s_depth.c

mesa-6.5-minigui源码

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2005  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;
	    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_span32");
   }

   return passed;
}



/*
 * Apply depth test to span of fragments.
 */
static GLuint
depth_test_span( GLcontext *ctx, struct sw_span *span)
{
   struct gl_framebuffer *fb = ctx->DrawBuffer;
   struct gl_renderbuffer *rb = fb->_DepthBuffer;
   const GLint x = span->x;
   const GLint y = span->y;
   const GLuint count = span->end;
   const GLuint *zValues = span->array->z;
   GLubyte *mask = span->array->mask;
   GLuint passed;

   ASSERT((span->arrayMask & SPAN_XY) == 0);
   ASSERT(span->arrayMask & SPAN_Z);
   
   if (rb->GetPointer(ctx, rb, 0, 0)) {
      /* Directly access buffer */
      if (rb->DataType == GL_UNSIGNED_SHORT) {
         GLushort *zbuffer = (GLushort *) rb->GetPointer(ctx, rb, x, y);
         passed = depth_test_span16(ctx, count, zbuffer, zValues, mask);
      }
      else {
         GLuint *zbuffer = (GLuint *) rb->GetPointer(ctx, rb, x, y);
         ASSERT(rb->DataType == GL_UNSIGNED_INT);
         passed = depth_test_span32(ctx, count, zbuffer, zValues, mask);
      }
   }
   else {
      /* read depth values from buffer, test, write back */
      if (rb->DataType == GL_UNSIGNED_SHORT) {
         GLushort zbuffer[MAX_WIDTH];
         rb->GetRow(ctx, rb, count, x, y, zbuffer);
         passed = depth_test_span16(ctx, count, zbuffer, zValues, mask );
         rb->PutRow(ctx, rb, count, x, y, zbuffer, NULL);
      }
      else {
         GLuint zbuffer[MAX_WIDTH];
         ASSERT(rb->DataType == GL_UNSIGNED_INT);
         rb->GetRow(ctx, rb, count, x, y, zbuffer);
         passed = depth_test_span32(ctx, count, zbuffer, zValues, mask );
         rb->PutRow(ctx, rb, count, x, y, zbuffer, NULL);
      }
   }

   if (passed < count) {
      span->writeAll = GL_FALSE;
   }
   return passed;
}



#define Z_ADDRESS(X, Y)   (zStart + (Y) * stride + (X))


/*
 * Do depth testing for an array of fragments at assorted locations.
 */
static void
direct_depth_test_pixels16(GLcontext *ctx, GLushort *zStart, GLuint stride,
                           GLuint n, const GLint x[], const GLint y[],
                           const GLuint z[], GLubyte mask[] )
{
   /* 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]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] < *zptr) {
		     /* pass */
		     *zptr = z[i];
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] < *zptr) {
		     /* pass */
		  }
		  else {
		     /* fail */
		     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]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] <= *zptr) {
		     /* pass */
		     *zptr = z[i];
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] <= *zptr) {
		     /* pass */
		  }
		  else {
		     /* fail */
		     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]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] >= *zptr) {
		     /* pass */
		     *zptr = z[i];
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  GLushort *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] >= *zptr) {
		     /* pass */
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }
	 break;
      case GL_GREATER:
         if (ctx->Depth.Mask) {
	    /* Update Z buffer */