src/parsec/disk-image/parsec/parsec-benchmark/pkgs/libs/mesa/src/src/mesa/swrast/s_aatriangle.c - public/gem5-resources - Git at Google

 /*
  * Mesa 3-D graphics library
  * Version:  6.5.3
  *
  * Copyright (C) 1999-2007  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.
  */


 /*
  * Antialiased Triangle rasterizers
  */


 #include "glheader.h"
 #include "context.h"
 #include "colormac.h"
 #include "context.h"
 #include "macros.h"
 #include "imports.h"
 #include "s_aatriangle.h"
 #include "s_context.h"
 #include "s_span.h"


 /*
  * Compute coefficients of a plane using the X,Y coords of the v0, v1, v2
  * vertices and the given Z values.
  * A point (x,y,z) lies on plane iff a*x+b*y+c*z+d = 0.
  */
 static INLINE void
 compute_plane(const GLfloat v0[], const GLfloat v1[], const GLfloat v2[],
               GLfloat z0, GLfloat z1, GLfloat z2, GLfloat plane[4])
 {
    const GLfloat px = v1[0] - v0[0];
    const GLfloat py = v1[1] - v0[1];
    const GLfloat pz = z1 - z0;

    const GLfloat qx = v2[0] - v0[0];
    const GLfloat qy = v2[1] - v0[1];
    const GLfloat qz = z2 - z0;

    /* Crossproduct "(a,b,c):= dv1 x dv2" is orthogonal to plane. */
    const GLfloat a = py * qz - pz * qy;
    const GLfloat b = pz * qx - px * qz;
    const GLfloat c = px * qy - py * qx;
    /* Point on the plane = "r*(a,b,c) + w", with fixed "r" depending
       on the distance of plane from origin and arbitrary "w" parallel
       to the plane. */
    /* The scalar product "(r*(a,b,c)+w)*(a,b,c)" is "r*(a^2+b^2+c^2)",
       which is equal to "-d" below. */
    const GLfloat d = -(a * v0[0] + b * v0[1] + c * z0);

    plane[0] = a;
    plane[1] = b;
    plane[2] = c;
    plane[3] = d;
 }


 /*
  * Compute coefficients of a plane with a constant Z value.
  */
 static INLINE void
 constant_plane(GLfloat value, GLfloat plane[4])
 {
    plane[0] = 0.0;
    plane[1] = 0.0;
    plane[2] = -1.0;
    plane[3] = value;
 }

 #define CONSTANT_PLANE(VALUE, PLANE)	\
 do {					\
    PLANE[0] = 0.0F;			\
    PLANE[1] = 0.0F;			\
    PLANE[2] = -1.0F;			\
    PLANE[3] = VALUE;			\
 } while (0)


 /*
  * Solve plane equation for Z at (X,Y).
  */
 static INLINE GLfloat
 solve_plane(GLfloat x, GLfloat y, const GLfloat plane[4])
 {
    ASSERT(plane[2] != 0.0F);
    return (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
 }


 #define SOLVE_PLANE(X, Y, PLANE) \
    ((PLANE[3] + PLANE[0] * (X) + PLANE[1] * (Y)) / -PLANE[2])


 /*
  * Return 1 / solve_plane().
  */
 static INLINE GLfloat
 solve_plane_recip(GLfloat x, GLfloat y, const GLfloat plane[4])
 {
    const GLfloat denom = plane[3] + plane[0] * x + plane[1] * y;
    if (denom == 0.0F)
       return 0.0F;
    else
       return -plane[2] / denom;
 }


 /*
  * Solve plane and return clamped GLchan value.
  */
 static INLINE GLchan
 solve_plane_chan(GLfloat x, GLfloat y, const GLfloat plane[4])
 {
    const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
 #if CHAN_TYPE == GL_FLOAT
    return CLAMP(z, 0.0F, CHAN_MAXF);
 #else
    if (z < 0)
       return 0;
    else if (z > CHAN_MAX)
       return CHAN_MAX;
    return (GLchan) IROUND_POS(z);
 #endif
 }


 static INLINE GLfloat
 plane_dx(const GLfloat plane[4])
 {
    return -plane[0] / plane[2];
 }

 static INLINE GLfloat
 plane_dy(const GLfloat plane[4])
 {
    return -plane[1] / plane[2];
 }


 /*
  * Compute how much (area) of the given pixel is inside the triangle.
  * Vertices MUST be specified in counter-clockwise order.
  * Return:  coverage in [0, 1].
  */
 static GLfloat
 compute_coveragef(const GLfloat v0[3], const GLfloat v1[3],
                   const GLfloat v2[3], GLint winx, GLint winy)
 {
    /* Given a position [0,3]x[0,3] return the sub-pixel sample position.
     * Contributed by Ray Tice.
     *
     * Jitter sample positions -
     * - average should be .5 in x & y for each column
     * - each of the 16 rows and columns should be used once
     * - the rectangle formed by the first four points
     *   should contain the other points
     * - the distrubition should be fairly even in any given direction
     *
     * The pattern drawn below isn't optimal, but it's better than a regular
     * grid.  In the drawing, the center of each subpixel is surrounded by
     * four dots.  The "x" marks the jittered position relative to the
     * subpixel center.
     */
 #define POS(a, b) (0.5+a*4+b)/16
    static const GLfloat samples[16][2] = {
       /* start with the four corners */
       { POS(0, 2), POS(0, 0) },
       { POS(3, 3), POS(0, 2) },
       { POS(0, 0), POS(3, 1) },
       { POS(3, 1), POS(3, 3) },
       /* continue with interior samples */
       { POS(1, 1), POS(0, 1) },
       { POS(2, 0), POS(0, 3) },
       { POS(0, 3), POS(1, 3) },
       { POS(1, 2), POS(1, 0) },
       { POS(2, 3), POS(1, 2) },
       { POS(3, 2), POS(1, 1) },
       { POS(0, 1), POS(2, 2) },
       { POS(1, 0), POS(2, 1) },
       { POS(2, 1), POS(2, 3) },
       { POS(3, 0), POS(2, 0) },
       { POS(1, 3), POS(3, 0) },
       { POS(2, 2), POS(3, 2) }
    };

    const GLfloat x = (GLfloat) winx;
    const GLfloat y = (GLfloat) winy;
    const GLfloat dx0 = v1[0] - v0[0];
    const GLfloat dy0 = v1[1] - v0[1];
    const GLfloat dx1 = v2[0] - v1[0];
    const GLfloat dy1 = v2[1] - v1[1];
    const GLfloat dx2 = v0[0] - v2[0];
    const GLfloat dy2 = v0[1] - v2[1];
    GLint stop = 4, i;
    GLfloat insideCount = 16.0F;

 #ifdef DEBUG
    {
       const GLfloat area = dx0 * dy1 - dx1 * dy0;
       ASSERT(area >= 0.0);
    }
 #endif

    for (i = 0; i < stop; i++) {
       const GLfloat sx = x + samples[i][0];
       const GLfloat sy = y + samples[i][1];
       /* cross product determines if sample is inside or outside each edge */
       GLfloat cross = (dx0 * (sy - v0[1]) - dy0 * (sx - v0[0]));
       /* Check if the sample is exactly on an edge.  If so, let cross be a
        * positive or negative value depending on the direction of the edge.
        */
       if (cross == 0.0F)
          cross = dx0 + dy0;
       if (cross < 0.0F) {
          /* sample point is outside first edge */
          insideCount -= 1.0F;
          stop = 16;
       }
       else {
          /* sample point is inside first edge */
          cross = (dx1 * (sy - v1[1]) - dy1 * (sx - v1[0]));
          if (cross == 0.0F)
             cross = dx1 + dy1;
          if (cross < 0.0F) {
             /* sample point is outside second edge */
             insideCount -= 1.0F;
             stop = 16;
          }
          else {
             /* sample point is inside first and second edges */
             cross = (dx2 * (sy - v2[1]) -  dy2 * (sx - v2[0]));
             if (cross == 0.0F)
                cross = dx2 + dy2;
             if (cross < 0.0F) {
                /* sample point is outside third edge */
                insideCount -= 1.0F;
                stop = 16;
             }
          }
       }
    }
    if (stop == 4)
       return 1.0F;
    else
       return insideCount * (1.0F / 16.0F);
 }


 /*
  * Compute how much (area) of the given pixel is inside the triangle.
  * Vertices MUST be specified in counter-clockwise order.
  * Return:  coverage in [0, 15].
  */
 static GLint
 compute_coveragei(const GLfloat v0[3], const GLfloat v1[3],
                   const GLfloat v2[3], GLint winx, GLint winy)
 {
    /* NOTE: 15 samples instead of 16. */
    static const GLfloat samples[15][2] = {
       /* start with the four corners */
       { POS(0, 2), POS(0, 0) },
       { POS(3, 3), POS(0, 2) },
       { POS(0, 0), POS(3, 1) },
       { POS(3, 1), POS(3, 3) },
       /* continue with interior samples */
       { POS(1, 1), POS(0, 1) },
       { POS(2, 0), POS(0, 3) },
       { POS(0, 3), POS(1, 3) },
       { POS(1, 2), POS(1, 0) },
       { POS(2, 3), POS(1, 2) },
       { POS(3, 2), POS(1, 1) },
       { POS(0, 1), POS(2, 2) },
       { POS(1, 0), POS(2, 1) },
       { POS(2, 1), POS(2, 3) },
       { POS(3, 0), POS(2, 0) },
       { POS(1, 3), POS(3, 0) }
    };
    const GLfloat x = (GLfloat) winx;
    const GLfloat y = (GLfloat) winy;
    const GLfloat dx0 = v1[0] - v0[0];
    const GLfloat dy0 = v1[1] - v0[1];
    const GLfloat dx1 = v2[0] - v1[0];
    const GLfloat dy1 = v2[1] - v1[1];
    const GLfloat dx2 = v0[0] - v2[0];
    const GLfloat dy2 = v0[1] - v2[1];
    GLint stop = 4, i;
    GLint insideCount = 15;

 #ifdef DEBUG
    {
       const GLfloat area = dx0 * dy1 - dx1 * dy0;
       ASSERT(area >= 0.0);
    }
 #endif

    for (i = 0; i < stop; i++) {
       const GLfloat sx = x + samples[i][0];
       const GLfloat sy = y + samples[i][1];
       const GLfloat fx0 = sx - v0[0];
       const GLfloat fy0 = sy - v0[1];
       const GLfloat fx1 = sx - v1[0];
       const GLfloat fy1 = sy - v1[1];
       const GLfloat fx2 = sx - v2[0];
       const GLfloat fy2 = sy - v2[1];
       /* cross product determines if sample is inside or outside each edge */
       GLfloat cross0 = (dx0 * fy0 - dy0 * fx0);
       GLfloat cross1 = (dx1 * fy1 - dy1 * fx1);
       GLfloat cross2 = (dx2 * fy2 - dy2 * fx2);
       /* Check if the sample is exactly on an edge.  If so, let cross be a
        * positive or negative value depending on the direction of the edge.
        */
       if (cross0 == 0.0F)
          cross0 = dx0 + dy0;
       if (cross1 == 0.0F)
          cross1 = dx1 + dy1;
       if (cross2 == 0.0F)
          cross2 = dx2 + dy2;
       if (cross0 < 0.0F || cross1 < 0.0F || cross2 < 0.0F) {
          /* point is outside triangle */
          insideCount--;
          stop = 15;
       }
    }
    if (stop == 4)
       return 15;
    else
       return insideCount;
 }


 static void
 rgba_aa_tri(GLcontext *ctx,
 	    const SWvertex *v0,
 	    const SWvertex *v1,
 	    const SWvertex *v2)
 {
 #define DO_Z
 #define DO_RGBA
 #include "s_aatritemp.h"
 }


 static void
 index_aa_tri(GLcontext *ctx,
 	     const SWvertex *v0,
 	     const SWvertex *v1,
 	     const SWvertex *v2)
 {
 #define DO_Z
 #define DO_ATTRIBS
 #define DO_INDEX
 #include "s_aatritemp.h"
 }


 static void
 general_aa_tri(GLcontext *ctx,
                const SWvertex *v0,
                const SWvertex *v1,
                const SWvertex *v2)
 {
 #define DO_Z
 #define DO_RGBA
 #define DO_ATTRIBS
 #include "s_aatritemp.h"
 }


 /*
  * Examine GL state and set swrast->Triangle to an
  * appropriate antialiased triangle rasterizer function.
  */
 void
 _swrast_set_aa_triangle_function(GLcontext *ctx)
 {
    SWcontext *swrast = SWRAST_CONTEXT(ctx);

    ASSERT(ctx->Polygon.SmoothFlag);

    if (ctx->Texture._EnabledCoordUnits != 0
        || ctx->FragmentProgram._Current
        || swrast->_FogEnabled
        || NEED_SECONDARY_COLOR(ctx)) {
       SWRAST_CONTEXT(ctx)->Triangle = general_aa_tri;
    }
    else if (ctx->Visual.rgbMode) {
       SWRAST_CONTEXT(ctx)->Triangle = rgba_aa_tri;
    }
    else {
       SWRAST_CONTEXT(ctx)->Triangle = index_aa_tri;
    }

    ASSERT(SWRAST_CONTEXT(ctx)->Triangle);
 }
	/*
	* Mesa 3-D graphics library
	* Version: 6.5.3
	*
	* Copyright (C) 1999-2007 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.
	*/


	/*
	* Antialiased Triangle rasterizers
	*/


	#include "glheader.h"
	#include "context.h"
	#include "colormac.h"
	#include "context.h"
	#include "macros.h"
	#include "imports.h"
	#include "s_aatriangle.h"
	#include "s_context.h"
	#include "s_span.h"


	/*
	* Compute coefficients of a plane using the X,Y coords of the v0, v1, v2
	* vertices and the given Z values.
	* A point (x,y,z) lies on plane iff ax+by+c*z+d = 0.
	*/
	static INLINE void
	compute_plane(const GLfloat v0[], const GLfloat v1[], const GLfloat v2[],
	GLfloat z0, GLfloat z1, GLfloat z2, GLfloat plane[4])
	{
	const GLfloat px = v1[0] - v0[0];
	const GLfloat py = v1[1] - v0[1];
	const GLfloat pz = z1 - z0;

	const GLfloat qx = v2[0] - v0[0];
	const GLfloat qy = v2[1] - v0[1];
	const GLfloat qz = z2 - z0;

	/* Crossproduct "(a,b,c):= dv1 x dv2" is orthogonal to plane. */
	const GLfloat a = py * qz - pz * qy;
	const GLfloat b = pz * qx - px * qz;
	const GLfloat c = px * qy - py * qx;
	/* Point on the plane = "r*(a,b,c) + w", with fixed "r" depending
	on the distance of plane from origin and arbitrary "w" parallel
	to the plane. */
	/* The scalar product "(r(a,b,c)+w)(a,b,c)" is "r*(a^2+b^2+c^2)",
	which is equal to "-d" below. */
	const GLfloat d = -(a * v0[0] + b * v0[1] + c * z0);

	plane[0] = a;
	plane[1] = b;
	plane[2] = c;
	plane[3] = d;
	}


	/*
	* Compute coefficients of a plane with a constant Z value.
	*/
	static INLINE void
	constant_plane(GLfloat value, GLfloat plane[4])
	{
	plane[0] = 0.0;
	plane[1] = 0.0;
	plane[2] = -1.0;
	plane[3] = value;
	}

	#define CONSTANT_PLANE(VALUE, PLANE) \
	do { \
	PLANE[0] = 0.0F; \
	PLANE[1] = 0.0F; \
	PLANE[2] = -1.0F; \
	PLANE[3] = VALUE; \
	} while (0)



	/*
	* Solve plane equation for Z at (X,Y).
	*/
	static INLINE GLfloat
	solve_plane(GLfloat x, GLfloat y, const GLfloat plane[4])
	{
	ASSERT(plane[2] != 0.0F);
	return (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
	}


	#define SOLVE_PLANE(X, Y, PLANE) \
	((PLANE[3] + PLANE[0] * (X) + PLANE[1] * (Y)) / -PLANE[2])


	/*
	* Return 1 / solve_plane().
	*/
	static INLINE GLfloat
	solve_plane_recip(GLfloat x, GLfloat y, const GLfloat plane[4])
	{
	const GLfloat denom = plane[3] + plane[0] * x + plane[1] * y;
	if (denom == 0.0F)
	return 0.0F;
	else
	return -plane[2] / denom;
	}


	/*
	* Solve plane and return clamped GLchan value.
	*/
	static INLINE GLchan
	solve_plane_chan(GLfloat x, GLfloat y, const GLfloat plane[4])
	{
	const GLfloat z = (plane[3] + plane[0] * x + plane[1] * y) / -plane[2];
	#if CHAN_TYPE == GL_FLOAT
	return CLAMP(z, 0.0F, CHAN_MAXF);
	#else
	if (z < 0)
	return 0;
	else if (z > CHAN_MAX)
	return CHAN_MAX;
	return (GLchan) IROUND_POS(z);
	#endif
	}


	static INLINE GLfloat
	plane_dx(const GLfloat plane[4])
	{
	return -plane[0] / plane[2];
	}

	static INLINE GLfloat
	plane_dy(const GLfloat plane[4])
	{
	return -plane[1] / plane[2];
	}



	/*
	* Compute how much (area) of the given pixel is inside the triangle.
	* Vertices MUST be specified in counter-clockwise order.
	* Return: coverage in [0, 1].
	*/
	static GLfloat
	compute_coveragef(const GLfloat v0[3], const GLfloat v1[3],
	const GLfloat v2[3], GLint winx, GLint winy)
	{
	/* Given a position [0,3]x[0,3] return the sub-pixel sample position.
	* Contributed by Ray Tice.
	*
	* Jitter sample positions -
	* - average should be .5 in x & y for each column
	* - each of the 16 rows and columns should be used once
	* - the rectangle formed by the first four points
	* should contain the other points
	* - the distrubition should be fairly even in any given direction
	*
	* The pattern drawn below isn't optimal, but it's better than a regular
	* grid. In the drawing, the center of each subpixel is surrounded by
	* four dots. The "x" marks the jittered position relative to the
	* subpixel center.
	*/
	#define POS(a, b) (0.5+a*4+b)/16
	static const GLfloat samples[16][2] = {
	/* start with the four corners */
	{ POS(0, 2), POS(0, 0) },
	{ POS(3, 3), POS(0, 2) },
	{ POS(0, 0), POS(3, 1) },
	{ POS(3, 1), POS(3, 3) },
	/* continue with interior samples */
	{ POS(1, 1), POS(0, 1) },
	{ POS(2, 0), POS(0, 3) },
	{ POS(0, 3), POS(1, 3) },
	{ POS(1, 2), POS(1, 0) },
	{ POS(2, 3), POS(1, 2) },
	{ POS(3, 2), POS(1, 1) },
	{ POS(0, 1), POS(2, 2) },
	{ POS(1, 0), POS(2, 1) },
	{ POS(2, 1), POS(2, 3) },
	{ POS(3, 0), POS(2, 0) },
	{ POS(1, 3), POS(3, 0) },
	{ POS(2, 2), POS(3, 2) }
	};

	const GLfloat x = (GLfloat) winx;
	const GLfloat y = (GLfloat) winy;
	const GLfloat dx0 = v1[0] - v0[0];
	const GLfloat dy0 = v1[1] - v0[1];
	const GLfloat dx1 = v2[0] - v1[0];
	const GLfloat dy1 = v2[1] - v1[1];
	const GLfloat dx2 = v0[0] - v2[0];
	const GLfloat dy2 = v0[1] - v2[1];
	GLint stop = 4, i;
	GLfloat insideCount = 16.0F;

	#ifdef DEBUG
	{
	const GLfloat area = dx0 * dy1 - dx1 * dy0;
	ASSERT(area >= 0.0);
	}
	#endif

	for (i = 0; i < stop; i++) {
	const GLfloat sx = x + samples[i][0];
	const GLfloat sy = y + samples[i][1];
	/* cross product determines if sample is inside or outside each edge */
	GLfloat cross = (dx0 * (sy - v0[1]) - dy0 * (sx - v0[0]));
	/* Check if the sample is exactly on an edge. If so, let cross be a
	* positive or negative value depending on the direction of the edge.
	*/
	if (cross == 0.0F)
	cross = dx0 + dy0;
	if (cross < 0.0F) {
	/* sample point is outside first edge */
	insideCount -= 1.0F;
	stop = 16;
	}
	else {
	/* sample point is inside first edge */
	cross = (dx1 * (sy - v1[1]) - dy1 * (sx - v1[0]));
	if (cross == 0.0F)
	cross = dx1 + dy1;
	if (cross < 0.0F) {
	/* sample point is outside second edge */
	insideCount -= 1.0F;
	stop = 16;
	}
	else {
	/* sample point is inside first and second edges */
	cross = (dx2 * (sy - v2[1]) - dy2 * (sx - v2[0]));
	if (cross == 0.0F)
	cross = dx2 + dy2;
	if (cross < 0.0F) {
	/* sample point is outside third edge */
	insideCount -= 1.0F;
	stop = 16;
	}
	}
	}
	}
	if (stop == 4)
	return 1.0F;
	else
	return insideCount * (1.0F / 16.0F);
	}



	/*
	* Compute how much (area) of the given pixel is inside the triangle.
	* Vertices MUST be specified in counter-clockwise order.
	* Return: coverage in [0, 15].
	*/
	static GLint
	compute_coveragei(const GLfloat v0[3], const GLfloat v1[3],
	const GLfloat v2[3], GLint winx, GLint winy)
	{
	/* NOTE: 15 samples instead of 16. */
	static const GLfloat samples[15][2] = {
	/* start with the four corners */
	{ POS(0, 2), POS(0, 0) },
	{ POS(3, 3), POS(0, 2) },
	{ POS(0, 0), POS(3, 1) },
	{ POS(3, 1), POS(3, 3) },
	/* continue with interior samples */
	{ POS(1, 1), POS(0, 1) },
	{ POS(2, 0), POS(0, 3) },
	{ POS(0, 3), POS(1, 3) },
	{ POS(1, 2), POS(1, 0) },
	{ POS(2, 3), POS(1, 2) },
	{ POS(3, 2), POS(1, 1) },
	{ POS(0, 1), POS(2, 2) },
	{ POS(1, 0), POS(2, 1) },
	{ POS(2, 1), POS(2, 3) },
	{ POS(3, 0), POS(2, 0) },
	{ POS(1, 3), POS(3, 0) }
	};
	const GLfloat x = (GLfloat) winx;
	const GLfloat y = (GLfloat) winy;
	const GLfloat dx0 = v1[0] - v0[0];
	const GLfloat dy0 = v1[1] - v0[1];
	const GLfloat dx1 = v2[0] - v1[0];
	const GLfloat dy1 = v2[1] - v1[1];
	const GLfloat dx2 = v0[0] - v2[0];
	const GLfloat dy2 = v0[1] - v2[1];
	GLint stop = 4, i;
	GLint insideCount = 15;

	#ifdef DEBUG
	{
	const GLfloat area = dx0 * dy1 - dx1 * dy0;
	ASSERT(area >= 0.0);
	}
	#endif

	for (i = 0; i < stop; i++) {
	const GLfloat sx = x + samples[i][0];
	const GLfloat sy = y + samples[i][1];
	const GLfloat fx0 = sx - v0[0];
	const GLfloat fy0 = sy - v0[1];
	const GLfloat fx1 = sx - v1[0];
	const GLfloat fy1 = sy - v1[1];
	const GLfloat fx2 = sx - v2[0];
	const GLfloat fy2 = sy - v2[1];
	/* cross product determines if sample is inside or outside each edge */
	GLfloat cross0 = (dx0 * fy0 - dy0 * fx0);
	GLfloat cross1 = (dx1 * fy1 - dy1 * fx1);
	GLfloat cross2 = (dx2 * fy2 - dy2 * fx2);
	/* Check if the sample is exactly on an edge. If so, let cross be a
	* positive or negative value depending on the direction of the edge.
	*/
	if (cross0 == 0.0F)
	cross0 = dx0 + dy0;
	if (cross1 == 0.0F)
	cross1 = dx1 + dy1;
	if (cross2 == 0.0F)
	cross2 = dx2 + dy2;
	if (cross0 < 0.0F \|\| cross1 < 0.0F \|\| cross2 < 0.0F) {
	/* point is outside triangle */
	insideCount--;
	stop = 15;
	}
	}
	if (stop == 4)
	return 15;
	else
	return insideCount;
	}


	static void
	rgba_aa_tri(GLcontext *ctx,
	const SWvertex *v0,
	const SWvertex *v1,
	const SWvertex *v2)
	{
	#define DO_Z
	#define DO_RGBA
	#include "s_aatritemp.h"
	}


	static void
	index_aa_tri(GLcontext *ctx,
	const SWvertex *v0,
	const SWvertex *v1,
	const SWvertex *v2)
	{
	#define DO_Z
	#define DO_ATTRIBS
	#define DO_INDEX
	#include "s_aatritemp.h"
	}


	static void
	general_aa_tri(GLcontext *ctx,
	const SWvertex *v0,
	const SWvertex *v1,
	const SWvertex *v2)
	{
	#define DO_Z
	#define DO_RGBA
	#define DO_ATTRIBS
	#include "s_aatritemp.h"
	}



	/*
	* Examine GL state and set swrast->Triangle to an
	* appropriate antialiased triangle rasterizer function.
	*/
	void
	_swrast_set_aa_triangle_function(GLcontext *ctx)
	{
	SWcontext *swrast = SWRAST_CONTEXT(ctx);

	ASSERT(ctx->Polygon.SmoothFlag);

	if (ctx->Texture._EnabledCoordUnits != 0
	\|\| ctx->FragmentProgram._Current
	\|\| swrast->_FogEnabled
	\|\| NEED_SECONDARY_COLOR(ctx)) {
	SWRAST_CONTEXT(ctx)->Triangle = general_aa_tri;
	}
	else if (ctx->Visual.rgbMode) {
	SWRAST_CONTEXT(ctx)->Triangle = rgba_aa_tri;
	}
	else {
	SWRAST_CONTEXT(ctx)->Triangle = index_aa_tri;
	}

	ASSERT(SWRAST_CONTEXT(ctx)->Triangle);
	}