diff options
Diffstat (limited to 'src/mesa/main/blend.c')
| -rw-r--r-- | src/mesa/main/blend.c | 53 |
1 files changed, 27 insertions, 26 deletions
diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c index 9600ce81329..0bcefd09748 100644 --- a/src/mesa/main/blend.c +++ b/src/mesa/main/blend.c @@ -1,4 +1,4 @@ -/* $Id: blend.c,v 1.11 2000/02/02 22:08:26 brianp Exp $ */ +/* $Id: blend.c,v 1.12 2000/02/21 14:50:31 brianp Exp $ */ /* * Mesa 3-D graphics library @@ -286,26 +286,27 @@ blend_transparency( GLcontext *ctx, GLuint n, const GLubyte mask[], for (i=0;i<n;i++) { if (mask[i]) { - GLint t = rgba[i][ACOMP]; /* t in [0,255] */ + const GLint t = rgba[i][ACOMP]; /* t in [0,255] */ if (t == 0) { + /* 0% alpha */ rgba[i][RCOMP] = dest[i][RCOMP]; rgba[i][GCOMP] = dest[i][GCOMP]; rgba[i][BCOMP] = dest[i][BCOMP]; rgba[i][ACOMP] = dest[i][ACOMP]; } - else if (t == 255) { - /* no-op */ + else if (t == CHAN_MAX) { + /* 100% alpha, no-op */ } else { - GLint s = 255 - t; - GLint r = (rgba[i][RCOMP] * t + dest[i][RCOMP] * s) >> 8; - GLint g = (rgba[i][GCOMP] * t + dest[i][GCOMP] * s) >> 8; - GLint b = (rgba[i][BCOMP] * t + dest[i][BCOMP] * s) >> 8; - GLint a = (rgba[i][ACOMP] * t + dest[i][ACOMP] * s) >> 8; - ASSERT(r <= 255); - ASSERT(g <= 255); - ASSERT(b <= 255); - ASSERT(a <= 255); + const GLint s = CHAN_MAX - t; + const GLint r = (rgba[i][RCOMP] * t + dest[i][RCOMP] * s) >> 8; + const GLint g = (rgba[i][GCOMP] * t + dest[i][GCOMP] * s) >> 8; + const GLint b = (rgba[i][BCOMP] * t + dest[i][BCOMP] * s) >> 8; + const GLint a = (rgba[i][ACOMP] * t + dest[i][ACOMP] * s) >> 8; + ASSERT(r <= CHAN_MAX); + ASSERT(g <= CHAN_MAX); + ASSERT(b <= CHAN_MAX); + ASSERT(a <= CHAN_MAX); rgba[i][RCOMP] = (GLubyte) r; rgba[i][GCOMP] = (GLubyte) g; rgba[i][BCOMP] = (GLubyte) b; @@ -336,10 +337,10 @@ blend_add( GLcontext *ctx, GLuint n, const GLubyte mask[], GLint g = rgba[i][GCOMP] + dest[i][GCOMP]; GLint b = rgba[i][BCOMP] + dest[i][BCOMP]; GLint a = rgba[i][ACOMP] + dest[i][ACOMP]; - rgba[i][RCOMP] = (GLubyte) MIN2( r, 255 ); - rgba[i][GCOMP] = (GLubyte) MIN2( g, 255 ); - rgba[i][BCOMP] = (GLubyte) MIN2( b, 255 ); - rgba[i][ACOMP] = (GLubyte) MIN2( a, 255 ); + rgba[i][RCOMP] = (GLubyte) MIN2( r, CHAN_MAX ); + rgba[i][GCOMP] = (GLubyte) MIN2( g, CHAN_MAX ); + rgba[i][BCOMP] = (GLubyte) MIN2( b, CHAN_MAX ); + rgba[i][ACOMP] = (GLubyte) MIN2( a, CHAN_MAX ); } } } @@ -429,10 +430,10 @@ static void _BLENDAPI blend_general( GLcontext *ctx, GLuint n, const GLubyte mask[], GLubyte rgba[][4], CONST GLubyte dest[][4] ) { - GLfloat rscale = 1.0F / 255.0F; - GLfloat gscale = 1.0F / 255.0F; - GLfloat bscale = 1.0F / 255.0F; - GLfloat ascale = 1.0F / 255.0F; + GLfloat rscale = 1.0F / CHAN_MAXF; + GLfloat gscale = 1.0F / CHAN_MAXF; + GLfloat bscale = 1.0F / CHAN_MAXF; + GLfloat ascale = 1.0F / CHAN_MAXF; GLuint i; for (i=0;i<n;i++) { @@ -486,7 +487,7 @@ blend_general( GLcontext *ctx, GLuint n, const GLubyte mask[], sR = sG = sB = 1.0F - (GLfloat) Ad * ascale; break; case GL_SRC_ALPHA_SATURATE: - if (As < 1.0F - (GLfloat) Ad * ascale) { + if (As < CHAN_MAX - Ad) { sR = sG = sB = (GLfloat) As * ascale; } else { @@ -705,10 +706,10 @@ blend_general( GLcontext *ctx, GLuint n, const GLubyte mask[], } /* final clamping */ - rgba[i][RCOMP] = (GLubyte) (GLint) CLAMP( r, 0.0F, 255.0F ); - rgba[i][GCOMP] = (GLubyte) (GLint) CLAMP( g, 0.0F, 255.0F ); - rgba[i][BCOMP] = (GLubyte) (GLint) CLAMP( b, 0.0F, 255.0F ); - rgba[i][ACOMP] = (GLubyte) (GLint) CLAMP( a, 0.0F, 255.0F ); + rgba[i][RCOMP] = (GLubyte) (GLint) CLAMP( r, 0.0F, CHAN_MAXF ); + rgba[i][GCOMP] = (GLubyte) (GLint) CLAMP( g, 0.0F, CHAN_MAXF ); + rgba[i][BCOMP] = (GLubyte) (GLint) CLAMP( b, 0.0F, CHAN_MAXF ); + rgba[i][ACOMP] = (GLubyte) (GLint) CLAMP( a, 0.0F, CHAN_MAXF ); } } } |