctx->pipe->screen;
+   enum pipe_format formats[] = {
+      PIPE_FORMAT_Z24_UNORM_S8_USCALED,
+      PIPE_FORMAT_S8_USCALED_Z24_UNORM,
+      PIPE_FORMAT_NONE
+   };
+   enum pipe_format *fmt;
+
+   for (fmt = formats; *fmt != PIPE_FORMAT_NONE; fmt++) {
+      if (screen->is_format_supported(screen, *fmt,
+               PIPE_TEXTURE_2D, 0, PIPE_BIND_DEPTH_STENCIL, 0))
+         break;
+   }
+
+   ctx->ds_format = *fmt;
+
+   return (ctx->ds_format != PIPE_FORMAT_NONE);
+}
+
 void vg_set_current_context(struct vg_context *ctx)
 {
    _vg_context = ctx;
@@ -81,6 +107,10 @@ struct vg_context * vg_create_context(struct pipe_context *pipe,
    ctx = CALLOC_STRUCT(vg_context);
 
    ctx->pipe = pipe;
+   if (!choose_depth_stencil_format(ctx)) {
+      FREE(ctx);
+      return NULL;
+   }
 
    ctx->dispatch = api_create_dispatch();
 

src/gallium/state_trackers/vega/vg_context.h

@@ -94,6 +94,7 @@ struct vg_context
    struct mapi_table *dispatch;
 
    struct pipe_context *pipe;
+   enum pipe_format ds_format;
 
    struct {
       struct vg_state vg;

src/gallium/state_trackers/vega/vg_manager.c

@@ -448,8 +448,7 @@ vg_context_bind_framebuffers(struct st_context_iface *stctxi,
       /* free the existing fb */
       if (!stdrawi ||
           stfb->strb_att != strb_att ||
-          stfb->strb->format != stdrawi->visual->color_format ||
-          stfb->dsrb->format != stdrawi->visual->depth_stencil_format) {
+          stfb->strb->format != stdrawi->visual->color_format) {
          destroy_renderbuffer(stfb->strb);
          destroy_renderbuffer(stfb->dsrb);
          free(stfb);
@@ -476,7 +475,7 @@ vg_context_bind_framebuffers(struct st_context_iface *stctxi,
          return FALSE;
       }
 
-      stfb->dsrb = create_renderbuffer(stdrawi->visual->depth_stencil_format);
+      stfb->dsrb = create_renderbuffer(ctx->ds_format);
       if (!stfb->dsrb) {
          free(stfb->strb);
          free(stfb);
@@ -517,14 +516,6 @@ vg_api_get_current(struct st_api *stapi)
    return (ctx) ? &ctx->iface : NULL;
 }
 
-static boolean
-vg_api_is_visual_supported(struct st_api *stapi,
-                           const struct st_visual *visual)
-{
-   /* the impl requires a depth/stencil buffer */
-   return util_format_is_depth_and_stencil(visual->depth_stencil_format);
-}
-
 static st_proc_t
 vg_api_get_proc_address(struct st_api *stapi, const char *procname)
 {
@@ -539,7 +530,6 @@ vg_api_destroy(struct st_api *stapi)
 static const struct st_api vg_api = {
    vg_api_destroy,
    vg_api_get_proc_address,
-   vg_api_is_visual_supported,
    vg_api_create_context,
    vg_api_make_current,
    vg_api_get_current,

src/mesa/state_tracker/st_manager.c

@@ -707,13 +707,6 @@ st_api_get_current(struct st_api *stapi)
    return (st) ? &st->iface : NULL;
 }
 
-static boolean
-st_api_is_visual_supported(struct st_api *stapi,
-                           const struct st_visual *visual)
-{
-   return TRUE;
-}
-
 static st_proc_t
 st_api_get_proc_address(struct st_api *stapi, const char *procname)
 {
@@ -822,7 +815,6 @@ st_manager_add_color_renderbuffer(struct st_context *st, GLframebuffer *fb,
 struct st_api st_gl_api = {
    st_api_destroy,
    st_api_get_proc_address,
-   st_api_is_visual_supported,
    st_api_create_context,
    st_api_make_current,
    st_api_get_current,