94 lines
2.5 KiB
GLSL
94 lines
2.5 KiB
GLSL
// animated SWWM GZ logo
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#define overlay(a,b) (a<0.5)?(2.0*a*b):(1.0-(2.0*(1.0-a)*(1.0-b)))
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const float pi = 3.14159265358979323846;
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vec2 warpcoord( in vec2 uv )
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{
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vec2 offset;
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offset.y = sin(pi*2.*(uv.x*8.+timer*.25))*.005;
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offset.x = cos(pi*2.*(uv.y*4.+timer*.25))*.005;
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return uv+offset;
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}
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// based on gimp color to alpha, but simplified
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vec4 blacktoalpha( in vec4 src )
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{
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vec4 dst = src;
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float alpha = 0.;
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float a;
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a = clamp(dst.r,0.,1.);
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if ( a > alpha ) alpha = a;
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a = clamp(dst.g,0.,1.);
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if ( a > alpha ) alpha = a;
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a = clamp(dst.b,0.,1.);
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if ( a > alpha ) alpha = a;
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if ( alpha > 0. )
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{
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float ainv = 1./alpha;
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dst.rgb *= ainv;
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}
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dst.a *= alpha;
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return dst;
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}
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#ifdef NO_BILINEAR
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#define BilinearSample(x,y,z,w) texture(x,y)
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#else
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vec4 BilinearSample( in sampler2D tex, in vec2 pos, in vec2 size, in vec2 pxsize )
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{
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vec2 f = fract(pos*size);
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pos += (.5-f)*pxsize;
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vec4 p0q0 = texture(tex,pos);
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vec4 p1q0 = texture(tex,pos+vec2(pxsize.x,0));
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vec4 p0q1 = texture(tex,pos+vec2(0,pxsize.y));
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vec4 p1q1 = texture(tex,pos+vec2(pxsize.x,pxsize.y));
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vec4 pInterp_q0 = mix(p0q0,p1q0,f.x);
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vec4 pInterp_q1 = mix(p0q1,p1q1,f.x);
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return mix(pInterp_q0,pInterp_q1,f.y);
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}
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#endif
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void SetupMaterial( inout Material mat )
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{
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// store these to save some time
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vec2 size = vec2(textureSize(Layer1,0));
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vec2 pxsize = 1./size;
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// y'all ready for this multilayered madness?
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vec2 uv = vTexCoord.st;
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// base blank layer
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vec4 base = vec4(0.,0.,0.,1.);
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// first layer, blend
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vec4 tmp = BilinearSample(Layer1,uv,size,pxsize);
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base.rgb = mix(base.rgb,tmp.rgb,tmp.a);
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// second layer, warp then add
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tmp = BilinearSample(Layer2,warpcoord(uv),size,pxsize);
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base.rgb += tmp.rgb;
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// third layer, multiply
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tmp = BilinearSample(Layer3,uv,size,pxsize);
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base.rgb *= tmp.rgb;
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// fourth layer, add
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tmp = BilinearSample(Layer4,uv,size,pxsize);
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base.rgb += tmp.rgb;
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// fifth layer, add
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tmp = BilinearSample(Layer5,uv,size,pxsize);
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base.rgb += tmp.rgb;
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// first layer again, overlay (w/ alpha blend)
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tmp = BilinearSample(Layer1,uv,size,pxsize);
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vec4 tmp2;
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tmp2.r = overlay(base.r,tmp.r);
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tmp2.g = overlay(base.g,tmp.g);
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tmp2.b = overlay(base.b,tmp.b);
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base.rgb = mix(base.rgb,tmp2.rgb,tmp.a);
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// black to alpha
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base = blacktoalpha(base);
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// add alpha of first layer
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base.a += BilinearSample(Layer1,uv,size,pxsize).a;
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// sixth layer, alpha blend
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tmp = BilinearSample(Layer6,uv,size,pxsize);
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tmp2.a = tmp.a+base.a*(1-tmp.a);
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tmp2.rgb = (tmp.rgb*tmp.a+base.rgb*base.a*(1-tmp.a))/tmp2.a;
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// clamp
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tmp2 = clamp(tmp2,vec4(0.),vec4(1.));
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// ding, logo's done
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mat.Base = tmp2;
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}
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