i965: asst. fixes, work-arounds for FBOs and render to texture

OpenGL allows mixing and matching depth and stencil renderbuffers in
framebuffer objects while the hardware really only supports interleaved
depth/stencil buffers.  This makes for some tricky buffer management.

An extra wrinkle is the situation where the user allocates a 16bpp depth
texture or renderbuffer then tries to render to it along with a stencil
buffer.  We'd have to promote the 16bpp Z values to 24-bit Z values and
mix in the stencil values to setup the depth/stencil renderbuffer.

There's no support for that now, so always allocate 32bpp depth textures/
renderbuffers for now.

1 files changed, 8 insertions, 2 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_tex_format.c b/src/mesa/drivers/dri/intel/intel_tex_format.c
index 2be060dd3e..5e418ac446 100644
--- a/src/mesa/drivers/dri/intel/intel_tex_format.c
+++ b/src/mesa/drivers/dri/intel/intel_tex_format.c
@@ -134,8 +134,14 @@ intelChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
    case GL_DEPTH_COMPONENT16:
    case GL_DEPTH_COMPONENT24:
    case GL_DEPTH_COMPONENT32:
+#if 0
       return &_mesa_texformat_z16;
-
+#else
+      /* fall-through.
+       * 16bpp depth texture can't be paired with a stencil buffer so
+       * always used combined depth/stencil format.
+       */
+#endif
    case GL_DEPTH_STENCIL_EXT:
    case GL_DEPTH24_STENCIL8_EXT:
       return &_mesa_texformat_s8_z24;
@@ -158,7 +164,7 @@ intelChooseTextureFormat(GLcontext * ctx, GLint internalFormat,
    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT:
    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT:
    case GL_COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT:
-     return &_mesa_texformat_srgb_dxt1;
+      return &_mesa_texformat_srgb_dxt1;
 #endif
 
    default: