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| 1 | +#version 460 |
| 2 | + |
| 3 | +#extension GL_EXT_samplerless_texture_functions : enable |
| 4 | + |
| 5 | +#include "scene.glsl" |
| 6 | +#include "common.glsl" |
| 7 | + |
| 8 | +layout(location = 0) out vec4 outColor; |
| 9 | + |
| 10 | +layout(location = 0) in flat uint axis; |
| 11 | +layout(location = 1) in flat float scale; |
| 12 | + |
| 13 | +layout(std140, push_constant) uniform Push { |
| 14 | + vec3 origin; |
| 15 | + }; |
| 16 | +layout(binding = 0, std140) uniform UboScene { |
| 17 | + SceneDesc scene; |
| 18 | + }; |
| 19 | +layout(binding = 1) uniform texture2D depth; |
| 20 | + |
| 21 | + |
| 22 | +float dot2(vec3 v) { return dot(v,v); } |
| 23 | + |
| 24 | +vec4 cylIntersect(vec3 ro, vec3 rd, vec3 a, vec3 b, float ra ) { |
| 25 | + vec3 ba = b - a; |
| 26 | + vec3 oc = ro - a; |
| 27 | + |
| 28 | + float baba = dot(ba,ba); |
| 29 | + float bard = dot(ba,rd); |
| 30 | + float baoc = dot(ba,oc); |
| 31 | + float k2 = baba - bard*bard; |
| 32 | + float k1 = baba*dot(oc,rd) - baoc*bard; |
| 33 | + float k0 = baba*dot(oc,oc) - baoc*baoc - ra*ra*baba; |
| 34 | + float h = k1*k1 - k2*k0; |
| 35 | + |
| 36 | + if( h<0.0 ) |
| 37 | + return vec4(-1.0);//no intersection |
| 38 | + h = sqrt(h); |
| 39 | + float t = (-k1-h)/k2; |
| 40 | + // body |
| 41 | + float y = baoc + t*bard; |
| 42 | + if( y>0.0 && y<baba ) |
| 43 | + return vec4((oc+t*rd - ba*y/baba)/ra, t); |
| 44 | + |
| 45 | + // caps |
| 46 | + t = ( ((y<0.0) ? 0.0 : baba) - baoc)/bard; |
| 47 | + if(abs(k1+k2*t) < h) |
| 48 | + return vec4(ba*sign(y)/sqrt(baba), t); |
| 49 | + |
| 50 | + return vec4(-1.0);//no intersection |
| 51 | + } |
| 52 | + |
| 53 | +vec4 coneIntersect(vec3 ro, vec3 rd, vec3 pa, vec3 pb, float ra, float rb) { |
| 54 | + vec3 ba = pb - pa; |
| 55 | + vec3 oa = ro - pa; |
| 56 | + vec3 ob = ro - pb; |
| 57 | + float m0 = dot(ba,ba); |
| 58 | + float m1 = dot(oa,ba); |
| 59 | + float m2 = dot(rd,ba); |
| 60 | + float m3 = dot(rd,oa); |
| 61 | + float m5 = dot(oa,oa); |
| 62 | + float m9 = dot(ob,ba); |
| 63 | + |
| 64 | + // caps |
| 65 | + if(m1 < 0.0) { |
| 66 | + if(dot2(oa*m2-rd*m1) < (ra*ra*m2*m2)) // delayed division |
| 67 | + return vec4(-ba*inversesqrt(m0), -m1/m2); |
| 68 | + } |
| 69 | + else if(m9 > 0.0) { |
| 70 | + float t = -m9/m2; // NOTE delayed division |
| 71 | + if(dot2(ob+rd*t) < (rb*rb)) |
| 72 | + return vec4(ba*inversesqrt(m0), t); |
| 73 | + } |
| 74 | + |
| 75 | + // body |
| 76 | + float rr = ra - rb; |
| 77 | + float hy = m0 + rr*rr; |
| 78 | + float k2 = m0*m0 - m2*m2*hy; |
| 79 | + float k1 = m0*m0*m3 - m1*m2*hy + m0*ra*(rr*m2*1.0 ); |
| 80 | + float k0 = m0*m0*m5 - m1*m1*hy + m0*ra*(rr*m1*2.0 - m0*ra); |
| 81 | + float h = k1*k1 - k2*k0; |
| 82 | + if(h < 0.0) |
| 83 | + return vec4(-1.0); //no intersection |
| 84 | + float t = (-k1-sqrt(h))/k2; |
| 85 | + float y = m1 + t*m2; |
| 86 | + if(y < 0.0 || y > m0) |
| 87 | + return vec4(-1.0); //no intersection |
| 88 | + return vec4(normalize(m0*(m0*(oa+t*rd)+rr*ba*ra)-ba*hy*y), t); |
| 89 | + } |
| 90 | + |
| 91 | +vec4 arrowIntersect(vec3 ro, vec3 rd) { |
| 92 | + vec3 off0 = vec3(0), off1 = vec3(0), off2 = vec3(0); |
| 93 | + off0[axis] = scale*10; |
| 94 | + off1[axis] = scale*160; |
| 95 | + off2[axis] = scale*200; |
| 96 | + |
| 97 | + vec4 body = cylIntersect (ro, rd, origin, origin + off1, 4.0 * scale); |
| 98 | + vec4 cap = coneIntersect(ro, rd, origin + off1, origin + off2, 10.0 * scale, 0); |
| 99 | + if(body.w>=0 && (body.w<cap.w || cap.w<=0)) |
| 100 | + return body; |
| 101 | + return cap; |
| 102 | + } |
| 103 | + |
| 104 | +void main() { |
| 105 | + const vec2 fragCoord = (gl_FragCoord.xy*scene.screenResInv)*2.0-vec2(1.0); |
| 106 | + const vec4 start4 = scene.viewProjectInv*vec4(fragCoord.x, fragCoord.y, 1.0, 1.0); |
| 107 | + const vec3 start = start4.xyz/start4.w; |
| 108 | + |
| 109 | + const vec3 camPos = scene.camPos; |
| 110 | + const vec3 view = normalize(start - camPos); |
| 111 | + |
| 112 | + const vec4 nort = arrowIntersect(camPos, view); |
| 113 | + if(nort.w>0) { |
| 114 | + vec3 clr = vec3(0); |
| 115 | + clr[axis] = 1; |
| 116 | + clr *= (max(0.0, dot(scene.sunDir, nort.xyz))*0.8 + 0.2); |
| 117 | + float d = texelFetch(depth, ivec2(gl_FragCoord.xy), 0).x; |
| 118 | + float dl = linearDepth(d, scene.clipInfo); |
| 119 | + if(nort.w > dl) { |
| 120 | + ivec2 id = ivec2(gl_FragCoord.xy)/4; |
| 121 | + clr *= (id.x+id.y)%2==0 ? 0.1 : 0.9; |
| 122 | + } |
| 123 | + outColor = vec4(clr,1); |
| 124 | + return; |
| 125 | + } |
| 126 | + |
| 127 | + discard; |
| 128 | + } |
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