mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-11-14 22:43:53 +01:00
292 lines
8.2 KiB
GLSL
292 lines
8.2 KiB
GLSL
//Inigo Quilez
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//Oh where would I be without you.
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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const int MAX_MARCHING_STEPS = 255;
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const float MIN_DIST = 3.;
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const float MAX_DIST = 6.;
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const float EPSILON = .0001;
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#region ================ Transform ================
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mat3 rotateX(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3(1, 0, 0),
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vec3(0, c, -s),
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vec3(0, s, c)
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);
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}
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mat3 rotateY(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3( c, 0, s),
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vec3( 0, 1, 0),
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vec3(-s, 0, c)
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);
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}
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mat3 rotateZ(float dg) {
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float c = cos(radians(dg));
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float s = sin(radians(dg));
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return mat3(
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vec3(c, -s, 0),
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vec3(s, c, 0),
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vec3(0, 0, 1)
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);
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}
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mat3 inverse(mat3 m) {
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float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];
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float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];
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float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];
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float b01 = a22 * a11 - a12 * a21;
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float b11 = -a22 * a10 + a12 * a20;
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float b21 = a21 * a10 - a11 * a20;
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float det = a00 * b01 + a01 * b11 + a02 * b21;
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return mat3(b01, (-a22 * a01 + a02 * a21), (a12 * a01 - a02 * a11),
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b11, (a22 * a00 - a02 * a20), (-a12 * a00 + a02 * a10),
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b21, (-a21 * a00 + a01 * a20), (a11 * a00 - a01 * a10)) / det;
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}
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#endregion
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#region ================ Primitives ================
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float dot2( in vec2 v ) { return dot(v,v); }
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float dot2( in vec3 v ) { return dot(v,v); }
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float ndot( in vec2 a, in vec2 b ) { return a.x*b.x - a.y*b.y; }
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float sdPlane( vec3 p, vec3 n, float h ) {
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// n must be normalized
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return dot(p,n) + h;
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}
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float sdBox( vec3 p, vec3 b ) {
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vec3 q = abs(p) - b;
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return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0);
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}
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float sdBoxFrame( vec3 p, vec3 b, float e ) {
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p = abs(p)-b;
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vec3 q = abs(p+e)-e;
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return min(min(
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length(max(vec3(p.x,q.y,q.z),0.0))+min(max(p.x,max(q.y,q.z)),0.0),
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length(max(vec3(q.x,p.y,q.z),0.0))+min(max(q.x,max(p.y,q.z)),0.0)),
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length(max(vec3(q.x,q.y,p.z),0.0))+min(max(q.x,max(q.y,p.z)),0.0));
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}
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//////////////////////////////////////////////////////////////////////////////////////////////
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float sdSphere(vec3 p) {
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return length(p) - 1.0;
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}
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float sdEllipsoid( vec3 p, vec3 r ) {
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float k0 = length(p/r);
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float k1 = length(p/(r*r));
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return k0*(k0-1.0)/k1;
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}
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float sdTorus( vec3 p, vec2 t ) {
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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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float sdCutSphere( vec3 p, float r, float h ) {
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// sampling independent computations (only depend on shape)
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float w = sqrt(r*r-h*h);
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// sampling dependant computations
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vec2 q = vec2( length(p.xz), p.y );
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float s = max( (h-r)*q.x*q.x+w*w*(h+r-2.0*q.y), h*q.x-w*q.y );
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return (s<0.0) ? length(q)-r :
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(q.x<w) ? h - q.y :
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length(q-vec2(w,h));
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}
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float sdCutHollowSphere( vec3 p, float r, float h, float t ) {
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// sampling independent computations (only depend on shape)
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float w = sqrt(r*r-h*h);
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// sampling dependant computations
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vec2 q = vec2( length(p.xz), p.y );
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return ((h*q.x<w*q.y) ? length(q-vec2(w,h)) :
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abs(length(q)-r) ) - t;
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}
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float sdCappedTorus( vec3 p, vec2 sc, float ra, float rb) {
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p.x = abs(p.x);
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float k = (sc.y*p.x>sc.x*p.y) ? dot(p.xy,sc) : length(p.xy);
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return sqrt( dot(p,p) + ra*ra - 2.0*ra*k ) - rb;
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}
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//////////////////////////////////////////////////////////////////////////////////////////////
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float sdCylinder( vec3 p, vec3 c ) {
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return length(p.xz-c.xy)-c.z;
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}
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float sdCappedCylinder( vec3 p, float h, float r ) {
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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 sdCapsule( vec3 p, vec3 a, vec3 b, float r ) {
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vec3 pa = p - a, ba = b - a;
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float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1.0 );
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return length( pa - ba*h ) - r;
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}
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float sdCone( vec3 p, vec2 c, float h ) {
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// c is the sin/cos of the angle, h is height
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// Alternatively pass q instead of (c,h),
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// which is the point at the base in 2D
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vec2 q = h*vec2(c.x/c.y,-1.0);
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vec2 w = vec2( length(p.xz), p.y );
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vec2 a = w - q*clamp( dot(w,q)/dot(q,q), 0.0, 1.0 );
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vec2 b = w - q*vec2( clamp( w.x/q.x, 0.0, 1.0 ), 1.0 );
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float k = sign( q.y );
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float d = min(dot( a, a ),dot(b, b));
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float s = max( k*(w.x*q.y-w.y*q.x),k*(w.y-q.y) );
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return sqrt(d)*sign(s);
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}
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float sdCappedCone( vec3 p, float h, float r1, float r2 ) {
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vec2 q = vec2( length(p.xz), p.y );
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vec2 k1 = vec2(r2,h);
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vec2 k2 = vec2(r2-r1,2.0*h);
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vec2 ca = vec2(q.x-min(q.x,(q.y<0.0)?r1:r2), abs(q.y)-h);
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vec2 cb = q - k1 + k2*clamp( dot(k1-q,k2)/dot2(k2), 0.0, 1.0 );
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float s = (cb.x<0.0 && ca.y<0.0) ? -1.0 : 1.0;
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return s*sqrt( min(dot2(ca),dot2(cb)) );
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}
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float sdRoundCone( vec3 p, float r1, float r2, float h ) {
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// sampling independent computations (only depend on shape)
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float b = (r1-r2)/h;
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float a = sqrt(1.0-b*b);
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// sampling dependant computations
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vec2 q = vec2( length(p.xz), p.y );
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float k = dot(q,vec2(-b,a));
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if( k<0.0 ) return length(q) - r1;
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if( k>a*h ) return length(q-vec2(0.0,h)) - r2;
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return dot(q, vec2(a,b) ) - r1;
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}
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float sdSolidAngle( vec3 p, vec2 c, float ra ) {
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// c is the sin/cos of the angle
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vec2 q = vec2( length(p.xz), p.y );
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float l = length(q) - ra;
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float m = length(q - c*clamp(dot(q,c),0.0,ra) );
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return max(l,m*sign(c.y*q.x-c.x*q.y));
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}
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//////////////////////////////////////////////////////////////////////////////////////////////
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float sdOctahedron( vec3 p, float s ) {
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p = abs(p);
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float m = p.x+p.y+p.z-s;
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vec3 q;
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if( 3.0*p.x < m ) q = p.xyz;
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else if( 3.0*p.y < m ) q = p.yzx;
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else if( 3.0*p.z < m ) q = p.zxy;
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else return m*0.57735027;
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float k = clamp(0.5*(q.z-q.y+s),0.0,s);
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return length(vec3(q.x,q.y-s+k,q.z-k));
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}
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float sdPyramid( vec3 p, float h ) {
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float m2 = h*h + 0.25;
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p.xz = abs(p.xz);
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p.xz = (p.z>p.x) ? p.zx : p.xz;
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p.xz -= 0.5;
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vec3 q = vec3( p.z, h*p.y - 0.5*p.x, h*p.x + 0.5*p.y);
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float s = max(-q.x,0.0);
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float t = clamp( (q.y-0.5*p.z)/(m2+0.25), 0.0, 1.0 );
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float a = m2*(q.x+s)*(q.x+s) + q.y*q.y;
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float b = m2*(q.x+0.5*t)*(q.x+0.5*t) + (q.y-m2*t)*(q.y-m2*t);
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float d2 = min(q.y,-q.x*m2-q.y*0.5) > 0.0 ? 0.0 : min(a,b);
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return sqrt( (d2+q.z*q.z)/m2 ) * sign(max(q.z,-p.y));
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}
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#endregion
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float sceneSDF(vec3 p) {
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float d;
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mat3 rx = rotateX(45.);
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mat3 ry = rotateY(45.);
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p = inverse(rx * ry) * p;
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// d = sdSphere(p);
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// d = sdBox(p, vec3(.5));
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d = sdBoxFrame(p, vec3(.5), 0.1);
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return d;
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}
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vec3 normal(vec3 p) {
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return normalize(vec3(
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sceneSDF(vec3(p.x + EPSILON, p.y, p.z)) - sceneSDF(vec3(p.x - EPSILON, p.y, p.z)),
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sceneSDF(vec3(p.x, p.y + EPSILON, p.z)) - sceneSDF(vec3(p.x, p.y - EPSILON, p.z)),
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sceneSDF(vec3(p.x, p.y, p.z + EPSILON)) - sceneSDF(vec3(p.x, p.y, p.z - EPSILON))
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));
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}
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float march(vec3 camera, vec3 direction) {
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float depth = MIN_DIST;
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for (int i = 0; i < MAX_MARCHING_STEPS; i++) {
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float dist = sceneSDF(camera + depth * direction);
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if (dist < EPSILON)
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return depth;
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depth += dist;
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if (depth >= MAX_DIST)
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return MAX_DIST;
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}
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return MAX_DIST;
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}
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void main() {
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float z = 1. / tan(radians(30.) / 2.);
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vec3 dir = normalize(vec3((v_vTexcoord - .5) * 2., -z));
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vec3 eye = vec3(0., 0., 5.);
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float dist = march(eye, dir);
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if(dist > MAX_DIST - EPSILON) {
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gl_FragColor = vec4(0., 0., 0., 1.);
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return;
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}
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vec3 c = vec3(1.);
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float distNorm = 1. - (dist - MIN_DIST) / (MAX_DIST - MIN_DIST);
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distNorm = smoothstep(.0, .3, distNorm) + .2;
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c *= vec3(distNorm);
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vec3 coll = eye + dir * dist;
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vec3 norm = normal(coll);
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vec3 light = normalize(vec3(-0.5, -0.5, 1.));
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float lamo = dot(norm, light) + 0.2;
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c *= lamo;
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gl_FragColor = vec4(c, 1.);
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} |