[Mesa-dev] [PATCH 3/3] mesa: use _mesa_check_sample_count() for multisample textures

[Chris Forbes]

Extends _mesa_check_sample_count() to properly support the
TEXTURE_2D_MULTISAMPLE and TEXTURE_2D_MULTISAMPLE_ARRAY targets, which
have subtly different limits than renderbuffers:

The ARB_texture_multisample spec (or GL3.2) says, when describing the
operation of TexImage*DMultisample:

   "The error INVALID_OPERATION may be generated if any of the following
   are true:

   * <internalformat> is a depth/stencil-renderable format and <samples>
     is greater than the value of MAX_DEPTH_TEXTURE_SAMPLES
   * <internalformat> is a color-renderable format and <samples> is
     greater than the value of MAX_COLOR_TEXTURE_SAMPLES
   * <internalformat> is a signed or unsigned integer format and
     <samples> is greater than the value of MAX_INTEGER_SAMPLES"

   And additionally, slightly later:

   "... or if <samples> is greater than MAX_SAMPLES, then the error
   INVALID_VALUE is generated."

If ARB_internalformat_query (or GL4.2) is supported, all of these limits
are replaced by:

   "The error INVALID_OPERATION will be generated if <samples> is
   greater than the maximum number of samples supported for this
   <target> and <internalformat>, which can be determined by calling
   GetInternalformativ with a <pname> of SAMPLES (see section 6.X)."

This resolves the remaining TODO in the implementation of
TexImage*DMultisample.

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
---
 src/mesa/main/fbobject.c | 11 +++++++++++
 src/mesa/main/teximage.c | 30 +++++-------------------------
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index 50339c2..208cf0d 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -1471,6 +1471,17 @@ _mesa_check_sample_count(struct gl_context *ctx, GLenum target,
    if (ctx->Extensions.ARB_texture_multisample) {
       if (_mesa_is_enum_format_integer(internalFormat))
          return samples > ctx->Const.MaxIntegerSamples ? GL_INVALID_OPERATION : GL_NO_ERROR;
+
+      if (target == GL_TEXTURE_2D_MULTISAMPLE ||
+          target == GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
+
+         if (_mesa_is_depth_or_stencil_format(internalFormat))
+            return samples > ctx->Const.MaxDepthTextureSamples
+               ? GL_INVALID_OPERATION : GL_NO_ERROR;
+         else
+            return samples > ctx->Const.MaxColorTextureSamples
+               ? GL_INVALID_OPERATION : GL_NO_ERROR;
+      }
    }
 
    /* No more specific limit is available, so just use MAX_SAMPLES */
diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index dc9543f..edf0a4c 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -4216,35 +4216,15 @@ teximagemultisample(GLuint dims, GLenum target, GLsizei samples,
       return;
    }
 
-   if (_mesa_is_enum_format_integer(internalformat)) {
-      if (samples > ctx->Const.MaxIntegerSamples) {
-         _mesa_error(ctx, GL_INVALID_OPERATION,
-               "glTexImage%uDMultisample(samples>GL_MAX_INTEGER_SAMPLES)",
-               dims);
-         return;
-      }
-   }
-   else if (_mesa_is_depth_or_stencil_format(internalformat)) {
-      if (samples > ctx->Const.MaxDepthTextureSamples) {
-         _mesa_error(ctx, GL_INVALID_OPERATION,
-               "glTexImage%uDMultisample(samples>GL_MAX_DEPTH_TEXTURE_SAMPLES)",
-               dims);
-         return;
-      }
-   }
-   else {
-      if (samples > ctx->Const.MaxColorTextureSamples) {
-         _mesa_error(ctx, GL_INVALID_OPERATION,
-               "glTexImage%uDMultisample(samples>GL_MAX_COLOR_TEXTURE_SAMPLES)",
-               dims);
+   {
+      GLenum sample_count_error = _mesa_check_sample_count(ctx, target,
+            internalformat, samples);
+      if (sample_count_error != GL_NO_ERROR) {
+         _mesa_error(ctx, sample_count_error, "glTexImage%uMultisample(samples)", dims);
          return;
       }
    }
 
-   /* TODO: should ask the driver for the exact limit for this internalformat
-    * once IDR's internalformat_query bits land
-    */
-
    texObj = _mesa_get_current_tex_object(ctx, target);
    texImage = _mesa_get_tex_image(ctx, texObj, 0, 0);
 
-- 
1.8.1.3