s_depth.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

/*
 * Mesa 3-D graphics library
 * Version:  6.5.1
 *
 * Copyright (C) 1999-2006  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
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


#include "glheader.h"
#include "context.h"
#include "macros.h"
#include "imports.h"
#include "fbobject.h"

#include "s_depth.h"
#include "s_context.h"
#include "s_span.h"


/**
 * Do depth test for a horizontal span of fragments.
 * Input:  zbuffer - array of z values in the zbuffer
 *         z - array of fragment z values
 * Return:  number of fragments which pass the test.
 */
static GLuint
depth_test_span16( GLcontext *ctx, GLuint n,
                   GLushort zbuffer[], const GLuint z[], GLubyte mask[] )
{
   GLuint passed = 0;

   /* switch cases ordered from most frequent to less frequent */
   switch (ctx->Depth.Func) {
      case GL_LESS:
         if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  if (z[i] < zbuffer[i]) {
		     /* pass */
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  if (z[i] < zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_LEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] <= zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] <= zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_GEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] >= zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] >= zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_GREATER:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] > zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] > zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_NOTEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] != zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] != zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_EQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] == zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] == zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_ALWAYS:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  zbuffer[i] = z[i];
		  passed++;
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer or mask */
	    passed = n;
	 }
	 break;
      case GL_NEVER:
         _mesa_bzero(mask, n * sizeof(GLubyte));
	 break;
      default:
         _mesa_problem(ctx, "Bad depth func in depth_test_span16");
   }

   return passed;
}


static GLuint
depth_test_span32( GLcontext *ctx, GLuint n,
                   GLuint zbuffer[], const GLuint z[], GLubyte mask[] )
{
   GLuint passed = 0;

   /* switch cases ordered from most frequent to less frequent */
   switch (ctx->Depth.Func) {
      case GL_LESS:
         if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  if (z[i] < zbuffer[i]) {
		     /* pass */
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  if (z[i] < zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_LEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] <= zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] <= zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_GEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] >= zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] >= zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_GREATER:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] > zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] > zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_NOTEQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] != zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] != zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_EQUAL:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] == zbuffer[i]) {
		     zbuffer[i] = z[i];
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0;i<n;i++) {
	       if (mask[i]) {
		  if (z[i] == zbuffer[i]) {
		     /* pass */
		     passed++;
		  }
		  else {
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_ALWAYS:
	 if (ctx->Depth.Mask) {
	    /* Update Z buffer */
            GLuint i;