mesa: Add GL_TEXTURE_CUBE_MAP to _mesa_max_texture_levels(). [v2]

For cube maps, _mesa_generate_mipmap() calls this with
GL_TEXTURE_CUBE_MAP (the gl_texture_object's Target) rather than one
of the faces.  This caused _mesa_max_texture_levels() to return 0, which
resulted in maxLevels == -1 and the next line's assertion to fail.

This function is called from seven places:
- fbobject.c: framebuffer_texture()
- mipmap.c: _mesa_generate_mipmap()
- texgetimage.c:
  - getteximage_error_check()
  - getcompressedteximage_error_check()
- texparam.c: _mesa_GetTexLevelParameteriv()
- texstorage.c: tex_storage_error_check()

All of these (or their callers) now explicitly check for invalid targets
already, so this shouldn't cause invalid targets to slip through.
(Technically _mesa_generate_mipmap() doesn't check for invalid targets,
but the API-facing _mesa_GenerateMipmapEXT() function does.)

+2 oglconforms (float-texture/mipmap.automatic and mipmap.manual)

In addition to fixing the mipmap bug, it should also cause glTexStorage
to accept GL_TEXTURE_CUBE_MAP, which is explicitly allowed by the spec.

v2: Drop alterations to callers; this is now in a patch series that adds
    explicit checking to API functions.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index 569adc16a7f..9deaab2ad94 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -946,6 +946,7 @@ _mesa_max_texture_levels(struct gl_context *ctx, GLenum target)
    case GL_TEXTURE_3D:
    case GL_PROXY_TEXTURE_3D:
       return ctx->Const.Max3DTextureLevels;
+   case GL_TEXTURE_CUBE_MAP:
    case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
    case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
    case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB: