Merge pull request #12 from davepagurek/feat/renderers

Add shadow and blur render helpers

Author: davepagurek

examples/blur/blur.frag renamed to BlurRenderer.js

@@ -1,3 +1,73 @@
+class BlurRenderer extends Renderer {
+  constructor(target) {
+    super(target)
+    this.focus = (target.height / 2) / tan(PI / 6)
+    this.intensity = 0.05
+    this.numSamples = 15
+  }
+
+  vert() {
+    return BlurRenderer.vert
+  }
+
+  frag() {
+    return BlurRenderer.frag
+  }
+
+  focusHere() {
+    const matrix = new DOMMatrix(this.target._renderer.uMVMatrix.mat4)
+    const center = new DOMPoint(0, 0, 0)
+    const world = center.matrixTransform(matrix)
+    this.focus = -world.z
+  }
+
+  setIntensity(intensity) {
+    this.intensity = intensity
+  }
+
+  setSamples(numSamples) {
+    this.numSamples = numSamples
+  }
+
+  getUniforms() {
+    return {
+      uImg: this.fbo.color,
+      uDepth: this.fbo.depth,
+      uSize: [this.target.width, this.target.height],
+      uIntensity: this.intensity,
+      uNumSamples: this.numSamples,
+      uNear: this.target._renderer._curCamera._near,
+      uFar: this.target._renderer._curCamera._far,
+      uTargetZ: this.focus,
+    }
+  }
+}
+
+p5.prototype.createBlurRenderer = function() {
+  return new BlurRenderer(this)
+}
+
+BlurRenderer.vert = `
+precision highp float;
+
+attribute vec3 aPosition;
+attribute vec3 aNormal;
+attribute vec2 aTexCoord;
+
+uniform mat4 uModelViewMatrix;
+uniform mat4 uProjectionMatrix;
+uniform mat3 uNormalMatrix;
+
+varying highp vec2 vVertTexCoord;
+
+void main(void) {
+  vec4 positionVec4 = vec4(aPosition, 1.0);
+  gl_Position = uProjectionMatrix * uModelViewMatrix * positionVec4;
+  vVertTexCoord = aTexCoord;
+}
+`
+
+BlurRenderer.frag = `
 precision highp float;
 varying highp vec2 vVertTexCoord;
 
@@ -52,3 +122,4 @@ void main() {
   color /= total;
   gl_FragColor = color;
 }
+`

ContactShadowRenderer.js

@@ -0,0 +1,201 @@
+class ContactShadowRenderer extends Renderer {
+  constructor(target) {
+    super(target)
+    this.target._renderer.GL.getExtension('OES_standard_derivatives')
+    this.intensity = 0.5
+    this.numSamples = 15
+    this.exponent = 250
+    this.bias = 1.
+    this.searchRadius = 100
+  }
+
+  vert() {
+    return ContactShadowRenderer.vert
+  }
+
+  frag() {
+    return ContactShadowRenderer.frag
+  }
+
+  setIntensity(intensity) {
+    this.intensity = intensity
+  }
+  setSamples(numSamples) {
+    this.numSamples = numSamples
+  }
+  setExponent(exponent) {
+    this.exponent = exponent
+  }
+  setBias(bias) {
+    this.bias = bias
+  }
+  setSearchRadius(radius) {
+    this.searchRadius = radius
+  }
+
+  getUniforms() {
+    const projInfo = [
+      -2 / (this.target.width * this.target._renderer.uPMatrix.mat4[0]),
+      -2 / (this.target.height * this.target._renderer.uPMatrix.mat4[5]),
+      (1 - this.target._renderer.uPMatrix.mat4[2]) / this.target._renderer.uPMatrix.mat4[0],
+      (1 + this.target._renderer.uPMatrix.mat4[6]) / this.target._renderer.uPMatrix.mat4[5]
+    ]
+
+    return {
+      uImg: this.fbo.color,
+      uDepth: this.fbo.depth,
+      uSize: [this.target.width, this.target.height],
+      uIntensity: this.intensity,
+      uNumSamples: this.numSamples,
+      uNear: this.target._renderer._curCamera.cameraNear,
+      uFar: this.target._renderer._curCamera.cameraFar,
+      uProjInfo: projInfo,
+      uExponent: this.exponent,
+      uBias: this.bias,
+      uSearchRadius: this.searchRadius,
+    }
+  }
+}
+
+p5.prototype.createContactShadowRenderer = function() {
+  return new ContactShadowRenderer(this)
+}
+
+ContactShadowRenderer.vert = `
+attribute vec3 aPosition;
+attribute vec3 aNormal;
+attribute vec2 aTexCoord;
+
+uniform mat4 uModelViewMatrix;
+uniform mat4 uProjectionMatrix;
+uniform mat3 uNormalMatrix;
+
+varying highp vec2 vVertTexCoord;
+
+void main(void) {
+  vec4 positionVec4 = vec4(aPosition, 1.0);
+  gl_Position = uProjectionMatrix * uModelViewMatrix * positionVec4;
+  vVertTexCoord = aTexCoord;
+}
+`
+
+ContactShadowRenderer.frag = `
+#extension GL_OES_standard_derivatives : enable
+precision highp float;
+varying highp vec2 vVertTexCoord;
+
+uniform sampler2D uImg;
+uniform sampler2D uDepth;
+uniform vec2 uSize;
+uniform int uNumSamples;
+uniform float uNear;
+uniform float uFar;
+uniform vec4 uProjInfo;
+uniform float uSearchRadius;
+uniform float uIntensity;
+uniform float uExponent;
+uniform float uBias;
+
+const int MAX_NUM_SAMPLES = 50;
+
+float rand(vec2 co){
+  return fract(sin(dot(co.xy, vec2(12.9898,78.233))) * 43758.5453);
+}
+
+vec3 worldFromScreen(vec2 offset) {
+  float z = uNear * uFar  / ((uNear - uFar) * texture2D(uDepth, vVertTexCoord + offset).x + uFar);
+  return vec3((((vVertTexCoord + offset) * uSize) * uProjInfo.xy + uProjInfo.zw) * z, z);
+}
+
+vec2 screenFromWorld(vec3 world) {
+  return (world.xy/world.z - uProjInfo.zw)/uProjInfo.xy;
+}
+
+const float EPSILON = 0.01;
+
+mat4 axisAngleRotation(vec3 axis, float angle) {
+  axis = normalize(axis);
+  float s = sin(angle);
+  float c = cos(angle);
+  float oc = 1.0 - c;
+
+  return mat4(oc * axis.x * axis.x + c,           oc * axis.x * axis.y - axis.z * s,  oc * axis.z * axis.x + axis.y * s,  0.0,
+              oc * axis.x * axis.y + axis.z * s,  oc * axis.y * axis.y + c,           oc * axis.y * axis.z - axis.x * s,  0.0,
+              oc * axis.z * axis.x - axis.y * s,  oc * axis.y * axis.z + axis.x * s,  oc * axis.z * axis.z + c,           0.0,
+              0.0,                                0.0,                                0.0,                                1.0);
+}
+vec3 adjustNormal(
+  vec3 origNormal,
+  vec3 displacementNormal,
+  vec3 noDisplacementNormal
+) {
+  // Find the rotation induced by the displacement
+  float angle = acos(dot(displacementNormal, noDisplacementNormal));
+  vec3 rawAxis = cross(displacementNormal, noDisplacementNormal);
+  if (length(rawAxis) < 0.01) {
+    return origNormal;
+  }
+  vec3 axis = normalize(rawAxis);
+  mat4 rotation = axisAngleRotation(axis, angle);
+
+  // Apply the rotation to the original normal
+  vec3 normal = (rotation * vec4(origNormal, 0.)).xyz;
+  return normal;
+}
+
+void main() {
+  vec4 color = texture2D(uImg, vVertTexCoord);
+  vec3 position = worldFromScreen(vec2(0., 0.));
+  vec3 normal = normalize(cross(dFdx(position), dFdy(position)));
+
+  float radiusSquared = uSearchRadius * uSearchRadius;
+
+  float occlusion = 0.;
+
+  for (int i = 0; i < MAX_NUM_SAMPLES; i++) {
+    if (i >= uNumSamples) break;
+    float t = (float(i + 1) / float(uNumSamples));
+
+    // Sample a sort of random ish coordinate in a half sphere pointing up
+    float phi = t * 11. * ${2 * Math.PI} + 0.5*rand(gl_FragCoord.xy);
+    float theta = t * ${Math.PI / 2} + 0.5*rand(gl_FragCoord.xy);
+    float radius = 1.0 - t*t;
+    vec3 localOff = vec3(
+      radius * cos(phi) * sin(theta),
+      radius * cos(theta),
+      radius * sin(phi) * sin(theta)
+    );
+
+    // Translate that to be a hemisphere oriented with the surface normal
+    vec3 rotatedOff = adjustNormal(localOff, normal, vec3(0., 1., 0.));
+    vec3 testPosition = position + rotatedOff * uSearchRadius;
+    vec2 screenPosition = screenFromWorld(testPosition);
+    vec2 offset = screenPosition / uSize - vVertTexCoord;
+    
+    // At that screen space coordinate, what is the position of the object we see?
+    vec3 samplePos = worldFromScreen(offset);
+
+    // The amount of occlusion is proportional to the *cosine* of the angle between
+    // the line connecting the object to the surface and the surface normal. This is
+    // because light coming in at an angle is more spread out and thus delivers less
+    // energy to the surface.
+    //
+    // The dot product of originToSample and the normal is proportional to this energy
+    // because dot(a, b) is equivalent to length(a)*length(b)*cos(angle_between_a_and_b)
+    vec3 originToSample = samplePos - position;
+    float squaredDistanceToSample = dot(originToSample, originToSample);
+    float vn = dot(originToSample, normal) - uBias;
+
+    // We only let stuff start making a shadow when it's within our search radius. At
+    // the edge it should not occlude, and as it gets closer, it should occlude more.
+    // We'll give it a cubic falloff so it looks smoother.
+    float f = max(radiusSquared - squaredDistanceToSample, 0.0) / radiusSquared;
+    float sampleOcclusion = f * f * f * max(vn / (EPSILON + squaredDistanceToSample), 0.0);
+
+    occlusion += sampleOcclusion;
+  }
+  occlusion = 1.0 - (occlusion / float(uNumSamples));
+  occlusion = clamp(pow(occlusion, 1.0 + uExponent), 0.0, 1.0);
+  gl_FragColor = vec4(color.rgb * mix(1., occlusion, uIntensity), color.a);
+}
+`