[Mesa-dev] [PATCH 1/3] mesa: Disallow deprecated SNORM formats for renderbuffers

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

The OpenGL 3.2 core profile spec says:

    "The following base internal formats from table 3.11 are
    color-renderable: RED, RG, RGB, and RGBA. The sized internal formats
    from table 3.12 that have a color-renderable base internal format
    are also color-renderable. No other formats, including compressed
    internal formats, are color-renderable."

The OpenGL 3.2 compatibility profile spec says (only ALPHA is added):

    "The following base internal formats from table 3.16 are
    color-renderable: ALPHA, RED, RG, RGB, and RGBA. The sized internal formats
    from table 3.17 that have a color-renderable base internal format
    are also color-renderable. No other formats, including compressed
    internal formats, are color-renderable."

Table 3.12 in the core profile spec and table 3.17 in the compatibility
profile spec list SNORM formats as having a base internal format of RED,
RG, RGB, or RGBA.  From this we infer that they should also be color
renderable.

The OpenGL ES 3.0 spec says:

    "An internal format is color-renderable if it is one of the formats
    from table 3.12 noted as color-renderable or if it is unsized format
    RGBA or RGB. No other formats, including compressed internal
    formats, are color-renderable."

In the OpenGL ES 3.0 spec, none of the SNORM formats have "color-
renderable" marked in table 3.12.  The RGB I and UI formats also are not
color-renderable in ES3, but we'll save that change for another patch.

As a data point, NVIDIA's closed-source driver (version 304.64) rejects
*all* SNORM formats for renderbuffers in an OpenGL 4.x compatibility
profile.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: Matt Turner <mattst88 at gmail.com>
Cc: Marek Olšák <maraeo at gmail.com>
---
 src/mesa/main/fbobject.c | 38 ++++----------------------------------
 1 file changed, 4 insertions(+), 34 deletions(-)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index ce77b9f..ab53bac 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -1169,35 +1169,23 @@ _mesa_base_fbo_format(struct gl_context *ctx, GLenum internalFormat)
       return ctx->API != API_OPENGLES && ctx->Extensions.ARB_texture_rg
          ? GL_RG : 0;
    /* signed normalized texture formats */
-   case GL_R8_SNORM:
-      return ctx->Version >= 30
-         || (ctx->API == API_OPENGL_COMPAT && ctx->Extensions.EXT_texture_snorm)
-         ? GL_RED : 0;
    case GL_RED_SNORM:
+   case GL_R8_SNORM:
    case GL_R16_SNORM:
       return _mesa_is_desktop_gl(ctx) && ctx->Extensions.EXT_texture_snorm
          ? GL_RED : 0;
-   case GL_RG8_SNORM:
-      return ctx->Version >= 30
-         || (ctx->API == API_OPENGL_COMPAT && ctx->Extensions.EXT_texture_snorm)
-         ? GL_RG : 0;
    case GL_RG_SNORM:
+   case GL_RG8_SNORM:
    case GL_RG16_SNORM:
       return _mesa_is_desktop_gl(ctx) && ctx->Extensions.EXT_texture_snorm
          ? GL_RG : 0;
-   case GL_RGB8_SNORM:
-      return ctx->Version >= 30
-         || (ctx->API == API_OPENGL_COMPAT && ctx->Extensions.EXT_texture_snorm)
-         ? GL_RGB : 0;
    case GL_RGB_SNORM:
+   case GL_RGB8_SNORM:
    case GL_RGB16_SNORM:
       return _mesa_is_desktop_gl(ctx) && ctx->Extensions.EXT_texture_snorm
          ? GL_RGB : 0;
-   case GL_RGBA8_SNORM:
-      return ctx->Version >= 30
-         || (ctx->API == API_OPENGL_COMPAT && ctx->Extensions.EXT_texture_snorm)
-         ? GL_RGBA : 0;
    case GL_RGBA_SNORM:
+   case GL_RGBA8_SNORM:
    case GL_RGBA16_SNORM:
       return _mesa_is_desktop_gl(ctx) && ctx->Extensions.EXT_texture_snorm
          ? GL_RGBA : 0;
@@ -1207,24 +1195,6 @@ _mesa_base_fbo_format(struct gl_context *ctx, GLenum internalFormat)
       return ctx->API == API_OPENGL_COMPAT &&
              ctx->Extensions.EXT_texture_snorm &&
              ctx->Extensions.ARB_framebuffer_object ? GL_ALPHA : 0;
-   case GL_LUMINANCE_SNORM:
-   case GL_LUMINANCE8_SNORM:
-   case GL_LUMINANCE16_SNORM:
-      return ctx->API == API_OPENGL_COMPAT &&
-             ctx->Extensions.EXT_texture_snorm &&
-             ctx->Extensions.ARB_framebuffer_object ? GL_LUMINANCE : 0;
-   case GL_LUMINANCE_ALPHA_SNORM:
-   case GL_LUMINANCE8_ALPHA8_SNORM:
-   case GL_LUMINANCE16_ALPHA16_SNORM:
-      return ctx->API == API_OPENGL_COMPAT &&
-             ctx->Extensions.EXT_texture_snorm &&
-             ctx->Extensions.ARB_framebuffer_object ? GL_LUMINANCE_ALPHA : 0;
-   case GL_INTENSITY_SNORM:
-   case GL_INTENSITY8_SNORM:
-   case GL_INTENSITY16_SNORM:
-      return ctx->API == API_OPENGL_COMPAT &&
-             ctx->Extensions.EXT_texture_snorm &&
-             ctx->Extensions.ARB_framebuffer_object ? GL_INTENSITY : 0;
    case GL_R16F:
    case GL_R32F:
       return ctx->Version >= 30
-- 
1.7.11.7