[Mesa-dev] [PATCH 7/9] softpipe: don't use 3-component formats

[Brian Paul]

Mesa and gallium don't have a complete set of matching 3-component
texture formats.  For example, 8-bit sRGB unorm.  To fully support
the GL_ARB_copy_image extension we need to have support for all of
these formats: RGB8_UNORM, RGB8_SNORM, RGB8_SRGB, RGB8_UINT, and
RGB8_SINT using the same component order.  Since we don't have that,
disable the 3-component formats for now.
---
 src/gallium/drivers/softpipe/sp_screen.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index aeef8e6..24d79f1 100644
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -360,6 +360,31 @@ softpipe_is_format_supported( struct pipe_screen *screen,
       return FALSE;
    }
 
+   if ((bind & (PIPE_BIND_RENDER_TARGET | PIPE_BIND_SAMPLER_VIEW)) &&
+       ((bind & PIPE_BIND_DISPLAY_TARGET) == 0)) {
+      if (format == PIPE_FORMAT_R8G8B8_UINT ||
+          format == PIPE_FORMAT_R8G8B8_SINT ||
+          format == PIPE_FORMAT_R8G8B8_UNORM ||
+          format == PIPE_FORMAT_R16G16B16_UINT ||
+          format == PIPE_FORMAT_R16G16B16_SINT ||
+          format == PIPE_FORMAT_R16G16B16_UNORM ||
+          format == PIPE_FORMAT_R16G16B16_FLOAT ||
+          format == PIPE_FORMAT_R32G32B32_UINT ||
+          format == PIPE_FORMAT_R32G32B32_SINT ||
+          format == PIPE_FORMAT_R32G32B32_UNORM ||
+          format == PIPE_FORMAT_R32G32B32_FLOAT) {
+         /* Don't support any 3-component formats for rendering/texturing
+          * since we don't support the corresponding 8-bit 3 channel UNORM
+          * formats.  This allows us to support GL_ARB_copy_image between
+          * GL_RGB8 and GL_RGB8UI, for example.  Otherwise, we may be asked to
+          * do a resource copy between PIPE_FORMAT_R8G8B8_UINT and
+          * PIPE_FORMAT_R8G8B8X8_UNORM, for example, which will not work
+          * (different bpp).
+          */
+         return FALSE;
+      }
+   }
+
    if (format_desc->layout == UTIL_FORMAT_LAYOUT_ETC &&
        format != PIPE_FORMAT_ETC1_RGB8)
       return FALSE;
-- 
1.9.1