#include "glheader.h"
#include "context.h"
#include "colormac.h"
#include "macros.h"
#include "mmath.h"
#include "s_alpha.h"
#include "s_context.h"
GLint
_mesa_alpha_test( const GLcontext *ctx, struct sw_span *span )
{
const GLchan (*rgba)[4] = (const GLchan (*)[4]) span->array->rgba;
GLchan ref;
const GLuint n = span->end;
GLubyte *mask = span->array->mask;
GLuint i;
CLAMPED_FLOAT_TO_CHAN(ref, ctx->Color.AlphaRef);
if (span->arrayMask & SPAN_RGBA) {
switch (ctx->Color.AlphaFunc) {
case GL_LESS:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] < ref);
break;
case GL_LEQUAL:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] <= ref);
break;
case GL_GEQUAL:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] >= ref);
break;
case GL_GREATER:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] > ref);
break;
case GL_NOTEQUAL:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] != ref);
break;
case GL_EQUAL:
for (i = 0; i < n; i++)
mask[i] &= (rgba[i][ACOMP] == ref);
break;
case GL_ALWAYS:
return 1;
case GL_NEVER:
span->writeAll = GL_FALSE;
return 0;
default:
_mesa_problem( ctx, "Invalid alpha test in _mesa_alpha_test" );
return 0;
}
}
else {
#if CHAN_TYPE == GL_FLOAT
const GLfloat alphaStep = span->alphaStep;
GLfloat alpha = span->alpha;
ASSERT(span->interpMask & SPAN_RGBA);
switch (ctx->Color.AlphaFunc) {
case GL_LESS:
for (i = 0; i < n; i++) {
mask[i] &= (alpha < ref);
alpha += alphaStep;
}
break;
case GL_LEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (alpha <= ref);
alpha += alphaStep;
}
break;
case GL_GEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (alpha >= ref);
alpha += alphaStep;
}
break;
case GL_GREATER:
for (i = 0; i < n; i++) {
mask[i] &= (alpha > ref);
alpha += alphaStep;
}
break;
case GL_NOTEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (alpha != ref);
alpha += alphaStep;
}
break;
case GL_EQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (alpha == ref);
alpha += alphaStep;
}
break;
case GL_ALWAYS:
return 1;
case GL_NEVER:
span->writeAll = GL_FALSE;
return 0;
default:
_mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
return 0;
}
#else
const GLfixed alphaStep = span->alphaStep;
GLfixed alpha = span->alpha;
ASSERT(span->interpMask & SPAN_RGBA);
switch (ctx->Color.AlphaFunc) {
case GL_LESS:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) < ref);
alpha += alphaStep;
}
break;
case GL_LEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) <= ref);
alpha += alphaStep;
}
break;
case GL_GEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) >= ref);
alpha += alphaStep;
}
break;
case GL_GREATER:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) > ref);
alpha += alphaStep;
}
break;
case GL_NOTEQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) != ref);
alpha += alphaStep;
}
break;
case GL_EQUAL:
for (i = 0; i < n; i++) {
mask[i] &= (FixedToChan(alpha) == ref);
alpha += alphaStep;
}
break;
case GL_ALWAYS:
return 1;
case GL_NEVER:
span->writeAll = GL_FALSE;
return 0;
default:
_mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
return 0;
}
#endif
}
#if 0
while ((span->start <= span->end) &&
(mask[span->start] == 0))
span->start ++;
while ((span->end >= span->start) &&
(mask[span->end] == 0))
span->end --;
#endif
span->writeAll = GL_FALSE;
if (span->start >= span->end)
return 0;
else
return 1;
}