161 lines
3.5 KiB
HLSL
161 lines
3.5 KiB
HLSL
// soft min of a and b with smoothing factor k
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float smin(float a, float b, float k) {
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float h = max(k - abs(a-b), 0) / k;
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return min(a, b) - h * h * h * k * (1 / 6.0);
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}
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// soft max of a and b with smoothing factor k
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float smax(float a, float b, float k) {
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float h = max(k - abs(a - b), 0) / k;
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return max(a, b) + h * h * h * k * (1 / 6.0);
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}
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Material mixMat(Material a, Material b, float fac) {
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Material m;
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fac = clamp(fac * 1.1 - 0.05, 0, 1); // TODO make this configurable, also possibly use smoothstep
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m.col = lerp(a.col, b.col, fac);
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m.gloss = lerp(a.gloss, b.gloss, fac);
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return m;
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}
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Material mixMat(SurfacePoint a, SurfacePoint b) {
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float fac = clamp(a.dist/(a.dist + b.dist), 0, 1);
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return mixMat(a.mat, b.mat, fac);
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}
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Material nearestMat(SurfacePoint a, SurfacePoint b) {
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if (a.dist < b.dist) {
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return a.mat;
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} else {
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return b.mat;
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}
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}
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// --------------------------------
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// base sdf operations
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// --------------------------------
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float qUnion(float a, float b) {
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return min(a, b);
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}
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float qUnion(float a, float b, float smooth) {
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return smin(a, b, smooth);
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}
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SurfacePoint qUnion(SurfacePoint a, SurfacePoint b) {
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SurfacePoint o;
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o.dist = min(a.dist, b.dist);
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o.mat = nearestMat(a, b);
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return o;
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}
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SurfacePoint qUnion(SurfacePoint a, SurfacePoint b, float smooth) {
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SurfacePoint o;
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o.dist = smin(a.dist, b.dist, smooth);
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o.mat = mixMat(a, b);
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return o;
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}
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float qSub(float a, float b) {
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return max(a, -b);
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}
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float qSub(float a, float b, float smooth) {
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return smax(a, -b, smooth);
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}
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SurfacePoint qSub(SurfacePoint a, SurfacePoint b) {
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SurfacePoint o;
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o.dist = max(a.dist, -b.dist);
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o.mat = a.mat;
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return o;
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}
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SurfacePoint qSub(SurfacePoint a, SurfacePoint b, float smooth) {
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SurfacePoint o;
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o.dist = smax(a.dist, -b.dist, smooth);
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o.mat = a.mat;
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return o;
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}
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float qIntersect(float a, float b) {
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return max(a, b);
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}
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float qIntersect(float a, float b, float smooth) {
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return smax(a, b, smooth);
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}
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SurfacePoint qIntersect(SurfacePoint a, SurfacePoint b) {
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SurfacePoint o;
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o.dist = max(a.dist, b.dist);
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o.mat = nearestMat(a, b);
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return o;
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}
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SurfacePoint qIntersect(SurfacePoint a, SurfacePoint b, float smooth) {
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SurfacePoint o;
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o.dist = smax(a.dist, b.dist, smooth);
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o.mat = mixMat(a, b);
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return o;
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}
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// --------------------------------
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// single sdf operations
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// --------------------------------
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float qRound(float a, float radius) {
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return a - radius;
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}
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SurfacePoint qRound(SurfacePoint a, float radius) {
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a.dist -= radius;
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return a;
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}
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// --------------------------------
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// spatial warping
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// --------------------------------
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float3 rotX(float3 p, float a) {
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return mul(float3x3(1, 0, 0, 0, cos(a), -sin(a), 0, sin(a), cos(a)), p);
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}
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float3 rotY(float3 p, float a) {
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return mul(float3x3(cos(a), 0, sin(a), 0, 1, 0, -sin(a), 0, cos(a)), p);
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}
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float3 rotZ(float3 p, float a) {
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return mul(float3x3(cos(a), -sin(a), 0, sin(a), cos(a), 0, 0, 0, 1), p);
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}
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// repeats space every r units, centered on the origin
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float3 repXYZ(float3 p, float3 r) {
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float3 o = p;
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o = fmod(abs(p + r/2.0), r) - r/2.0;
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o *= sign(o);
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return o;
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}
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// repeats space every r units, centered on the origin, no sign
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float3 repXYZUnsigned(float3 p, float3 r) {
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return fmod(abs(p + r / 2.0), r) - r / 2.0;
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}
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// repeats space
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float3 repXZ(float3 p, float x, float z) {
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float3 o = p;
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o.x = fmod(abs(p.x) + x / 2.0, x) - x / 2.0;
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o.x *= sign(p.x);
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o.z = fmod(abs(p.z) + z / 2.0, z) - z / 2.0;
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o.z *= sign(p.z);
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return o;
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}
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float3 repX(float3 p, float x) {
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float3 o = p;
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o.x = fmod(abs(p.x) + x / 2.0, x) - x / 2.0;
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o.x *= sign(p.x);
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return o;
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}
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