s_depth.c

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

	    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, SWspan *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 */
            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_NOTEQUAL:
         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_EQUAL:
         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_ALWAYS:
	 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]);
		  *zptr = z[i];
	       }
	    }
	 }
	 else {
	    /* Don't update Z buffer or mask */
	 }
	 break;
      case GL_NEVER:
	 /* depth test never passes */
         _mesa_bzero(mask, n * sizeof(GLubyte));
	 break;
      default:
         _mesa_problem(ctx, "Bad depth func in direct_depth_test_pixels");
   }
}



/*
 * Do depth testing for an array of fragments with direct access to zbuffer.
 */
static void
direct_depth_test_pixels32(GLcontext *ctx, GLuint *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]) {
		  GLuint *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]) {
		  GLuint *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]) {
		  GLuint *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]) {
		  GLuint *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]) {
		  GLuint *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]) {
		  GLuint *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 */
            GLuint i;
	    for (i=0; i<n; i++) {
	       if (mask[i]) {
		  GLuint *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]) {
		  GLuint *zptr = Z_ADDRESS(x[i], y[i]);
		  if (z[i] > *zptr) {
		     /* pass */
		  }
		  else {
		     /* fail */
		     mask[i] = 0;
		  }
	       }
	    }
	 }