-/* $Id: s_alpha.c,v 1.3 2001/03/03 20:33:30 brianp Exp $ */
+/* $Id: s_alpha.c,v 1.12 2002/10/04 19:10:12 brianp Exp $ */
/*
* Mesa 3-D graphics library
- * Version: 3.3
- *
- * Copyright (C) 1999-2000 Brian Paul All Rights Reserved.
- *
+ * Version: 4.1
+ *
+ * Copyright (C) 1999-2002 Brian Paul All Rights Reserved.
+ *
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
- *
+ *
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
- *
+ *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
+/**
+ * \file swrast/s_alpha.c
+ * \brief Functions to apply alpha test.
+ */
#include "glheader.h"
#include "context.h"
#include "mmath.h"
#include "s_alpha.h"
+#include "s_context.h"
-
-
-
-/*
- * Apply the alpha test to a span of pixels.
- * In: rgba - array of pixels
- * In/Out: mask - current pixel mask. Pixels which fail the alpha test
- * will set the corresponding mask flag to 0.
- * Return: 0 = all pixels in the span failed the alpha test.
- * 1 = one or more pixels passed the alpha test.
+/**
+ * \fn GLint _mesa_alpha_test( const GLcontext *ctx, struct sw_span *span )
+ * \brief Apply the alpha test to a span of pixels.
+ * \return
+ * - "0" = all pixels in the span failed the alpha test.
+ * - "1" = one or more pixels passed the alpha test.
*/
GLint
-_mesa_alpha_test( const GLcontext *ctx,
- GLuint n, CONST GLchan rgba[][4], GLubyte mask[] )
+_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;
- GLchan ref = ctx->Color.AlphaRef;
- /* switch cases ordered from most frequent to less frequent */
- switch (ctx->Color.AlphaFunc) {
- case GL_LESS:
- for (i=0;i<n;i++) {
- mask[i] &= (rgba[i][ACOMP] < ref);
- }
- return 1;
- case GL_LEQUAL:
- for (i=0;i<n;i++)
- mask[i] &= (rgba[i][ACOMP] <= ref);
- return 1;
- case GL_GEQUAL:
- for (i=0;i<n;i++) {
- mask[i] &= (rgba[i][ACOMP] >= ref);
- }
- return 1;
- case GL_GREATER:
- for (i=0;i<n;i++) {
- mask[i] &= (rgba[i][ACOMP] > ref);
- }
- return 1;
- case GL_NOTEQUAL:
- for (i=0;i<n;i++) {
- mask[i] &= (rgba[i][ACOMP] != ref);
- }
- return 1;
- case GL_EQUAL:
- for (i=0;i<n;i++) {
- mask[i] &= (rgba[i][ACOMP] == ref);
- }
- return 1;
- case GL_ALWAYS:
- /* do nothing */
- return 1;
- case GL_NEVER:
- /* caller should check for zero! */
- return 0;
- default:
- _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
- return 0;
+ CLAMPED_FLOAT_TO_CHAN(ref, ctx->Color.AlphaRef);
+
+ if (span->arrayMask & SPAN_RGBA) {
+ /* Use the array values */
+ 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:
+ /* do nothing */
+ return 1;
+ case GL_NEVER:
+ /* caller should check for zero! */
+ span->writeAll = GL_FALSE;
+ return 0;
+ default:
+ _mesa_problem( ctx, "Invalid alpha test in _mesa_alpha_test" );
+ return 0;
+ }
}
- /* Never get here */
- /*return 1;*/
+ else {
+ /* Use the interpolation values */
+#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:
+ /* do nothing */
+ return 1;
+ case GL_NEVER:
+ /* caller should check for zero! */
+ span->writeAll = GL_FALSE;
+ return 0;
+ default:
+ _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+ return 0;
+ }
+#else
+ /* 8 or 16-bit channel interpolation */
+ 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:
+ /* do nothing */
+ return 1;
+ case GL_NEVER:
+ /* caller should check for zero! */
+ span->writeAll = GL_FALSE;
+ return 0;
+ default:
+ _mesa_problem( ctx, "Invalid alpha test in gl_alpha_test" );
+ return 0;
+ }
+#endif /* CHAN_TYPE */
+ }
+
+#if 0
+ /* XXXX This causes conformance failures!!!! */
+ 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;
}
projects / mesa.git / blobdiff