mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
873 lines
29 KiB
873 lines
29 KiB
/*
|
|
** Copyright 1991, 1992, 1993, Silicon Graphics, Inc.
|
|
** All Rights Reserved.
|
|
**
|
|
** This is UNPUBLISHED PROPRIETARY SOURCE CODE of Silicon Graphics, Inc.;
|
|
** the contents of this file may not be disclosed to third parties, copied or
|
|
** duplicated in any form, in whole or in part, without the prior written
|
|
** permission of Silicon Graphics, Inc.
|
|
**
|
|
** RESTRICTED RIGHTS LEGEND:
|
|
** Use, duplication or disclosure by the Government is subject to restrictions
|
|
** as set forth in subdivision (c)(1)(ii) of the Rights in Technical Data
|
|
** and Computer Software clause at DFARS 252.227-7013, and/or in similar or
|
|
** successor clauses in the FAR, DOD or NASA FAR Supplement. Unpublished -
|
|
** rights reserved under the Copyright Laws of the United States.
|
|
*/
|
|
#include "precomp.h"
|
|
#pragma hdrstop
|
|
|
|
#ifdef GL_WIN_phong_shading
|
|
#include "phong.h"
|
|
#endif //GL_WIN_phong_shading
|
|
|
|
|
|
/*
|
|
** Normal form of a line: Ax + By + C = 0. When evaluated at a point P,
|
|
** the value is zero when P is on the line. For points off the line,
|
|
** the sign of the value determines which side of the line P is on.
|
|
*/
|
|
typedef struct {
|
|
__GLfloat a, b, c;
|
|
|
|
/*
|
|
** The sign of an edge is determined by plugging the third vertex
|
|
** of the triangle into the line equation. This flag is GL_TRUE when
|
|
** the sign is positive.
|
|
*/
|
|
GLboolean edgeSign;
|
|
} __glLineEquation;
|
|
|
|
/*
|
|
** Machine state for rendering triangles.
|
|
*/
|
|
typedef struct {
|
|
__GLfloat dyAB;
|
|
__GLfloat dyBC;
|
|
__glLineEquation ab;
|
|
__glLineEquation bc;
|
|
__glLineEquation ca;
|
|
__GLfloat area;
|
|
GLint areaSign;
|
|
} __glTriangleMachine;
|
|
|
|
/*
|
|
** Plane equation coefficients. One plane equation exists for each of
|
|
** the parameters being computed across the surface of the triangle.
|
|
*/
|
|
typedef struct {
|
|
__GLfloat a, b, c, d;
|
|
} __glPlaneEquation;
|
|
|
|
/*
|
|
** Cache for some of the coverage computation constants.
|
|
*/
|
|
typedef struct {
|
|
__GLfloat dx, dy;
|
|
GLint samples;
|
|
GLint samplesSquared;
|
|
__GLfloat samplesSquaredInv;
|
|
GLboolean lastCoverageWasOne;
|
|
__GLfloat leftDelta, rightDelta;
|
|
__GLfloat bottomDelta, topDelta;
|
|
} __glCoverageStuff;
|
|
|
|
/*
|
|
** Compute the constants A, B and C for a line equation in the general
|
|
** form: Ax + By + C = 0. A given point at (x,y) can be plugged into
|
|
** the left side of the equation and yield a number which indiates whether
|
|
** or not the point is on the line. If the result is zero, then the point
|
|
** is on the line. The sign of the result determines which side of
|
|
** the line the point is on. To handle tie cases properly we need a way
|
|
** to assign a point on the edge to only one triangle. To do this, we
|
|
** look at the sign of the equation evaluated at "c". For edges whose
|
|
** sign at "c" is positive, we allow points on the edge to be in the
|
|
** triangle.
|
|
*/
|
|
static void FindLineEqation(__glLineEquation *eq, const __GLvertex *a,
|
|
const __GLvertex *b, const __GLvertex *c)
|
|
{
|
|
__GLfloat dy, dx, valueAtC;
|
|
|
|
/*
|
|
** Sort a,b so that the ordering of the verticies is consistent,
|
|
** regardless of the order given to this procedure.
|
|
*/
|
|
if (b->window.y < a->window.y) {
|
|
const __GLvertex *temp = b;
|
|
b = a;
|
|
a = temp;
|
|
} else
|
|
if ((b->window.y == a->window.y) && (b->window.x < a->window.x)) {
|
|
const __GLvertex *temp = b;
|
|
b = a;
|
|
a = temp;
|
|
}
|
|
|
|
dy = b->window.y - a->window.y;
|
|
dx = b->window.x - a->window.x;
|
|
eq->a = -dy;
|
|
eq->b = dx;
|
|
eq->c = dy * a->window.x - dx * a->window.y;
|
|
|
|
valueAtC = eq->a * c->window.x + eq->b * c->window.y + eq->c;
|
|
if (valueAtC > 0) {
|
|
eq->edgeSign = GL_TRUE;
|
|
} else {
|
|
eq->edgeSign = GL_FALSE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Given three points in (x,y,p) find the plane equation coeffecients
|
|
** for the plane that contains the three points. First find the cross
|
|
** product of two of the vectors defined by the three points, then
|
|
** use one of the points to find "d".
|
|
*/
|
|
static void FindPlaneEquation(__glPlaneEquation *eq,
|
|
const __GLvertex *a, const __GLvertex *b,
|
|
const __GLvertex *c, __GLfloat p1,
|
|
__GLfloat p2, __GLfloat p3)
|
|
{
|
|
__GLfloat v1x, v1y, v1p;
|
|
__GLfloat v2x, v2y, v2p;
|
|
__GLfloat nx, ny, np, k;
|
|
|
|
/* find vector v1 */
|
|
v1x = b->window.x - a->window.x;
|
|
v1y = b->window.y - a->window.y;
|
|
v1p = p2 - p1;
|
|
|
|
/* find vector v2 */
|
|
v2x = c->window.x - a->window.x;
|
|
v2y = c->window.y - a->window.y;
|
|
v2p = p3 - p1;
|
|
|
|
/* find the cross product (== normal) for the plane */
|
|
nx = v1y*v2p - v1p*v2y;
|
|
ny = v1p*v2x - v1x*v2p;
|
|
np = v1x*v2y - v1y*v2x;
|
|
|
|
/*
|
|
** V dot N = k. Find k. We can use any of the three points on
|
|
** the plane, so we use a.
|
|
*/
|
|
k = a->window.x*nx + a->window.y*ny + p1*np;
|
|
|
|
/*
|
|
** Finally, setup the plane equation coeffecients. Force c to be one
|
|
** by dividing everything through by c.
|
|
*/
|
|
eq->a = nx / np;
|
|
eq->b = ny / np;
|
|
eq->c = ((__GLfloat) 1.0);
|
|
eq->d = -k / np;
|
|
}
|
|
|
|
/*
|
|
** Solve for p in the plane equation.
|
|
*/
|
|
static __GLfloat FindP(__glPlaneEquation *eq, __GLfloat x, __GLfloat y)
|
|
{
|
|
return -(eq->a * x + eq->b * y + eq->d);
|
|
}
|
|
|
|
/*
|
|
** See if a given point is on the same side of the edge as the other
|
|
** vertex in the triangle not part of this edge. When the line
|
|
** equation evaluates to zero, make points which are on lines with
|
|
** a negative edge sign (edgeSign GL_FALSE) part of the triangle.
|
|
*/
|
|
#define In(eq,x,y) \
|
|
(((eq)->a * (x) + (eq)->b * (y) + (eq)->c > 0) == (eq)->edgeSign)
|
|
|
|
/*
|
|
** Determine if the point x,y is in or out of the triangle. Evaluate
|
|
** each line equation for the point and compare the sign of the result
|
|
** with the edgeSign flag.
|
|
*/
|
|
#define Inside(tm,x,y) \
|
|
(In(&(tm)->ab, x, y) && In(&(tm)->bc, x, y) && In(&(tm)->ca, x, y))
|
|
|
|
#define FILTER_WIDTH ((__GLfloat) 1.0)
|
|
#define FILTER_HEIGHT ((__GLfloat) 1.0)
|
|
|
|
/*
|
|
** Precompute stuff that is constant for all coverage tests.
|
|
*/
|
|
static void FASTCALL ComputeCoverageStuff(__glCoverageStuff *cs, GLint samples)
|
|
{
|
|
__GLfloat dx, dy, fs = samples;
|
|
__GLfloat half = ((__GLfloat) 0.5);
|
|
|
|
cs->dx = dx = FILTER_WIDTH / fs;
|
|
cs->dy = dy = FILTER_HEIGHT / fs;
|
|
cs->leftDelta = -(FILTER_WIDTH / 2) + dx * half;
|
|
cs->rightDelta = (FILTER_WIDTH / 2) - dx * half;
|
|
cs->bottomDelta = -(FILTER_HEIGHT / 2) + dy * half;
|
|
cs->topDelta = (FILTER_HEIGHT / 2) - dy * half;
|
|
cs->samplesSquared = samples * samples;
|
|
cs->samplesSquaredInv = ((__GLfloat) 1.0) / cs->samplesSquared;
|
|
cs->samples = samples;
|
|
}
|
|
|
|
/*
|
|
** Return an estimate of the pixel coverage using sub-sampling.
|
|
*/
|
|
static __GLfloat Coverage(__glTriangleMachine *tm, __GLfloat *xs,
|
|
__GLfloat *ys, __glCoverageStuff *cs)
|
|
{
|
|
GLint xx, yy, hits, samples;
|
|
__GLfloat dx, dy, yBottom, px, py;
|
|
__GLfloat minX, minY, maxX, maxY;
|
|
|
|
hits = 0;
|
|
samples = cs->samples;
|
|
dx = cs->dx;
|
|
dy = cs->dy;
|
|
px = *xs + cs->leftDelta;
|
|
yBottom = *ys + cs->bottomDelta;
|
|
|
|
/*
|
|
** If the last coverage was one (the pixel to the left in x from us),
|
|
** then if the upper right and lower right sample positions are
|
|
** also in then this entire pixel must be in.
|
|
*/
|
|
if (cs->lastCoverageWasOne) {
|
|
__GLfloat urx, ury;
|
|
urx = *xs + cs->rightDelta;
|
|
ury = *ys + cs->topDelta;
|
|
if (Inside(tm, urx, ury) && Inside(tm, urx, yBottom)) {
|
|
return ((__GLfloat) 1.0);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Setup minimum and maximum x,y coordinates. The min and max values
|
|
** are used to find a "good" point that is actually within the
|
|
** triangle so that parameter values can be computed correctly.
|
|
*/
|
|
minX = 999999;
|
|
maxX = __glMinusOne;
|
|
minY = 999999;
|
|
maxY = __glMinusOne;
|
|
for (xx = 0; xx < samples; xx++) {
|
|
py = yBottom;
|
|
for (yy = 0; yy < samples; yy++) {
|
|
if (Inside(tm, px, py)) {
|
|
if (px < minX) minX = px;
|
|
if (px > maxX) maxX = px;
|
|
if (py < minY) minY = py;
|
|
if (py > maxY) maxY = py;
|
|
hits++;
|
|
}
|
|
py += dy;
|
|
}
|
|
px += dx;
|
|
}
|
|
if (hits) {
|
|
/*
|
|
** Return the average of the two coordinates which is guaranteed
|
|
** to be in the triangle.
|
|
*/
|
|
*xs = (minX + maxX) * ((__GLfloat) 0.5);
|
|
*ys = (minY + maxY) * ((__GLfloat) 0.5);
|
|
if (hits == cs->samplesSquared) {
|
|
/* Keep track when the last coverage was one */
|
|
cs->lastCoverageWasOne = GL_TRUE;
|
|
return ((__GLfloat) 1.0);
|
|
}
|
|
}
|
|
cs->lastCoverageWasOne = GL_FALSE;
|
|
return hits * cs->samplesSquaredInv;
|
|
}
|
|
|
|
/*
|
|
** Force f to have no more precision than the subpixel precision allows.
|
|
** Even though "f" is biased this still works and does not generate an
|
|
** overflow.
|
|
*/
|
|
#define __GL_FIX_PRECISION(f) \
|
|
((__GLfloat) ((GLint) (f * (1 << gc->constants.subpixelBits))) \
|
|
/ (1 << gc->constants.subpixelBits))
|
|
|
|
void FASTCALL __glFillAntiAliasedTriangle(__GLcontext *gc, __GLvertex *a,
|
|
__GLvertex *b, __GLvertex *c,
|
|
GLboolean ccw)
|
|
{
|
|
__glTriangleMachine tm;
|
|
__glCoverageStuff cs;
|
|
__GLcolor *ca, *cb, *cc, *flatColor;
|
|
GLint x, y, left, right, bottom, top, samples;
|
|
__glPlaneEquation qwp, zp, rp, gp, bp, ap, ezp, sp, tp;
|
|
__glPlaneEquation fp;
|
|
GLboolean rgbMode;
|
|
__GLcolorBuffer *cfb = gc->drawBuffer;
|
|
__GLfloat zero = __glZero;
|
|
__GLfloat area, ax, bx, cx, ay, by, cy;
|
|
__GLshade *sh = &gc->polygon.shader;
|
|
GLuint modeFlags = gc->polygon.shader.modeFlags;
|
|
|
|
#ifdef __GL_LINT
|
|
ccw = ccw;
|
|
#endif
|
|
/*
|
|
** Recompute the area of the triangle after constraining the incoming
|
|
** coordinates to the subpixel precision. The viewport bias gives
|
|
** more precision (typically) than the subpixel precision. Because of
|
|
** this the algorithim below can fail to reject an essentially empty
|
|
** triangle and instead fill a large area. The scan converter fill
|
|
** routines (eg polydraw.c) don't have this trouble because of the
|
|
** very nature of edge walking.
|
|
**
|
|
** NOTE: Notice that here as in other places, when the area calculation
|
|
** is done we are careful to do it as a series of subtractions followed by
|
|
** multiplications. This is done to guarantee that no overflow will
|
|
** occur (remember that the coordinates are biased by a potentially large
|
|
** number, and that multiplying two biased numbers will square the bias).
|
|
*/
|
|
ax = __GL_FIX_PRECISION(a->window.x);
|
|
bx = __GL_FIX_PRECISION(b->window.x);
|
|
cx = __GL_FIX_PRECISION(c->window.x);
|
|
ay = __GL_FIX_PRECISION(a->window.y);
|
|
by = __GL_FIX_PRECISION(b->window.y);
|
|
cy = __GL_FIX_PRECISION(c->window.y);
|
|
area = (ax - cx) * (by - cy) - (bx - cx) * (ay - cy);
|
|
if (area == zero) {
|
|
return;
|
|
}
|
|
|
|
ca = a->color;
|
|
cb = b->color;
|
|
cc = c->color;
|
|
flatColor = gc->vertex.provoking->color;
|
|
|
|
/*
|
|
** Construct plane equations for all of the parameters that are
|
|
** computed for the triangle: z, r, g, b, a, s, t, f
|
|
*/
|
|
if (modeFlags & __GL_SHADE_DEPTH_ITER) {
|
|
FindPlaneEquation(&zp, a, b, c, a->window.z, b->window.z, c->window.z);
|
|
}
|
|
|
|
if (modeFlags & __GL_SHADE_COMPUTE_FOG)
|
|
{
|
|
FindPlaneEquation(&ezp, a, b, c, a->eyeZ, b->eyeZ, c->eyeZ);
|
|
}
|
|
else if (modeFlags & __GL_SHADE_INTERP_FOG)
|
|
{
|
|
FindPlaneEquation(&fp, a, b, c, a->fog, b->fog, c->fog);
|
|
}
|
|
|
|
if (modeFlags & __GL_SHADE_TEXTURE) {
|
|
__GLfloat one = __glOne;
|
|
__GLfloat aWInv = a->window.w;
|
|
__GLfloat bWInv = b->window.w;
|
|
__GLfloat cWInv = c->window.w;
|
|
FindPlaneEquation(&qwp, a, b, c, a->texture.w * aWInv,
|
|
b->texture.w * bWInv, c->texture.w * cWInv);
|
|
FindPlaneEquation(&sp, a, b, c, a->texture.x * aWInv,
|
|
b->texture.x * bWInv, c->texture.x * cWInv);
|
|
FindPlaneEquation(&tp, a, b, c, a->texture.y * aWInv,
|
|
b->texture.y * bWInv, c->texture.y * cWInv);
|
|
}
|
|
rgbMode = gc->modes.rgbMode;
|
|
if (modeFlags & __GL_SHADE_SMOOTH) {
|
|
FindPlaneEquation(&rp, a, b, c, ca->r, cb->r, cc->r);
|
|
if (rgbMode) {
|
|
FindPlaneEquation(&gp, a, b, c, ca->g, cb->g, cc->g);
|
|
FindPlaneEquation(&bp, a, b, c, ca->b, cb->b, cc->b);
|
|
FindPlaneEquation(&ap, a, b, c, ca->a, cb->a, cc->a);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Compute general form of the line equations for each of the
|
|
** edges of the triangle.
|
|
*/
|
|
FindLineEqation(&tm.ab, a, b, c);
|
|
FindLineEqation(&tm.bc, b, c, a);
|
|
FindLineEqation(&tm.ca, c, a, b);
|
|
|
|
/* Compute bounding box of the triangle */
|
|
left = (GLint)a->window.x;
|
|
if (b->window.x < left) left = (GLint)b->window.x;
|
|
if (c->window.x < left) left = (GLint)c->window.x;
|
|
right = (GLint)a->window.x;
|
|
if (b->window.x > right) right = (GLint)b->window.x;
|
|
if (c->window.x > right) right = (GLint)c->window.x;
|
|
bottom = (GLint)a->window.y;
|
|
if (b->window.y < bottom) bottom = (GLint)b->window.y;
|
|
if (c->window.y < bottom) bottom = (GLint)c->window.y;
|
|
top = (GLint)a->window.y;
|
|
if (b->window.y > top) top = (GLint)b->window.y;
|
|
if (c->window.y > top) top = (GLint)c->window.y;
|
|
|
|
/* Bloat the bounding box when anti aliasing */
|
|
left -= (GLint)FILTER_WIDTH;
|
|
right += (GLint)FILTER_WIDTH;
|
|
bottom -= (GLint)FILTER_HEIGHT;
|
|
top += (GLint)FILTER_HEIGHT;
|
|
|
|
/* Init coverage computations */
|
|
samples = (gc->state.hints.polygonSmooth == GL_NICEST) ? 8 : 4;
|
|
ComputeCoverageStuff(&cs, samples);
|
|
|
|
/* Scan over the bounding box of the triangle */
|
|
for (y = bottom; y <= top; y++) {
|
|
cs.lastCoverageWasOne = GL_FALSE;
|
|
for (x = left; x <= right; x++) {
|
|
__GLfloat coverage;
|
|
__GLfloat xs, ys;
|
|
|
|
if (modeFlags & __GL_SHADE_STIPPLE) {
|
|
/*
|
|
** Check the window coordinate against the stipple and
|
|
** and see if the pixel can be written
|
|
*/
|
|
GLint row = y & 31;
|
|
GLint col = x & 31;
|
|
if ((gc->polygon.stipple[row] & (1<<col)) == 0) {
|
|
/*
|
|
** Stipple bit is clear. Do not render this pixel
|
|
** of the triangle.
|
|
*/
|
|
continue;
|
|
}
|
|
}
|
|
|
|
xs = x + __glHalf; /* sample point is at pixel center */
|
|
ys = y + __glHalf;
|
|
coverage = Coverage(&tm, &xs, &ys, &cs);
|
|
if (coverage != zero) {
|
|
__GLfragment frag;
|
|
|
|
/*
|
|
** Fill in fragment for rendering. First compute the color
|
|
** of the fragment.
|
|
*/
|
|
if (modeFlags & __GL_SHADE_SMOOTH) {
|
|
frag.color.r = FindP(&rp, xs, ys);
|
|
if (rgbMode) {
|
|
frag.color.g = FindP(&gp, xs, ys);
|
|
frag.color.b = FindP(&bp, xs, ys);
|
|
frag.color.a = FindP(&ap, xs, ys);
|
|
}
|
|
} else {
|
|
frag.color.r = flatColor->r;
|
|
if (rgbMode) {
|
|
frag.color.g = flatColor->g;
|
|
frag.color.b = flatColor->b;
|
|
frag.color.a = flatColor->a;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Texture the fragment.
|
|
*/
|
|
if (modeFlags & __GL_SHADE_TEXTURE) {
|
|
__GLfloat qw, s, t, rho;
|
|
|
|
qw = FindP(&qwp, xs, ys);
|
|
s = FindP(&sp, xs, ys);
|
|
t = FindP(&tp, xs, ys);
|
|
rho = (*gc->procs.calcPolygonRho)(gc, sh, s, t, qw);
|
|
#ifdef NT
|
|
if( qw == (__GLfloat) 0.0 )
|
|
s = t = (__GLfloat) 0;
|
|
else {
|
|
s /= qw;
|
|
t /= qw;
|
|
}
|
|
#else
|
|
s /= qw;
|
|
t /= qw;
|
|
#endif
|
|
(*gc->procs.texture)(gc, &frag.color, s, t, rho);
|
|
}
|
|
|
|
/*
|
|
** Fog the resulting color.
|
|
*/
|
|
if (modeFlags & __GL_SHADE_COMPUTE_FOG)
|
|
{
|
|
__GLfloat eyeZ = FindP(&ezp, xs, ys);
|
|
__glFogFragmentSlow(gc, &frag, eyeZ);
|
|
}
|
|
else if (modeFlags & __GL_SHADE_INTERP_FOG)
|
|
{
|
|
__GLfloat fog = FindP(&fp, xs, ys);
|
|
__glFogColorSlow(gc, &(frag.color), &(frag.color), fog);
|
|
}
|
|
|
|
/*
|
|
** Apply anti-aliasing effect
|
|
*/
|
|
if (rgbMode) {
|
|
frag.color.a *= coverage;
|
|
} else {
|
|
frag.color.r =
|
|
__glBuildAntiAliasIndex(frag.color.r,
|
|
coverage);
|
|
}
|
|
|
|
/*
|
|
** Finally, render the fragment.
|
|
*/
|
|
frag.x = (GLint)xs;
|
|
frag.y = (GLint)ys;
|
|
if (modeFlags & __GL_SHADE_DEPTH_ITER) {
|
|
frag.z = (__GLzValue)FindP(&zp, xs, ys);
|
|
}
|
|
(*gc->procs.store)(cfb, &frag);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef GL_WIN_phong_shading
|
|
|
|
void FASTCALL __glFillAntiAliasedPhongTriangle(__GLcontext *gc, __GLvertex *a,
|
|
__GLvertex *b, __GLvertex *c,
|
|
GLboolean ccw)
|
|
{
|
|
#if 1
|
|
__glTriangleMachine tm;
|
|
__glCoverageStuff cs;
|
|
__GLcolor *ca, *cb, *cc, *flatColor;
|
|
GLint x, y, left, right, bottom, top, samples;
|
|
__glPlaneEquation qwp, zp, rp, gp, bp, ap, ezp, sp, tp;
|
|
__glPlaneEquation exp, eyp, ewp, nxp, nyp, nzp;
|
|
__glPlaneEquation fp;
|
|
GLboolean rgbMode;
|
|
__GLcolorBuffer *cfb = gc->drawBuffer;
|
|
__GLfloat zero = __glZero;
|
|
__GLfloat area, ax, bx, cx, ay, by, cy;
|
|
__GLshade *sh = &gc->polygon.shader;
|
|
GLuint modeFlags = gc->polygon.shader.modeFlags;
|
|
__GLcoord *na, *nb, *nc, ea, eb, ec;
|
|
GLuint msm_colorMaterialChange, flags=0;
|
|
GLboolean needColor, needEye;
|
|
__GLphongShader *phong = &gc->polygon.shader.phong;
|
|
|
|
if (gc->polygon.shader.phong.face == __GL_FRONTFACE)
|
|
msm_colorMaterialChange = gc->light.back.colorMaterialChange;
|
|
else
|
|
msm_colorMaterialChange = gc->light.back.colorMaterialChange;
|
|
|
|
if ((gc->state.enables.general & __GL_COLOR_MATERIAL_ENABLE) &&
|
|
msm_colorMaterialChange && (modeFlags & __GL_SHADE_RGB))
|
|
flags |= __GL_PHONG_NEED_COLOR_XPOLATE;
|
|
|
|
//Compute Invariant color if possible
|
|
if (((!(flags & __GL_PHONG_NEED_COLOR_XPOLATE) ||
|
|
!(msm_colorMaterialChange & (__GL_MATERIAL_AMBIENT |
|
|
__GL_MATERIAL_EMISSIVE))) &&
|
|
(modeFlags & __GL_SHADE_RGB)) &&
|
|
!(flags & __GL_PHONG_NEED_EYE_XPOLATE))
|
|
{
|
|
ComputePhongInvarientRGBColor (gc);
|
|
flags |= __GL_PHONG_INV_COLOR_VALID;
|
|
}
|
|
|
|
//Store the flags
|
|
gc->polygon.shader.phong.flags |= flags;
|
|
|
|
needColor = (gc->polygon.shader.phong.flags &
|
|
__GL_PHONG_NEED_COLOR_XPOLATE);
|
|
needEye = (gc->polygon.shader.phong.flags &
|
|
__GL_PHONG_NEED_EYE_XPOLATE);
|
|
|
|
#ifdef __GL_LINT
|
|
ccw = ccw;
|
|
#endif
|
|
/*
|
|
** Recompute the area of the triangle after constraining the incoming
|
|
** coordinates to the subpixel precision. The viewport bias gives
|
|
** more precision (typically) than the subpixel precision. Because of
|
|
** this the algorithim below can fail to reject an essentially empty
|
|
** triangle and instead fill a large area. The scan converter fill
|
|
** routines (eg polydraw.c) don't have this trouble because of the
|
|
** very nature of edge walking.
|
|
**
|
|
** NOTE: Notice that here as in other places, when the area calculation
|
|
** is done we are careful to do it as a series of subtractions followed by
|
|
** multiplications. This is done to guarantee that no overflow will
|
|
** occur (remember that the coordinates are biased by a potentially large
|
|
** number, and that multiplying two biased numbers will square the bias).
|
|
*/
|
|
ax = __GL_FIX_PRECISION(a->window.x);
|
|
bx = __GL_FIX_PRECISION(b->window.x);
|
|
cx = __GL_FIX_PRECISION(c->window.x);
|
|
ay = __GL_FIX_PRECISION(a->window.y);
|
|
by = __GL_FIX_PRECISION(b->window.y);
|
|
cy = __GL_FIX_PRECISION(c->window.y);
|
|
area = (ax - cx) * (by - cy) - (bx - cx) * (ay - cy);
|
|
if (area == zero) {
|
|
return;
|
|
}
|
|
|
|
na = &a->normal;
|
|
nb = &b->normal;
|
|
nc = &c->normal;
|
|
|
|
if (needColor)
|
|
{
|
|
ca = a->color;
|
|
cb = b->color;
|
|
cc = c->color;
|
|
flatColor = gc->vertex.provoking->color;
|
|
}
|
|
|
|
if (needEye)
|
|
{
|
|
ea.x = a->eyeX; ea.y = a->eyeY; ea.z = a->eyeZ; ea.w = a->eyeW;
|
|
eb.x = b->eyeX; eb.y = b->eyeY; eb.z = b->eyeZ; eb.w = b->eyeW;
|
|
ec.x = c->eyeX; ec.y = c->eyeY; ec.z = c->eyeZ; ec.w = c->eyeW;
|
|
}
|
|
|
|
|
|
/*
|
|
** Construct plane equations for all of the parameters that are
|
|
** computed for the triangle: z, r, g, b, a, s, t, f
|
|
*/
|
|
if (modeFlags & __GL_SHADE_DEPTH_ITER)
|
|
{
|
|
FindPlaneEquation(&zp, a, b, c, a->window.z, b->window.z,
|
|
c->window.z);
|
|
}
|
|
|
|
#ifdef GL_WIN_specular_fog
|
|
if (modeFlags & __GL_SHADE_COMPUTE_FOG)
|
|
{
|
|
FindPlaneEquation(&ezp, a, b, c, a->eyeZ, b->eyeZ, c->eyeZ);
|
|
}
|
|
else if (modeFlags & __GL_SHADE_INTERP_FOG)
|
|
{
|
|
__GLfloat aFog = 1.0f, bFog = 1.0f, cFog = 1.0f;
|
|
|
|
if (gc->polygon.shader.modeFlags & __GL_SHADE_SPEC_FOG)
|
|
{
|
|
aFog = ComputeSpecValue (gc, a);
|
|
bFog = ComputeSpecValue (gc, b);
|
|
cFog = ComputeSpecValue (gc, c);
|
|
}
|
|
|
|
if (gc->polygon.shader.modeFlags & __GL_SHADE_SLOW_FOG)
|
|
{
|
|
aFog *= a->fog;
|
|
bFog *= b->fog;
|
|
cFog *= c->fog;
|
|
}
|
|
|
|
FindPlaneEquation(&fp, a, b, c, aFog, bFog, cFog);
|
|
}
|
|
#else //GL_WIN_specular_fog
|
|
if (modeFlags & __GL_SHADE_SLOW_FOG)
|
|
{
|
|
FindPlaneEquation(&ezp, a, b, c, a->eyeZ, b->eyeZ, c->eyeZ);
|
|
}
|
|
else if (modeFlags & __GL_SHADE_INTERP_FOG)
|
|
{
|
|
FindPlaneEquation(&fp, a, b, c, a->fog, b->fog, c->fog);
|
|
}
|
|
#endif //GL_WIN_specular_fog
|
|
|
|
if (modeFlags & __GL_SHADE_TEXTURE)
|
|
{
|
|
__GLfloat one = __glOne;
|
|
__GLfloat aWInv = a->window.w;
|
|
__GLfloat bWInv = b->window.w;
|
|
__GLfloat cWInv = c->window.w;
|
|
FindPlaneEquation(&qwp, a, b, c, a->texture.w * aWInv,
|
|
b->texture.w * bWInv, c->texture.w * cWInv);
|
|
FindPlaneEquation(&sp, a, b, c, a->texture.x * aWInv,
|
|
b->texture.x * bWInv, c->texture.x * cWInv);
|
|
FindPlaneEquation(&tp, a, b, c, a->texture.y * aWInv,
|
|
b->texture.y * bWInv, c->texture.y * cWInv);
|
|
}
|
|
|
|
rgbMode = gc->modes.rgbMode;
|
|
|
|
if (needColor)
|
|
{
|
|
if (modeFlags & __GL_SHADE_SMOOTH) {
|
|
FindPlaneEquation(&rp, a, b, c, ca->r, cb->r, cc->r);
|
|
if (rgbMode) {
|
|
FindPlaneEquation(&gp, a, b, c, ca->g, cb->g, cc->g);
|
|
FindPlaneEquation(&bp, a, b, c, ca->b, cb->b, cc->b);
|
|
FindPlaneEquation(&ap, a, b, c, ca->a, cb->a, cc->a);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (needEye)
|
|
{
|
|
FindPlaneEquation(&exp, a, b, c, ea.x, eb.x, ec.x);
|
|
FindPlaneEquation(&eyp, a, b, c, ea.y, eb.y, ec.y);
|
|
// FindPlaneEquation(&ezp, a, b, c, ea.z, eb.z, ec.z);
|
|
FindPlaneEquation(&ewp, a, b, c, ea.w, eb.w, ec.w);
|
|
}
|
|
|
|
FindPlaneEquation(&nxp, a, b, c, na->x, nb->x, nc->x);
|
|
FindPlaneEquation(&nyp, a, b, c, na->y, nb->y, nc->y);
|
|
FindPlaneEquation(&nzp, a, b, c, na->z, nb->z, nc->z);
|
|
|
|
/*
|
|
** Compute general form of the line equations for each of the
|
|
** edges of the triangle.
|
|
*/
|
|
FindLineEqation(&tm.ab, a, b, c);
|
|
FindLineEqation(&tm.bc, b, c, a);
|
|
FindLineEqation(&tm.ca, c, a, b);
|
|
|
|
/* Compute bounding box of the triangle */
|
|
left = (GLint)a->window.x;
|
|
if (b->window.x < left) left = (GLint)b->window.x;
|
|
if (c->window.x < left) left = (GLint)c->window.x;
|
|
right = (GLint)a->window.x;
|
|
if (b->window.x > right) right = (GLint)b->window.x;
|
|
if (c->window.x > right) right = (GLint)c->window.x;
|
|
bottom = (GLint)a->window.y;
|
|
if (b->window.y < bottom) bottom = (GLint)b->window.y;
|
|
if (c->window.y < bottom) bottom = (GLint)c->window.y;
|
|
top = (GLint)a->window.y;
|
|
if (b->window.y > top) top = (GLint)b->window.y;
|
|
if (c->window.y > top) top = (GLint)c->window.y;
|
|
|
|
/* Bloat the bounding box when anti aliasing */
|
|
left -= (GLint)FILTER_WIDTH;
|
|
right += (GLint)FILTER_WIDTH;
|
|
bottom -= (GLint)FILTER_HEIGHT;
|
|
top += (GLint)FILTER_HEIGHT;
|
|
|
|
/* Init coverage computations */
|
|
samples = (gc->state.hints.polygonSmooth == GL_NICEST) ? 8 : 4;
|
|
ComputeCoverageStuff(&cs, samples);
|
|
|
|
/* Scan over the bounding box of the triangle */
|
|
for (y = bottom; y <= top; y++)
|
|
{
|
|
cs.lastCoverageWasOne = GL_FALSE;
|
|
for (x = left; x <= right; x++)
|
|
{
|
|
__GLfloat coverage;
|
|
__GLfloat xs, ys;
|
|
|
|
if (modeFlags & __GL_SHADE_STIPPLE)
|
|
{
|
|
/*
|
|
** Check the window coordinate against the stipple and
|
|
** and see if the pixel can be written
|
|
*/
|
|
GLint row = y & 31;
|
|
GLint col = x & 31;
|
|
if ((gc->polygon.stipple[row] & (1<<col)) == 0)
|
|
{
|
|
/*
|
|
** Stipple bit is clear. Do not render this pixel
|
|
** of the triangle.
|
|
*/
|
|
continue;
|
|
}
|
|
}
|
|
|
|
xs = x + __glHalf; /* sample point is at pixel center */
|
|
ys = y + __glHalf;
|
|
coverage = Coverage(&tm, &xs, &ys, &cs);
|
|
if (coverage != zero)
|
|
{
|
|
__GLfragment frag;
|
|
/*
|
|
** Fill in fragment for rendering. First compute the color
|
|
** of the fragment.
|
|
*/
|
|
phong->nTmp.x = FindP(&nxp, xs, ys);
|
|
phong->nTmp.y = FindP(&nyp, xs, ys);
|
|
phong->nTmp.z = FindP(&nzp, xs, ys);
|
|
|
|
if (needColor)
|
|
{
|
|
phong->tmpColor.r = FindP(&rp, xs, ys);
|
|
if (modeFlags & __GL_SHADE_RGB)
|
|
{
|
|
phong->tmpColor.g = FindP(&gp, xs, ys);
|
|
phong->tmpColor.b = FindP(&bp, xs, ys);
|
|
phong->tmpColor.a = FindP(&ap, xs, ys);
|
|
}
|
|
}
|
|
|
|
if (needEye)
|
|
{
|
|
phong->eTmp.x = FindP(&exp, xs, ys);
|
|
phong->eTmp.y = FindP(&eyp, xs, ys);
|
|
phong->eTmp.z = FindP(&ezp, xs, ys);
|
|
phong->eTmp.w = FindP(&ewp, xs, ys);
|
|
}
|
|
|
|
|
|
if (modeFlags & __GL_SHADE_RGB)
|
|
(*gc->procs.phong.ComputeRGBColor) (gc, &(frag.color));
|
|
else
|
|
(*gc->procs.phong.ComputeCIColor) (gc, &(frag.color));
|
|
|
|
/*
|
|
** Texture the fragment.
|
|
*/
|
|
if (modeFlags & __GL_SHADE_TEXTURE) {
|
|
__GLfloat qw, s, t, rho;
|
|
|
|
qw = FindP(&qwp, xs, ys);
|
|
s = FindP(&sp, xs, ys);
|
|
t = FindP(&tp, xs, ys);
|
|
rho = (*gc->procs.calcPolygonRho)(gc, sh, s, t, qw);
|
|
if( qw == (__GLfloat) 0.0 )
|
|
s = t = (__GLfloat) 0;
|
|
else {
|
|
s /= qw;
|
|
t /= qw;
|
|
}
|
|
(*gc->procs.texture)(gc, &frag.color, s, t, rho);
|
|
}
|
|
|
|
/*
|
|
** Fog the resulting color.
|
|
*/
|
|
if (modeFlags & __GL_SHADE_COMPUTE_FOG)
|
|
{
|
|
__GLfloat eyeZ = FindP(&ezp, xs, ys);
|
|
__glFogFragmentSlow(gc, &frag, eyeZ);
|
|
}
|
|
else if (modeFlags & __GL_SHADE_INTERP_FOG)
|
|
{
|
|
__GLfloat fog = FindP(&fp, xs, ys);
|
|
__glFogColorSlow(gc, &(frag.color), &(frag.color), fog);
|
|
}
|
|
|
|
/*
|
|
** Apply anti-aliasing effect
|
|
*/
|
|
if (rgbMode) {
|
|
frag.color.a *= coverage;
|
|
} else {
|
|
frag.color.r =
|
|
__glBuildAntiAliasIndex(frag.color.r,
|
|
coverage);
|
|
}
|
|
|
|
/*
|
|
** Finally, render the fragment.
|
|
*/
|
|
frag.x = (GLint)xs;
|
|
frag.y = (GLint)ys;
|
|
if (modeFlags & __GL_SHADE_DEPTH_ITER) {
|
|
frag.z = (__GLzValue)FindP(&zp, xs, ys);
|
|
}
|
|
(*gc->procs.store)(cfb, &frag);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
#endif //GL_WIN_phong_shading
|