mesa: check driver format support for certain GetInternalformativ queries

according to spec, these should return NONE if the format is
not supported for a given texture target, but mesa was incorrectly
returning a hardcoded value for all cases without checking the driver

instead, check whether the driver can create a texture for a given
format to correctly handle this non-support case

cc: mesa-stable

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27621>
(cherry picked from commit 893780b362)

.pick_status.json

@@ -2754,7 +2754,7 @@
         "description": "mesa: check driver format support for certain GetInternalformativ queries",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null

src/mesa/main/formatquery.c

@@ -1112,6 +1112,12 @@ _mesa_GetInternalformativ(GLenum target, GLenum internalformat, GLenum pname,
       if (get_pname == 0)
          goto end;
 
+      /* if the resource is unsupported, zero is returned */
+      if (!st_QueryTextureFormatSupport(ctx, target, internalformat)) {
+         buffer[0] = 0;
+         break;
+      }
+
       _mesa_GetIntegerv(get_pname, buffer);
       break;
    }
@@ -1123,6 +1129,12 @@ _mesa_GetInternalformativ(GLenum target, GLenum internalformat, GLenum pname,
       if (!_mesa_is_array_texture(target))
          goto end;
 
+      /* if the resource is unsupported, zero is returned */
+      if (!st_QueryTextureFormatSupport(ctx, target, internalformat)) {
+         buffer[0] = 0;
+         break;
+      }
+
       _mesa_GetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS, buffer);
       break;
 
@@ -1137,6 +1149,12 @@ _mesa_GetInternalformativ(GLenum target, GLenum internalformat, GLenum pname,
       unsigned i;
       GLint current_value;
 
+      /* if the resource is unsupported, zero is returned */
+      if (!st_QueryTextureFormatSupport(ctx, target, internalformat)) {
+         buffer[0] = 0;
+         break;
+      }
+
       /* Combining the dimensions. Note that for array targets, this would
        * automatically include the value of MAX_LAYERS, as that value is
        * returned as MAX_HEIGHT or MAX_DEPTH */
@@ -1515,6 +1533,14 @@ _mesa_GetInternalformativ(GLenum target, GLenum internalformat, GLenum pname,
       if (targetIndex < 0 || targetIndex == TEXTURE_BUFFER_INDEX)
          goto end;
 
+      /* If the resource is not supported for image textures,
+       * or if image textures are not supported, NONE is returned.
+       */
+      if (!st_QueryTextureFormatSupport(ctx, target, internalformat)) {
+         buffer[0] = GL_NONE;
+         break;
+      }
+
       /* From spec: "Equivalent to calling GetTexParameter with <value> set
        * to IMAGE_FORMAT_COMPATIBILITY_TYPE."
        *

src/mesa/state_tracker/st_format.c

@@ -1507,6 +1507,49 @@ st_QuerySamplesForFormat(struct gl_context *ctx, GLenum target,
    return num_sample_counts;
 }
 
+/* check whether any texture can be allocated for a given format */
+bool
+st_QueryTextureFormatSupport(struct gl_context *ctx, GLenum target, GLenum internalFormat)
+{
+   struct st_context *st = st_context(ctx);
+
+   /* If an sRGB framebuffer is unsupported, sRGB formats behave like linear
+    * formats.
+    */
+   if (!ctx->Extensions.EXT_sRGB) {
+      internalFormat = _mesa_get_linear_internalformat(internalFormat);
+   }
+
+   /* multisample textures need >= 2 samples */
+   unsigned min_samples = target == GL_TEXTURE_2D_MULTISAMPLE ||
+                          target == GL_TEXTURE_2D_MULTISAMPLE_ARRAY ? 1 : 0;
+   unsigned max_samples = min_samples ? 16 : 1;
+
+   /* compressed textures will be allocated as e.g., RGBA8, so check that instead */
+   enum pipe_format pf = st_choose_format(st, internalFormat, GL_NONE, GL_NONE,
+                                          PIPE_TEXTURE_2D, 0, 0, 0,
+                                          false, false);
+   if (util_format_is_compressed(pf)) {
+      enum pipe_format fmts[2] = {0};
+      pf = st_mesa_format_to_pipe_format(st, st_pipe_format_to_mesa_format(pf));
+      fmts[0] = pf;
+      for (unsigned i = max_samples; i > min_samples; i >>= 1) {
+         if (find_supported_format(st->screen, fmts, PIPE_TEXTURE_2D,
+                                   i, i, PIPE_BIND_SAMPLER_VIEW, false))
+            return true;
+      }
+      return false;
+   }
+   for (unsigned i = max_samples; i > min_samples; i >>= 1) {
+      if (st_choose_format(st, internalFormat, GL_NONE, GL_NONE,
+                           PIPE_TEXTURE_2D, i, i, PIPE_BIND_SAMPLER_VIEW,
+                           false, false))
+         return true;
+   }
+
+   return false;
+}
+
 
 /**
  * ARB_internalformat_query2 driver hook.

src/mesa/state_tracker/st_format.h

@@ -70,7 +70,8 @@ extern mesa_format
 st_ChooseTextureFormat(struct gl_context * ctx, GLenum target,
                        GLint internalFormat,
                        GLenum format, GLenum type);
-
+bool
+st_QueryTextureFormatSupport(struct gl_context *ctx, GLenum target, GLenum internalFormat);
 void
 st_QueryInternalFormat(struct gl_context *ctx, GLenum target,
                        GLenum internalFormat, GLenum pname, GLint *params);