dri: Add config attributes for color channel shift

The existing mask attributes can only support up to 32 bpp. Introduce
per-channel SHIFT attributes that indicate how many bits, from lsb towards
msb, the bit field is offset. A shift of -1 will indicate that there is no
bit field set for the channel.

As old loaders will still be looking for masks, we set the masks to 0 for
any formats wider than 32 bpp.

Signed-off-by: Kevin Strasser <[email protected]>
Reviewed-by: Adam Jackson <[email protected]>
Reviewed-by: Marek Olšák <[email protected]>
Reviewed-by: Emil Velikov <[email protected]>

2 files changed, 7 insertions, 3 deletions

diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 0128fe12d86..c68be8d01e5 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -1564,9 +1564,12 @@ check_compatible(const struct gl_context *ctx,
        ctxvis->foo != bufvis->foo)     \
       return GL_FALSE
 
-   check_component(redMask);
-   check_component(greenMask);
-   check_component(blueMask);
+   check_component(redShift);
+   check_component(greenShift);
+   check_component(blueShift);
+   check_component(redBits);
+   check_component(greenBits);
+   check_component(blueBits);
    check_component(depthBits);
    check_component(stencilBits);
 
diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
index b38d0a29009..b740671559b 100644
--- a/src/mesa/main/mtypes.h
+++ b/src/mesa/main/mtypes.h
@@ -170,6 +170,7 @@ struct gl_config
 
    GLint redBits, greenBits, blueBits, alphaBits;	/* bits per comp */
    GLuint redMask, greenMask, blueMask, alphaMask;
+   GLint redShift, greenShift, blueShift, alphaShift;
    GLint rgbBits;		/* total bits for rgb */
    GLint indexBits;		/* total bits for colorindex */