// shadow.cpp: stencil shadow rendering
#include "cube.h"
VARP(stencilshadow, 0, 40, 100);
int stenciling = 0;
VAR(shadowclip, 0, 1, 1);
VAR(shadowtile, 0, 1, 1);
const int dbgtiles = 0;
//VAR(dbgtiles, 0, 0, 1);
VAR(shadowcasters, 1, 0, 0);
#define SHADOWROWS 64
#define SHADOWCOLUMNS 32
#define SHADOWCOLUMNMASK (0xFFFFFFFFU>>(32-SHADOWCOLUMNS))
uint shadowtiles[SHADOWROWS+1];
float shadowx1 = 1, shadowy1 = 1, shadowx2 = -1, shadowy2 = -1;
static void extrudeshadowtiles(int x1, int y1, int x2, int y2, int x3, int y3)
{
if(y1 > y2) { swap(x1, x2); swap(y1, y2); }
if(y2 > y3) { swap(x2, x3); swap(y2, y3); }
if(y1 > y2) { swap(x1, x2); swap(y1, y2); }
if(y3 < 0 || y1 >= SHADOWROWS) return;
int lx = x1, rx = x1,
fracl = 0, fracr = 0,
dlx, dly, drx, dry;
if(x2 <= x3) { dlx = x2; dly = y2; drx = x3; dry = y3; }
else { dlx = x3; dly = y3; drx = x2; dry = y2; }
dlx -= x1; dly -= y1;
drx -= x1; dry -= y1;
int ldir = 1, rdir = 1;
if(dlx < 0)
{
ldir = -1;
dlx = -dlx;
}
if(drx < 0)
{
rdir = -1;
drx = -drx;
}
int cy = y1;
y2 = min(y2, SHADOWROWS);
if(cy < 0 && y2 > cy)
{
int dy = min(y2, 0) - cy;
cy += dy;
fracl += dy*dlx;
lx += ldir*(fracl/dly);
fracl %= dly;
fracr += dy*drx;
rx += rdir*(fracr/dry);
fracr %= dry;
}
for(; cy < y2; cy++)
{
int cx1 = lx, cx2 = rx;
fracl += dlx;
while(fracl >= dly) { lx += ldir; if(ldir < 0) cx1 = lx; fracl -= dly; }
fracr += drx;
while(fracr >= dry) { rx += rdir; if(rdir > 0) cx2 = rx; fracr -= dry; }
if(cx1 < SHADOWCOLUMNS && cx2 >= 0) shadowtiles[cy] |= (SHADOWCOLUMNMASK>>(SHADOWCOLUMNS - (min(cx2, SHADOWCOLUMNS-1)+1))) & (SHADOWCOLUMNMASK<<max(cx1, 0));
}
if(cy >= SHADOWROWS) return;
if(x2 < x3 || y1 == cy)
{
if(x2 < lx) lx = x2;
dlx = x3 - lx; dly = y3 - cy;
ldir = 1;
if(dlx < 0)
{
ldir = -1;
dlx = -dlx;
}
fracl = 0;
}
if(x2 > x3 || y1 == cy)
{
if(x2 > rx) rx = x2;
drx = x3 - rx; dry = y3 - cy;
rdir = 1;
if(drx < 0)
{
rdir = -1;
drx = -drx;
}
fracr = 0;
}
y3 = min(y3, SHADOWROWS);
if(cy < 0 && y3 > cy)
{
int dy = min(y3, 0) - cy;
cy += dy;
fracl += dy*dlx;
lx += ldir*(fracl/dly);
fracl %= dly;
fracr += dy*drx;
rx += rdir*(fracr/dry);
fracr %= dry;
}
for(; cy < y3; cy++)
{
int cx1 = lx, cx2 = rx;
fracl += dlx;
while(fracl >= dly) { lx += ldir; if(ldir < 0) cx1 = lx; fracl -= dly; }
fracr += drx;
while(fracr >= dry) { rx += rdir; if(rdir > 0) cx2 = rx; fracr -= dry; }
if(cx1 < SHADOWCOLUMNS && cx2 >= 0) shadowtiles[cy] |= (SHADOWCOLUMNMASK>>(SHADOWCOLUMNS - (min(cx2, SHADOWCOLUMNS-1)+1))) & (SHADOWCOLUMNMASK<<max(cx1, 0));
}
if(cy < SHADOWROWS)
{
int cx1 = lx, cx2 = rx;
if(dly)
{
fracl += dlx;
while(fracl >= dly) { lx += ldir; if(ldir < 0) cx1 = lx; fracl -= dly; }
}
if(dry)
{
fracr += drx;
while(fracr >= dry) { rx += rdir; if(rdir > 0) cx2 = rx; fracr -= dry; }
}
if(cx1 < SHADOWCOLUMNS && cx2 >= 0) shadowtiles[cy] |= (SHADOWCOLUMNMASK>>(SHADOWCOLUMNS - (min(cx2, SHADOWCOLUMNS-1)+1))) & (SHADOWCOLUMNMASK<<max(cx1, 0));
}
}
static void addshadowtiles(float x1, float y1, float x2, float y2)
{
shadowx1 = min(shadowx1, x1);
shadowy1 = min(shadowy1, y1);
shadowx2 = max(shadowx2, x2);
shadowy2 = max(shadowy2, y2);
int tx1 = clamp(int(floor((y1 + 1)/2 * SHADOWCOLUMNS)), 0, SHADOWCOLUMNS - 1),
ty1 = clamp(int(floor((x1 + 1)/2 * SHADOWROWS)), 0, SHADOWROWS - 1),
tx2 = clamp(int(floor((y2 + 1)/2 * SHADOWCOLUMNS)), 0, SHADOWCOLUMNS - 1),
ty2 = clamp(int(floor((x2 + 1)/2 * SHADOWROWS)), 0, SHADOWROWS - 1);
uint mask = (SHADOWCOLUMNMASK>>(SHADOWCOLUMNS - (tx2+1))) & (SHADOWCOLUMNMASK<<tx1);
for(int y = ty1; y <= ty2; y++) shadowtiles[y] |= mask;
}
bool addshadowbox(const vec &bbmin, const vec &bbmax, const vec &extrude, const glmatrixf &mat)
{
vec4 v[8];
float sx1 = 1e16f, sy1 = 1e16f, sx2 = -1e16f, sy2 = -1e16f;
int front = 0;
loopi(8)
{
vec4 &p = v[i];
mat.transform(vec(i&1 ? bbmax.x : bbmin.x, i&2 ? bbmax.y : bbmin.y, i&4 ? bbmax.z : bbmin.z), p);
if(p.z >= -p.w)
{
float x = p.x / p.w, y = p.y / p.w;
sx1 = min(sx1, x);
sy1 = min(sy1, y);
sx2 = max(sx2, x);
sy2 = max(sy2, y);
front++;
}
}
vec4 ev;
mat.transform(extrude, ev);
if(ev.z < -ev.w && !front) return false;
if(front < 8 || ev.z < -ev.w) loopi(8)
{
const vec4 &p = v[i];
if(p.z >= -p.w)
{
if(ev.z >= -ev.w) continue;
float t = ev.z/(ev.z - p.z),
w = ev.w + t*(p.w - ev.w),
x = (ev.x + t*(p.x - ev.x))/w,
y = (ev.y + t*(p.y - ev.y))/w;
sx1 = min(sx1, x);
sy1 = min(sy1, y);
sx2 = max(sx2, x);
sy2 = max(sy2, y);
continue;
}
loopj(3)
{
const vec4 &o = v[i^(1<<j)];
if(o.z < -o.w) continue;
float t = p.z/(p.z - o.z),
w = p.w + t*(o.w - p.w),
x = (p.x + t*(o.x - p.x))/w,
y = (p.y + t*(o.y - p.y))/w;
sx1 = min(sx1, x);
sy1 = min(sy1, y);
sx2 = max(sx2, x);
sy2 = max(sy2, y);
}
if(ev.z < -ev.w) continue;
float t = p.z/(p.z - ev.z),
w = p.w + t*(ev.w - p.w),
x = (p.x + t*(ev.x - p.x))/w,
y = (p.y + t*(ev.y - p.y))/w;
sx1 = min(sx1, x);
sy1 = min(sy1, y);
sx2 = max(sx2, x);
sy2 = max(sy2, y);
}
if(ev.z >= -ev.w)
{
float x = ev.x/ev.w, y = ev.y/ev.w;
if((sx1 >= 1 && x >= 1) || (sy1 >= 1 && y >= 1) || (sx2 <= -1 && x <= -1) || (sy2 <= -1 && y <= -1)) return false;
int tx = int(floor(SHADOWCOLUMNS * (y + 1) / 2)), ty = int(floor(SHADOWROWS * (x + 1) / 2)),
tx1 = int(floor(SHADOWCOLUMNS * (sy1 + 1) / 2)), ty1 = int(floor(SHADOWROWS * (sx1 + 1) / 2)),
tx2 = int(floor(SHADOWCOLUMNS * (sy2 + 1) / 2)), ty2 = int(floor(SHADOWROWS * (sx2 + 1) / 2));
if(tx < tx1)
{
if(ty < ty1) { swap(ty1, ty2); tx1--; ty1--; }
else if(ty > ty2) { tx1--; ty1++; }
else { tx2 = tx1; tx1--; tx2--; }
}
else if(tx > tx2)
{
if(ty < ty1) { ty1--; tx2++; }
else if(ty > ty2) { swap(ty1, ty2); ty1++; tx2++; }
else { tx1 = tx2; tx1++; tx2++; }
}
else
{
if(ty < ty1) { ty2 = ty1; ty1--; ty2--; }
else if(ty > ty2) { ty1 = ty2; ty1++; ty2++; }
else goto noextrusion;
}
extrudeshadowtiles(tx, ty, tx1, ty1, tx2, ty2);
shadowx1 = min(x, shadowx1);
shadowy1 = min(y, shadowy1);
shadowx2 = max(x, shadowx2);
shadowy2 = max(y, shadowy2);
noextrusion:;
}
else if(sx1 >= 1 || sy1 >= 1 || sx2 <= -1 || sy2 <= -1) return false;
shadowcasters++;
addshadowtiles(sx1, sy1, sx2, sy2);
return true;
}
static void rendershadowtiles()
{
shadowx1 = clamp(shadowx1, -1.0f, 1.0f);
shadowy1 = clamp(shadowy1, -1.0f, 1.0f);
shadowx2 = clamp(shadowx2, -1.0f, 1.0f);
shadowy2 = clamp(shadowy2, -1.0f, 1.0f);
if(shadowx1 >= shadowx2 || shadowy1 >= shadowy2) return;
float clipx1 = (shadowy1 + 1) / 2,
clipy1 = (shadowx1 + 1) / 2,
clipx2 = (shadowy2 + 1) / 2,
clipy2 = (shadowx2 + 1) / 2;
if(!shadowclip)
{
clipx1 = clipy1 = 0;
clipx2 = clipy2 = 1;
}
if(!shadowtile)
{
glBegin(GL_TRIANGLE_STRIP);
glVertex2f(clipy1, clipx1);
glVertex2f(clipy1, clipx2);
glVertex2f(clipy2, clipx1);
glVertex2f(clipy2, clipx2);
xtraverts += 4;
glEnd();
return;
}
glBegin(GL_QUADS);
float tw = 1.0f/SHADOWCOLUMNS, th = 1.0f/SHADOWROWS;
loop(y, SHADOWROWS+1)
{
uint mask = shadowtiles[y];
int x = 0;
while(mask)
{
while(!(mask&0xFF)) { mask >>= 8; x += 8; }
while(!(mask&1)) { mask >>= 1; x++; }
int xstart = x;
do { mask >>= 1; x++; } while(mask&1);
uint strip = (SHADOWCOLUMNMASK>>(SHADOWCOLUMNS - x)) & (SHADOWCOLUMNMASK<<xstart);
int yend = y;
do { shadowtiles[yend] &= ~strip; yend++; } while((shadowtiles[yend] & strip) == strip);
float vx = xstart*tw,
vy = y*th,
vw = (x-xstart)*tw,
vh = (yend-y)*th,
vx1 = max(vx, clipx1),
vy1 = max(vy, clipy1),
vx2 = min(vx+vw, clipx2),
vy2 = min(vy+vh, clipy2);
glVertex2f(vy1, vx1);
glVertex2f(vy1, vx2);
glVertex2f(vy2, vx2);
glVertex2f(vy2, vx1);
xtraverts += 4;
}
}
glEnd();
}
void drawstencilshadows()
{
glDisable(GL_FOG);
glEnable(GL_STENCIL_TEST);
glDisable(GL_TEXTURE_2D);
glDepthMask(GL_FALSE);
glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
stenciling = 1;
shadowcasters = 0;
shadowx2 = shadowy2 = -1;
shadowx1 = shadowy1 = 1;
memset(shadowtiles, 0, sizeof(shadowtiles));
if(hasST2 || hasSTS)
{
glDisable(GL_CULL_FACE);
if(hasST2)
{
glEnable(GL_STENCIL_TEST_TWO_SIDE_EXT);
glActiveStencilFace_(GL_BACK);
glStencilFunc(GL_ALWAYS, 0, ~0U);
glStencilOp(GL_KEEP, GL_KEEP, hasSTW ? GL_INCR_WRAP_EXT : GL_INCR);
glActiveStencilFace_(GL_FRONT);
glStencilFunc(GL_ALWAYS, 0, ~0U);
glStencilOp(GL_KEEP, GL_KEEP, hasSTW ? GL_DECR_WRAP_EXT : GL_DECR);
}
else
{
glStencilFuncSeparate_(GL_ALWAYS, GL_ALWAYS, 0, ~0U);
glStencilOpSeparate_(GL_BACK, GL_KEEP, GL_KEEP, hasSTW ? GL_INCR_WRAP_EXT : GL_INCR);
glStencilOpSeparate_(GL_FRONT, GL_KEEP, GL_KEEP, hasSTW ? GL_DECR_WRAP_EXT : GL_DECR);
}
startmodelbatches();
rendermapmodels();
renderentities();
renderclients();
renderbounceents();
endmodelbatches();
if(hasST2) glDisable(GL_STENCIL_TEST_TWO_SIDE_EXT);
glEnable(GL_CULL_FACE);
}
else
{
glStencilFunc(GL_ALWAYS, 0, ~0U);
glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
startmodelbatches();
rendermapmodels();
renderentities();
renderclients();
renderbounceents();
endmodelbatches(false);
if(shadowcasters)
{
stenciling = 2;
glStencilFunc(GL_ALWAYS, 0, ~0U);
glStencilOp(GL_KEEP, GL_KEEP, GL_DECR);
glCullFace(GL_BACK);
endmodelbatches(true);
glCullFace(GL_FRONT);
}
else clearmodelbatches();
}
stenciling = 0;
glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
glDepthMask(GL_TRUE);
if(shadowcasters)
{
glDisable(GL_DEPTH_TEST);
glStencilFunc(GL_NOTEQUAL, (hasST2 || hasSTS) && !hasSTW ? 128 : 0, ~0U);
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glEnable(GL_BLEND);
glBlendFunc(GL_ZERO, GL_SRC_COLOR);
float intensity = 1.0f - stencilshadow/100.0f;
glColor3f(intensity, intensity, intensity);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 1, 0, 1, -1, 1);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
static uint debugtiles[SHADOWROWS+1];
if(dbgtiles) memcpy(debugtiles, shadowtiles, sizeof(debugtiles));
rendershadowtiles();
if(dbgtiles)
{
glDisable(GL_STENCIL_TEST);
glColor3f(0.5f, 1, 0.5f);
memcpy(shadowtiles, debugtiles, sizeof(debugtiles));
rendershadowtiles();
glColor3f(0, 0, 1);
glDisable(GL_BLEND);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
memcpy(shadowtiles, debugtiles, sizeof(debugtiles));
rendershadowtiles();
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}
else glDisable(GL_BLEND);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
setperspective(fovy, 0.15f);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glEnable(GL_DEPTH_TEST);
}
// necessary to avoid ATI bug!
// punts to software mode if separate stencil op is set, even while stencil disabled, when drawing lines!
glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
glDisable(GL_STENCIL_TEST);
glEnable(GL_TEXTURE_2D);
glEnable(GL_FOG);
}
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Shadow.cpp
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