100 lines
2.3 KiB
GLSL
100 lines
2.3 KiB
GLSL
#version 330
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// compatibility
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#define float4x4 mat4x4
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#define float4 vec4
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#define float3 vec3
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#define float2 vec2
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const float EPS = 0.001;
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const int MAX_ITER = 128;
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uniform vec2 u_resolution;
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out vec4 fragColor;
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struct sdQuery {
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float value;
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int obj_id;
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};
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float sdCube(vec3 p, vec3 b) {
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p = abs(p) - b;
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return length(max(p, 0.0)) + min(max(p.x, max(p.y, p.z)), 0.0);
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}
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float sdSphere(vec3 p, float r) {
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return length(p) - r;
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}
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float sdCappedCylinder( vec3 p, float r, float h )
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{
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vec2 d = abs(vec2(length(p.xz),p.y)) - vec2(r,h);
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return min(max(d.x,d.y),0.0) + length(max(d,0.0));
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}
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float sdVerticalCapsule( vec3 p, float h, float r )
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{
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p.y -= clamp( p.y, 0.0, h );
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return length( p ) - r;
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}
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float sdTorus( vec3 p, vec2 t )
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{
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vec2 q = vec2(length(p.xz)-t.x,p.y);
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return length(q)-t.y;
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}
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sdQuery sd(vec3 p) {
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sdQuery qry;
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qry.value = 100000000.0;
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qry.obj_id = -1;
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<SDF_BLOCK>
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return qry;
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}
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vec3 nrm(vec3 p) {
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vec2 d = vec2(EPS, 0.0);
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return normalize(vec3(
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sd(p + d.xyy).value - sd(p - d.xyy).value,
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sd(p + d.yxy).value - sd(p - d.yxy).value,
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sd(p + d.yyx).value - sd(p - d.yyx).value
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));
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}
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vec4 materialColor(int obj_id) {
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<COLOR_BLOCK>
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return vec4(1.0);
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}
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vec4 color(vec3 p, int obj_id) {
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vec3 normal = nrm(p);
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vec3 light_dir = normalize(vec3(0.5, 0.8, -0.6));
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float light = 0.2 + 0.8 * max(dot(normal, light_dir), 0.0);
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vec4 base = materialColor(obj_id);
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return vec4(base.rgb * light, base.a);
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}
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vec4 march(vec3 p, vec3 r) {
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sdQuery qry;
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vec4 col = vec4(0.0);
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for(int i = 0; i < MAX_ITER; ++i) {
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qry = sd(p);
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if(qry.value < EPS){
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col = color(p, qry.obj_id);
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break;
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}
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p += qry.value * r;
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}
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return col;
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}
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void main() {
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vec2 uv = 2. * (gl_FragCoord.xy / u_resolution - .5) * vec2(u_resolution.x / u_resolution.y, 1.);
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vec3 c_p = vec3(<CAM_POS>);
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vec3 c_z = normalize(vec3(<CAM_DIR>));
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vec3 world_up = abs(c_z.y) > 0.999 ? vec3(0., 0., 1.) : vec3(0., 1., 0.);
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vec3 c_x = normalize(cross(c_z, world_up));
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vec3 c_y = normalize(cross(c_x, c_z));
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mat3 view = mat3(c_x, c_y, c_z);
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vec3 r = normalize(vec3(uv, <CAM_FOCUS>));
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fragColor = march(c_p, view * r);
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}
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