diff options
| author | Eric Anholt <eric@anholt.net> | 2010-06-10 00:15:48 -0700 |
|---|---|---|
| committer | Eric Anholt <eric@anholt.net> | 2010-06-10 00:22:00 -0700 |
| commit | ceba688cb54016a9f6ff70761b2c459698bfd7f0 (patch) | |
| tree | 885aaae8993d7198dc6a0e0c09b323ed4e1f6a10 /src/mesa/swrast | |
| parent | 94731797c671d6e46e3e0c94c1a0cec5071c0ac3 (diff) | |
swrast: When reading from a 0-bits r,g,b channel, return 0 not 1.
It looks like we were reading a fractional value, multiplying by an
enormous negative value, then stuffing that value into a bitfield
assuming it was already clamped. This becomes relevant for GL_ALPHA
or R/RG FBOs.
Diffstat (limited to 'src/mesa/swrast')
| -rw-r--r-- | src/mesa/swrast/s_readpix.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/mesa/swrast/s_readpix.c b/src/mesa/swrast/s_readpix.c index 368311e14d..6ad9aceec7 100644 --- a/src/mesa/swrast/s_readpix.c +++ b/src/mesa/swrast/s_readpix.c @@ -265,10 +265,18 @@ adjust_colors(const struct gl_framebuffer *fb, GLuint n, GLfloat rgba[][4]) const GLuint rShift = 8 - fb->Visual.redBits; const GLuint gShift = 8 - fb->Visual.greenBits; const GLuint bShift = 8 - fb->Visual.blueBits; - const GLfloat rScale = 1.0F / (GLfloat) ((1 << fb->Visual.redBits ) - 1); - const GLfloat gScale = 1.0F / (GLfloat) ((1 << fb->Visual.greenBits) - 1); - const GLfloat bScale = 1.0F / (GLfloat) ((1 << fb->Visual.blueBits ) - 1); + GLfloat rScale = 1.0F / (GLfloat) ((1 << fb->Visual.redBits ) - 1); + GLfloat gScale = 1.0F / (GLfloat) ((1 << fb->Visual.greenBits) - 1); + GLfloat bScale = 1.0F / (GLfloat) ((1 << fb->Visual.blueBits ) - 1); GLuint i; + + if (fb->Visual.redBits == 0) + rScale = 0; + if (fb->Visual.greenBits == 0) + gScale = 0; + if (fb->Visual.blueBits == 0) + bScale = 0; + for (i = 0; i < n; i++) { GLint r, g, b; /* convert float back to ubyte */ |