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/* $Id: s_trispan.h,v 1.3 2001/09/13 22:12:54 brianp Exp $ */
/*
* Mesa 3-D graphics library
* Version: 3.5
*
* Copyright (C) 1999-2001 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.
*/
#ifndef S_TRISPAN_H
#define S_TRISPAN_H
/*
* The triangle_span structure is used by the triangle template code in
* s_tritemp.h. It describes how colors, Z, texcoords, etc are to be
* interpolated across each scanline of triangle.
* With this structure it's easy to hand-off span rasterization to a
* subroutine instead of doing it all inline like we used to do.
* It also cleans up the local variable namespace a great deal.
*
* It would be interesting to experiment with multiprocessor rasterization
* with this structure. The triangle rasterizer could simply emit a
* stream of these structures which would be consumed by one or more
* span-processing threads which could run in parallel.
*/
/* When the triangle_span struct is initialized, these flags indicates
* which values are needed for rendering the triangle.
*/
#define SPAN_RGBA 0x001
#define SPAN_SPEC 0x002
#define SPAN_INDEX 0x004
#define SPAN_Z 0x008
#define SPAN_FOG 0x010
#define SPAN_TEXTURE 0x020
#define SPAN_INT_TEXTURE 0x040
#define SPAN_LAMBDA 0x080
#define SPAN_FLAT 0x100 /* flat shading? */
struct triangle_span {
GLint x, y;
GLuint count;
GLuint activeMask; /* OR of the SPAN_* flags */
#if CHAN_TYPE == GL_FLOAT
GLfloat red, redStep;
GLfloat green, greenStep;
GLfloat blue, blueStep;
GLfloat alpha, alphaStep;
GLfloat specRed, specRedStep;
GLfloat specGreen, specGreenStep;
GLfloat specBlue, specBlueStep;
#else
GLfixed red, redStep;
GLfixed green, greenStep;
GLfixed blue, blueStep;
GLfixed alpha, alphaStep;
GLfixed specRed, specRedStep;
GLfixed specGreen, specGreenStep;
GLfixed specBlue, specBlueStep;
#endif
GLfixed index, indexStep;
GLfixed z, zStep;
GLfloat fog, fogStep;
GLfloat tex[MAX_TEXTURE_UNITS][4], texStep[MAX_TEXTURE_UNITS][4];
GLfixed intTex[2], intTexStep[2];
/* Needed for texture lambda (LOD) computation */
GLfloat rho[MAX_TEXTURE_UNITS];
GLfloat texWidth[MAX_TEXTURE_UNITS], texHeight[MAX_TEXTURE_UNITS];
};
#endif /* S_TRISPAN_H */
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