121 lines
3.9 KiB
C++
121 lines
3.9 KiB
C++
#define MAXLIGHTNINGSTEPS 64
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#define LIGHTNINGSTEP 8
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int lnjitterx[2][MAXLIGHTNINGSTEPS], lnjittery[2][MAXLIGHTNINGSTEPS];
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int lnjitterframe = 0, lastlnjitter = 0;
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VAR(lnjittermillis, 0, 100, 1000);
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VAR(lnjitterradius, 0, 4, 100);
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FVAR(lnjitterscale, 0, 0.5f, 10);
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VAR(lnscrollmillis, 1, 300, 5000);
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FVAR(lnscrollscale, 0, 0.125f, 10);
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FVAR(lnblendpower, 0, 0.25f, 1000);
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static void calclightningjitter(int frame)
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{
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loopi(MAXLIGHTNINGSTEPS)
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{
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lnjitterx[lnjitterframe][i] = -lnjitterradius + rnd(2*lnjitterradius + 1);
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lnjittery[lnjitterframe][i] = -lnjitterradius + rnd(2*lnjitterradius + 1);
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}
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}
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static void setuplightning()
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{
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if(!lastlnjitter || lastmillis-lastlnjitter > lnjittermillis)
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{
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if(!lastlnjitter) calclightningjitter(lnjitterframe);
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lastlnjitter = lastmillis - (lastmillis%lnjittermillis);
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calclightningjitter(lnjitterframe ^= 1);
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}
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}
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static void renderlightning(Texture *tex, const vec &o, const vec &d, float sz)
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{
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vec step(d);
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step.sub(o);
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float len = step.magnitude();
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int numsteps = std::clamp(int(ceil(len/LIGHTNINGSTEP)), 2, MAXLIGHTNINGSTEPS);
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step.div(numsteps+1);
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int jitteroffset = detrnd(int(d.x+d.y+d.z), MAXLIGHTNINGSTEPS);
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vec cur(o), up, right;
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up.orthogonal(step);
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up.normalize();
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right.cross(up, step);
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right.normalize();
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float scroll = -float(lastmillis%lnscrollmillis)/lnscrollmillis,
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scrollscale = lnscrollscale*(LIGHTNINGSTEP*tex->ys)/(sz*tex->xs),
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blend = pow(std::clamp(float(lastmillis - lastlnjitter)/lnjittermillis, 0.0f, 1.0f), lnblendpower),
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jitter0 = (1-blend)*lnjitterscale*sz/lnjitterradius, jitter1 = blend*lnjitterscale*sz/lnjitterradius;
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gle::begin(GL_TRIANGLE_STRIP);
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loopj(numsteps)
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{
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vec next(cur);
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next.add(step);
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if(j+1==numsteps) next = d;
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else
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{
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int lj = (j+jitteroffset)%MAXLIGHTNINGSTEPS;
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next.add(vec(right).mul((jitter1*lnjitterx[lnjitterframe][lj] + jitter0*lnjitterx[lnjitterframe^1][lj])));
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next.add(vec(up).mul((jitter1*lnjittery[lnjitterframe][lj] + jitter0*lnjittery[lnjitterframe^1][lj])));
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}
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vec dir1 = next, dir2 = next, across;
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dir1.sub(cur);
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dir2.sub(camera1->o);
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across.cross(dir2, dir1).normalize().mul(sz);
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gle::attribf(cur.x-across.x, cur.y-across.y, cur.z-across.z);
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gle::attribf(scroll, 1);
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gle::attribf(cur.x+across.x, cur.y+across.y, cur.z+across.z);
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gle::attribf(scroll, 0);
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scroll += scrollscale;
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if(j+1==numsteps)
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{
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gle::attribf(next.x-across.x, next.y-across.y, next.z-across.z);
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gle::attribf(scroll, 1);
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gle::attribf(next.x+across.x, next.y+across.y, next.z+across.z);
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gle::attribf(scroll, 0);
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}
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cur = next;
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}
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gle::end();
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}
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struct lightningrenderer : listrenderer
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{
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lightningrenderer()
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: listrenderer("media/particle/lightning.jpg", 2, PT_LIGHTNING|PT_BRIGHT|PT_TRACK)
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{}
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void startrender()
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{
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setuplightning();
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glDisable(GL_CULL_FACE);
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gle::defattrib(gle::ATTRIB_VERTEX, 3, GL_FLOAT);
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gle::defattrib(gle::ATTRIB_TEXCOORD0, 2, GL_FLOAT);
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}
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void endrender()
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{
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glEnable(GL_CULL_FACE);
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}
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void seedemitter(particleemitter &pe, const vec &o, const vec &d, int fade, float size, int gravity)
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{
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pe.maxfade = max(pe.maxfade, fade);
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pe.extendbb(o, size);
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pe.extendbb(d, size);
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}
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void renderpart(listparticle *p, const vec &o, const vec &d, int blend, int ts)
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{
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blend = min(blend<<2, 255);
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if(type&PT_MOD) //multiply alpha into color
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gle::colorub((p->color.r*blend)>>8, (p->color.g*blend)>>8, (p->color.b*blend)>>8);
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else
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gle::color(p->color, blend);
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renderlightning(tex, o, d, p->size);
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}
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};
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static lightningrenderer lightnings;
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