split up the default files into (quite a few) small parts

e.g. the primitives from different sources (iq, cupe) have their own
includes now, as does the sphere tracer and the camera from iq's
"raymarching primitives" on shadertoy.

glsl/defaultFiles.js

@@ -5,25 +5,26 @@ files.builtin = {
void main() {
  gl_FragColor = vec4(gl_FragCoord.xy / iResolution, blue, 1.0);
}`,
  "default.frag": `const int MaximumRaySteps = 150;
const float MinimumDistance = 0.0001;
  "default.frag": `//#include "includes/sphere-tracer.frag"
//#include "includes/iq-primitives.frag"
//#include "includes/cupe-primitives.frag"
float DistanceEstimator(vec3 pos);
uniform vec3 offset; //#slider[(0.0,10.0,20.0),(0.0,10.0,20.0),(0.0,2.5,20.0)]
float trace(vec3 from, vec3 direction) {
	float totalDistance = 0.0;
  int stepsDone = 0;
	for (int steps = 0; steps < MaximumRaySteps; steps++) {
		vec3 p = from + totalDistance * direction;
		float distance = DistanceEstimator(p);
		totalDistance += distance;
    stepsDone = steps;
		if (distance < MinimumDistance) break;
	}
	return 1.0-float(stepsDone)/float(MaximumRaySteps);
float DistanceEstimator(vec3 pos) {
  pMod1(pos.x, offset.x);
  pMod1(pos.y, offset.y);
  pMod1(pos.z, offset.z + sin(iGlobalTime));
  //return sphere(pos);
  //return min(sphere(vec3(pos.x, pos.y - 0.5, pos.z), 0.75),
  //           udBox(pos, vec3(1.0, 0.3, 1.0)));
  return min(max(-sphere(pos), udBox(pos, vec3(0.75))),
             sphere(pos, 0.05 + 0.25 * (1.0 + sin(iGlobalTime * 0.5)*0.5)));
}
float sphere(vec3 pos) {
//#include "includes/default-main.frag"
`,
  "includes/iq-primitives.frag": `float sphere(vec3 pos) {
  return length(pos) - 1.0;
}
@@ -34,28 +35,31 @@ float sphere(vec3 pos, float size) {
float udBox( vec3 p, vec3 b ) {
  return length(max(abs(p)-b,0.0));
}
float pMod1(inout float p, float size) {
`,
  "includes/cupe-primitives.frag": `float pMod1(inout float p, float size) {
  float halfsize = size * 0.5;
  float c = floor((p + halfsize)/size);
  p = mod(p+halfsize, size)-halfsize;
  return c;
}
uniform vec3 offset; //#slider[(0.0,10.0,20.0),(0.0,10.0,20.0),(0.0,2.5,20.0)]
}`,
  "includes/sphere-tracer.frag": `const int MaximumRaySteps = 150;
const float MinimumDistance = 0.0001;
float DistanceEstimator(vec3 pos) {
  pMod1(pos.x, offset.x);
  pMod1(pos.y, offset.y);
  pMod1(pos.z, offset.z + sin(iGlobalTime));
  //return sphere(pos);
  //return min(sphere(vec3(pos.x, pos.y - 0.5, pos.z), 0.75),
  //           udBox(pos, vec3(1.0, 0.3, 1.0)));
  return min(max(-sphere(pos), udBox(pos, vec3(0.75))),
             sphere(pos, 0.05 + 0.25 * (1.0 + sin(iGlobalTime * 0.5)*0.5)));
}
float DistanceEstimator(vec3 pos);
mat3 setCamera( in vec3 ro, in vec3 ta, float cr ) {
float trace(vec3 from, vec3 direction) {
	float totalDistance = 0.0;
  int stepsDone = 0;
	for (int steps = 0; steps < MaximumRaySteps; steps++) {
		vec3 p = from + totalDistance * direction;
		float distance = DistanceEstimator(p);
		totalDistance += distance;
    stepsDone = steps;
		if (distance < MinimumDistance) break;
	}
	return 1.0-float(stepsDone)/float(MaximumRaySteps);
}`,
  "includes/default-main.frag": `mat3 setCamera( in vec3 ro, in vec3 ta, float cr ) {
	vec3 cw = normalize(ta-ro);
	vec3 cp = vec3(sin(cr), cos(cr),0.0);
	vec3 cu = normalize( cross(cw,cp) );