¿Cómo obtener un efecto de sombreado "Brillo" en OpenGL ES 2.0?

Question

Estoy escribiendo una aplicación 3D para iOS. Soy nuevo en OpenGL ES 2.0, así que aún me estoy dedicando a escribir sombreadores básicos. Realmente necesito implementar un efecto "Brillar" en algunos de mis modelos, basado en la textura.

He aquí una muestra:

.

Estoy buscando ejemplos de código para OpenGL ES 2.0. La mayoría del código que encuentro en Internet es para escritorio OpenGL o D3D.

¿Alguna idea?

Answer 1

El sitio web GLSL Sandbox tiene una colección de ejemplos de sombreado. This one has the glow and appears to be able to compile for ES.

Debe ser capaz de modificar estos para sacar uv de su textura.

Aquí es some code directly from this site:

#ifdef GL_ES 
precision mediump float; 
#endif 

#extension GL_OES_standard_derivatives : enable 

uniform float time; 
uniform vec2 mouse; 
uniform vec2 resolution; 

void main(void){ 

    vec2 p = (gl_FragCoord.xy * 2.0 - resolution)/min(resolution.x, resolution.y); 
    vec3 color1 = vec3(0.0, 0.3, 0.5); 
    vec3 color2 = vec3(0.5, 0.0, 0.3); 

    float f = 0.0; 
    float g = 0.0; 
    float h = 0.0; 
    float PI = 3.14159265; 
    for(float i = 0.0; i < 40.0; i++){ 
     if (floor(mouse.x * 41.0) < i) 
      break; 
     float s = sin(time + i * PI/20.0) * 0.8; 
     float c = cos(time + i * PI/20.0) * 0.8; 
     float d = abs(p.x + c); 
     float e = abs(p.y + s); 
     f += 0.001/d; 
     g += 0.001/e; 
     h += 0.00003/(d * e); 
    } 


    gl_FragColor = vec4(f * color1 + g * color2 + vec3(h), 1.0); 
} 

Answer 2

En primer lugar hay un montón de algoritmos y técnicas para generar un efecto de brillo. Solo quiero presentar una posibilidad.

Primero debe crear un material que sea auto-luminoso. Para esto utilizo un modelo de luz blinn-phong modificado, en el cual la dirección a la fuente de luz es siempre la dirección inversa del vector normal del fragmento.

varying vec3 vertPos; 
varying vec3 vertNV; 
varying vec3 vertCol; 

void main() 
{ 
    vec3 color = vertCol; 

    float shininess = 10.0; 
    vec3 normalV = normalize(vertNV); 
    vec3 eyeV = normalize(-vertPos); 
    vec3 halfV = normalize(eyeV + normalV); 
    float NdotH = max(0.0, dot(normalV, halfV)); 
    float glowFac = (shininess + 2.0) * pow(NdotH, shininess)/(2.0 * 3.14159265); 

    gl_FragColor = vec4(color.rgb * (0.5 + glowFac), 1.0); 
} 

En un segundo paso un algoritmo de desenfoque gaussiano se lleva a cabo en la salida. La escena se escribe en el búfer de cuadros con una textura vinculada al plano de color. Un pase de espacio de pantalla utiliza la textura como entrada para difuminar la salida.
Por razones de rendimiento, el algoritmo de desenfoque se realiza primero a lo largo del eje X de la ventana gráfica y en un paso más a lo largo del eje Y de la ventana gráfica.
Puede encontrar una descripción detallada del algoritmo de desenfoque en la respuesta a la pregunta OpenGL es 2.0 Gaussian blur on triangle.

varying vec2 vertPos; 
uniform sampler2D u_textureCol; 
uniform vec2 u_textureSize; 
uniform float u_sigma; 
uniform int u_width; 

float CalcGauss(float x, float sigma) 
{ 
    float coeff = 1.0/(2.0 * 3.14157 * sigma); 
    float expon = -(x*x)/(2.0 * sigma); 
    return (coeff*exp(expon)); 
} 

void main() 
{ 
    vec2 texC = vertPos.st * 0.5 + 0.5; 
    vec4 texCol = texture(u_textureCol, texC); 
    vec4 gaussCol = vec4(texCol.rgb, 1.0); 
    vec2 step = 1.0/u_textureSize; 
    for (int i = 1; i <= u_width; ++ i) 
    { 
     vec2 actStep = vec2(float(i) * step.x, 0.0); // this is for the X-axis 
     // vec2 actStep = vec2(0.0, float(i) * step.y); this would be for the Y-axis 

     float weight = CalcGauss(float(i)/float(u_width), u_sigma); 
     texCol = texture2D(u_textureCol, texC + actStep);  
     gaussCol += vec4(texCol.rgb * weight, weight); 
     texCol = texture2D(u_textureCol, texC - actStep); 
     gaussCol += vec4(texCol.rgb * weight, weight); 
    } 
    gaussCol.rgb /= gaussCol.w; 
    gl_FragColor = vec4(gaussCol.rgb, 1.0); 
} 

Véanse también las respuestas a la siguiente pregunta:

• OpenGL es 2.0 Gaussian blur on triangle
• What kind of blurs can be implemented in pixel shaders?

Véase el siguiente ejemplo de WebGL similar que pone todos juntos:

var readInput = true; 
 
function changeEventHandler(event){ 
 
    readInput = true; 
 
} 
 
    
 
(function loadscene() { 
 
    
 
    var resize, gl, progDraw, progBlurX, progPost, vp_size, blurFB; 
 
    var bufCube = {}; 
 
    var bufQuad = {}; 
 
    var shininess = 10.0; 
 
    var glow = 10.0; 
 
    var sigma = 0.8; 
 
    
 
    function render(delteMS){ 
 

 
     if (readInput) { 
 
      readInput = false; 
 
      var sliderScale = 100; 
 
      shininess = document.getElementById("shine").value; 
 
      glow  = document.getElementById("glow").value/sliderScale; 
 
      sigma  = document.getElementById("sigma").value/sliderScale; 
 
     } 
 

 
     Camera.create(); 
 
     Camera.vp = vp_size; 
 
      
 
     gl.enable(gl.DEPTH_TEST); 
 
     gl.clearColor(0.0, 0.0, 0.0, 1.0); 
 
     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 
 

 
     // set up framebuffer 
 
     gl.bindFramebuffer(gl.FRAMEBUFFER, blurFB[0]); 
 
     gl.viewport(0, 0, blurFB[0].width, blurFB[0].height); 
 
     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 
 
    
 
     // set up draw shader 
 
     ShaderProgram.Use(progDraw.prog); 
 
     ShaderProgram.SetUniformM44(progDraw.prog, "u_projectionMat44", Camera.Perspective()); 
 
     ShaderProgram.SetUniformM44(progDraw.prog, "u_viewMat44", Camera.LookAt()); 
 
     var modelMat = IdentityMat44() 
 
     modelMat = RotateAxis(modelMat, CalcAng(delteMS, 13.0), 0); 
 
     modelMat = RotateAxis(modelMat, CalcAng(delteMS, 17.0), 1); 
 
     ShaderProgram.SetUniformM44(progDraw.prog, "u_modelMat44", modelMat); 
 
     ShaderProgram.SetUniformF1(progDraw.prog, "u_shininess", shininess); 
 
     ShaderProgram.SetUniformF1(progDraw.prog, "u_glow", glow); 
 
     
 
     // draw scene 
 
     VertexBuffer.Draw(bufCube); 
 

 
     // set blur-X framebuffer and bind frambuffer texture 
 
     gl.bindFramebuffer(gl.FRAMEBUFFER, blurFB[1]); 
 
     gl.viewport(0, 0, blurFB[1].width, blurFB[1].height); 
 
     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 
 
     var texUnit = 1; 
 
     gl.activeTexture(gl.TEXTURE0 + texUnit); 
 
     gl.bindTexture(gl.TEXTURE_2D, blurFB[0].color0_texture); 
 

 
     // set up blur-X shader 
 
     ShaderProgram.Use(progBlurX.prog); 
 
     ShaderProgram.SetUniformI1(progBlurX.prog , "u_texture", texUnit) 
 
     ShaderProgram.SetUniformF2(progBlurX.prog , "u_textureSize", vp_size); 
 
     ShaderProgram.SetUniformF1(progBlurX.prog , "u_sigma", sigma) 
 

 
     // draw full screen space 
 
     gl.enableVertexAttribArray(progBlurX.inPos); 
 
     gl.bindBuffer(gl.ARRAY_BUFFER, bufQuad.pos); 
 
     gl.vertexAttribPointer(progBlurX.inPos, 2, gl.FLOAT, false, 0, 0); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, bufQuad.inx); 
 
     gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0); 
 
     gl.disableVertexAttribArray(progBlurX.inPos); 
 

 
     // reset framebuffer and bind frambuffer texture 
 
     gl.bindFramebuffer(gl.FRAMEBUFFER, null); 
 
     gl.viewport(0, 0, vp_size[0], vp_size[1]); 
 
     gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT); 
 
     texUnit = 2; 
 
     gl.activeTexture(gl.TEXTURE0 + texUnit); 
 
     gl.bindTexture(gl.TEXTURE_2D, blurFB[1].color0_texture); 
 

 
     // set up pst process shader 
 
     ShaderProgram.Use(progPost.prog); 
 
     ShaderProgram.SetUniformI1(progPost.prog, "u_texture", texUnit) 
 
     ShaderProgram.SetUniformF2(progPost.prog, "u_textureSize", vp_size); 
 
     ShaderProgram.SetUniformF1(progPost.prog, "u_sigma", sigma); 
 

 
     // draw full screen space 
 
     gl.enableVertexAttribArray(progPost.inPos); 
 
     gl.bindBuffer(gl.ARRAY_BUFFER, bufQuad.pos); 
 
     gl.vertexAttribPointer(progPost.inPos, 2, gl.FLOAT, false, 0, 0); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, bufQuad.inx); 
 
     gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_SHORT, 0); 
 
     gl.disableVertexAttribArray(progPost.inPos); 
 

 
     requestAnimationFrame(render); 
 
    } 
 
    
 
    function resize() { 
 
     //vp_size = [gl.drawingBufferWidth, gl.drawingBufferHeight]; 
 
     vp_size = [window.innerWidth, window.innerHeight] 
 
     canvas.width = vp_size[0]; 
 
     canvas.height = vp_size[1]; 
 

 
     var fbsize = Math.max(vp_size[0], vp_size[1])-1; 
 
     fbsize = 1 << 31 - Math.clz32(fbsize); // nearest power of 2 
 
     fbsize = fbsize * 2 
 

 
     blurFB = []; 
 
     for (var i = 0; i < 2; ++ i) { 
 
      fb = gl.createFramebuffer(); 
 
      fb.width = fbsize; 
 
      fb.height = fbsize; 
 
      gl.bindFramebuffer(gl.FRAMEBUFFER, fb); 
 
      fb.color0_texture = gl.createTexture(); 
 
      gl.bindTexture(gl.TEXTURE_2D, fb.color0_texture); 
 
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST); 
 
      gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST); 
 
      gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, fb.width, fb.height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null); 
 
      fb.renderbuffer = gl.createRenderbuffer(); 
 
      gl.bindRenderbuffer(gl.RENDERBUFFER, fb.renderbuffer); 
 
      gl.renderbufferStorage(gl.RENDERBUFFER, gl.DEPTH_COMPONENT16, fb.width, fb.height); 
 
      gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, fb.color0_texture, 0); 
 
      gl.framebufferRenderbuffer(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.RENDERBUFFER, fb.renderbuffer); 
 
      gl.bindTexture(gl.TEXTURE_2D, null); 
 
      gl.bindRenderbuffer(gl.RENDERBUFFER, null); 
 
      gl.bindFramebuffer(gl.FRAMEBUFFER, null); 
 
      blurFB.push(fb); 
 
     } 
 
    } 
 
    
 
    function initScene() { 
 
    
 
     canvas = document.getElementById("canvas"); 
 
     gl = canvas.getContext("experimental-webgl"); 
 
     if (!gl) 
 
     return null; 
 
    
 
     progDraw = {} 
 
     progDraw.prog = ShaderProgram.Create( 
 
     [ { source : "draw-shader-vs", stage : gl.VERTEX_SHADER }, 
 
      { source : "draw-shader-fs", stage : gl.FRAGMENT_SHADER } 
 
     ]); 
 
     if (!progDraw.prog) 
 
      return null; 
 
     progDraw.inPos = gl.getAttribLocation(progDraw.prog, "inPos"); 
 
     progDraw.inNV = gl.getAttribLocation(progDraw.prog, "inNV"); 
 
     progDraw.inCol = gl.getAttribLocation(progDraw.prog, "inCol"); 
 

 
     progBlurX = {} 
 
     progBlurX.prog = ShaderProgram.Create( 
 
     [ { source : "post-shader-vs", stage : gl.VERTEX_SHADER }, 
 
      { source : "blurX-shader-fs", stage : gl.FRAGMENT_SHADER } 
 
     ]); 
 
     progBlurX.inPos = gl.getAttribLocation(progBlurX.prog, "inPos"); 
 
     if (!progBlurX.prog) 
 
      return;  
 

 
     progPost = {} 
 
     progPost.prog = ShaderProgram.Create( 
 
     [ { source : "post-shader-vs", stage : gl.VERTEX_SHADER }, 
 
      { source : "blurY-shader-fs", stage : gl.FRAGMENT_SHADER } 
 
     ]); 
 
     progPost.inPos = gl.getAttribLocation(progPost.prog, "inPos"); 
 
     if (!progPost.prog) 
 
      return; 
 
     
 
     // create cube 
 
     var cubePos = [ 
 
     -1.0, -1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 1.0, 1.0, -1.0, 1.0, 1.0, 
 
     -1.0, -1.0, -1.0, 1.0, -1.0, -1.0, 1.0, 1.0, -1.0, -1.0, 1.0, -1.0 ]; 
 
     var cubeCol = [ 1.0, 0.0, 0.0, 1.0, 0.5, 0.0, 1.0, 0.0, 1.0, 1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0 ]; 
 
     var cubeHlpInx = [ 0, 1, 2, 3, 1, 5, 6, 2, 5, 4, 7, 6, 4, 0, 3, 7, 3, 2, 6, 7, 1, 0, 4, 5 ]; 
 
     var cubePosData = []; 
 
     for (var i = 0; i < cubeHlpInx.length; ++ i) { 
 
     cubePosData.push(cubePos[cubeHlpInx[i]*3], cubePos[cubeHlpInx[i]*3+1], cubePos[cubeHlpInx[i]*3+2]); 
 
     } 
 
     var cubeNVData = []; 
 
     for (var i1 = 0; i1 < cubeHlpInx.length; i1 += 4) { 
 
     var nv = [0, 0, 0]; 
 
     for (i2 = 0; i2 < 4; ++ i2) { 
 
      var i = i1 + i2; 
 
      nv[0] += cubePosData[i*3]; nv[1] += cubePosData[i*3+1]; nv[2] += cubePosData[i*3+2]; 
 
     } 
 
     for (i2 = 0; i2 < 4; ++ i2) 
 
     cubeNVData.push(nv[0], nv[1], nv[2]); 
 
     } 
 
     var cubeColData = []; 
 
     for (var is = 0; is < 6; ++ is) { 
 
     for (var ip = 0; ip < 4; ++ ip) { 
 
     cubeColData.push(cubeCol[is*3], cubeCol[is*3+1], cubeCol[is*3+2]); 
 
     } 
 
     } 
 
     var cubeInxData = []; 
 
     for (var i = 0; i < cubeHlpInx.length; i += 4) { 
 
     cubeInxData.push(i, i+1, i+2, i, i+2, i+3); 
 
     } 
 
     bufCube = VertexBuffer.Create(
 
     [ { data : cubePosData, attrSize : 3, attrLoc : progDraw.inPos }, 
 
     { data : cubeNVData, attrSize : 3, attrLoc : progDraw.inNV }, 
 
     { data : cubeColData, attrSize : 3, attrLoc : progDraw.inCol } ], 
 
     cubeInxData); 
 

 
     bufQuad.pos = gl.createBuffer(); 
 
     gl.bindBuffer(gl.ARRAY_BUFFER, bufQuad.pos); 
 
     gl.bufferData(gl.ARRAY_BUFFER, new Float32Array([ -1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0 ]), gl.STATIC_DRAW); 
 
     bufQuad.inx = gl.createBuffer(); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, bufQuad.inx); 
 
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array([ 0, 1, 2, 0, 2, 3 ]), gl.STATIC_DRAW); 
 
     
 
     window.onresize = resize; 
 
     resize(); 
 
     requestAnimationFrame(render); 
 
    } 
 
    
 
    function Fract(val) { 
 
     return val - Math.trunc(val); 
 
    } 
 
    function CalcAng(deltaTime, intervall) { 
 
     return Fract(deltaTime/(1000*intervall)) * 2.0 * Math.PI; 
 
    } 
 
    function CalcMove(deltaTime, intervall, range) { 
 
     var pos = self.Fract(deltaTime/(1000*intervall)) * 2.0 
 
     var pos = pos < 1.0 ? pos : (2.0-pos) 
 
     return range[0] + (range[1] - range[0]) * pos; 
 
    }  
 
    function EllipticalPosition(a, b, angRag) { 
 
     var a_b = a * a - b * b 
 
     var ea = (a_b <= 0) ? 0 : Math.sqrt(a_b); 
 
     var eb = (a_b >= 0) ? 0 : Math.sqrt(-a_b); 
 
     return [ a * Math.sin(angRag) - ea, b * Math.cos(angRag) - eb, 0 ]; 
 
    } 
 
    
 
    glArrayType = typeof Float32Array !="undefined" ? Float32Array : (typeof WebGLFloatArray != "undefined" ? WebGLFloatArray : Array); 
 
    
 
    function IdentityMat44() { 
 
    var m = new glArrayType(16); 
 
    m[0] = 1; m[1] = 0; m[2] = 0; m[3] = 0; 
 
    m[4] = 0; m[5] = 1; m[6] = 0; m[7] = 0; 
 
    m[8] = 0; m[9] = 0; m[10] = 1; m[11] = 0; 
 
    m[12] = 0; m[13] = 0; m[14] = 0; m[15] = 1; 
 
    return m; 
 
    }; 
 
    
 
    function RotateAxis(matA, angRad, axis) { 
 
     var aMap = [ [1, 2], [2, 0], [0, 1] ]; 
 
     var a0 = aMap[axis][0], a1 = aMap[axis][1]; 
 
     var sinAng = Math.sin(angRad), cosAng = Math.cos(angRad); 
 
     var matB = new glArrayType(16); 
 
     for (var i = 0; i < 16; ++ i) matB[i] = matA[i]; 
 
     for (var i = 0; i < 3; ++ i) { 
 
      matB[a0*4+i] = matA[a0*4+i] * cosAng + matA[a1*4+i] * sinAng; 
 
      matB[a1*4+i] = matA[a0*4+i] * -sinAng + matA[a1*4+i] * cosAng; 
 
     } 
 
     return matB; 
 
    } 
 
    
 
    function Cross(a, b) { return [ a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0], 0.0 ]; } 
 
    function Dot(a, b) { return a[0]*b[0] + a[1]*b[1] + a[2]*b[2]; } 
 
    function Normalize(v) { 
 
     var len = Math.sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); 
 
     return [ v[0]/len, v[1]/len, v[2]/len ]; 
 
    } 
 
    
 
    var Camera = {}; 
 
    Camera.create = function() { 
 
     this.pos = [0, 3, 0.0]; 
 
     this.target = [0, 0, 0]; 
 
     this.up  = [0, 0, 1]; 
 
     this.fov_y = 90; 
 
     this.vp  = [800, 600]; 
 
     this.near = 0.5; 
 
     this.far = 100.0; 
 
    } 
 
    Camera.Perspective = function() { 
 
     var fn = this.far + this.near; 
 
     var f_n = this.far - this.near; 
 
     var r = this.vp[0]/this.vp[1]; 
 
     var t = 1/Math.tan(Math.PI * this.fov_y/360); 
 
     var m = IdentityMat44(); 
 
     m[0] = t/r; m[1] = 0; m[2] = 0;        m[3] = 0; 
 
     m[4] = 0; m[5] = t; m[6] = 0;        m[7] = 0; 
 
     m[8] = 0; m[9] = 0; m[10] = -fn/f_n;      m[11] = -1; 
 
     m[12] = 0; m[13] = 0; m[14] = -2 * this.far * this.near/f_n; m[15] = 0; 
 
     return m; 
 
    } 
 
    Camera.LookAt = function() { 
 
     var mz = Normalize([ this.pos[0]-this.target[0], this.pos[1]-this.target[1], this.pos[2]-this.target[2] ]); 
 
     var mx = Normalize(Cross(this.up, mz)); 
 
     var my = Normalize(Cross(mz, mx)); 
 
     var tx = Dot(mx, this.pos); 
 
     var ty = Dot(my, this.pos); 
 
     var tz = Dot([-mz[0], -mz[1], -mz[2]], this.pos); 
 
     var m = IdentityMat44(); 
 
     m[0] = mx[0]; m[1] = my[0]; m[2] = mz[0]; m[3] = 0; 
 
     m[4] = mx[1]; m[5] = my[1]; m[6] = mz[1]; m[7] = 0; 
 
     m[8] = mx[2]; m[9] = my[2]; m[10] = mz[2]; m[11] = 0; 
 
     m[12] = tx; m[13] = ty; m[14] = tz; m[15] = 1; 
 
     return m; 
 
    } 
 
    
 
    var ShaderProgram = {}; 
 
    ShaderProgram.Create = function(shaderList) { 
 
     var shaderObjs = []; 
 
     for (var i_sh = 0; i_sh < shaderList.length; ++ i_sh) { 
 
      var shderObj = this.CompileShader(shaderList[i_sh].source, shaderList[i_sh].stage); 
 
      if (shderObj == 0) 
 
       return 0; 
 
      shaderObjs.push(shderObj); 
 
     } 
 
     var progObj = this.LinkProgram(shaderObjs) 
 
     if (progObj != 0) { 
 
      progObj.attribIndex = {}; 
 
      var noOfAttributes = gl.getProgramParameter(progObj, gl.ACTIVE_ATTRIBUTES); 
 
      for (var i_n = 0; i_n < noOfAttributes; ++ i_n) { 
 
       var name = gl.getActiveAttrib(progObj, i_n).name; 
 
       progObj.attribIndex[name] = gl.getAttribLocation(progObj, name); 
 
      } 
 
      progObj.unifomLocation = {}; 
 
      var noOfUniforms = gl.getProgramParameter(progObj, gl.ACTIVE_UNIFORMS); 
 
      for (var i_n = 0; i_n < noOfUniforms; ++ i_n) { 
 
       var name = gl.getActiveUniform(progObj, i_n).name; 
 
       progObj.unifomLocation[name] = gl.getUniformLocation(progObj, name); 
 
      } 
 
     } 
 
     return progObj; 
 
    } 
 
    ShaderProgram.AttributeIndex = function(progObj, name) { return progObj.attribIndex[name]; } 
 
    ShaderProgram.UniformLocation = function(progObj, name) { return progObj.unifomLocation[name]; } 
 
    ShaderProgram.Use = function(progObj) { gl.useProgram(progObj); } 
 
    ShaderProgram.SetUniformI1 = function(progObj, name, val) { if(progObj.unifomLocation[name]) gl.uniform1i(progObj.unifomLocation[name], val); } 
 
    ShaderProgram.SetUniformF1 = function(progObj, name, val) { if(progObj.unifomLocation[name]) gl.uniform1f(progObj.unifomLocation[name], val); } 
 
    ShaderProgram.SetUniformF2 = function(progObj, name, arr) { if(progObj.unifomLocation[name]) gl.uniform2fv(progObj.unifomLocation[name], arr); } 
 
    ShaderProgram.SetUniformF3 = function(progObj, name, arr) { if(progObj.unifomLocation[name]) gl.uniform3fv(progObj.unifomLocation[name], arr); } 
 
    ShaderProgram.SetUniformF4 = function(progObj, name, arr) { if(progObj.unifomLocation[name]) gl.uniform4fv(progObj.unifomLocation[name], arr); } 
 
    ShaderProgram.SetUniformM33 = function(progObj, name, mat) { if(progObj.unifomLocation[name]) gl.uniformMatrix3fv(progObj.unifomLocation[name], false, mat); } 
 
    ShaderProgram.SetUniformM44 = function(progObj, name, mat) { if(progObj.unifomLocation[name]) gl.uniformMatrix4fv(progObj.unifomLocation[name], false, mat); } 
 
    ShaderProgram.CompileShader = function(source, shaderStage) { 
 
     var shaderScript = document.getElementById(source); 
 
     if (shaderScript) 
 
     source = shaderScript.text; 
 
     var shaderObj = gl.createShader(shaderStage); 
 
     gl.shaderSource(shaderObj, source); 
 
     gl.compileShader(shaderObj); 
 
     var status = gl.getShaderParameter(shaderObj, gl.COMPILE_STATUS); 
 
     if (!status) alert(gl.getShaderInfoLog(shaderObj)); 
 
     return status ? shaderObj : null; 
 
    } 
 
    ShaderProgram.LinkProgram = function(shaderObjs) { 
 
     var prog = gl.createProgram(); 
 
     for (var i_sh = 0; i_sh < shaderObjs.length; ++ i_sh) 
 
      gl.attachShader(prog, shaderObjs[i_sh]); 
 
     gl.linkProgram(prog); 
 
     status = gl.getProgramParameter(prog, gl.LINK_STATUS); 
 
     if (!status) alert("Could not initialise shaders"); 
 
     gl.useProgram(null); 
 
     return status ? prog : null; 
 
    } 
 
    
 
    var VertexBuffer = {}; 
 
    VertexBuffer.Create = function(attributes, indices) { 
 
     var buffer = {}; 
 
     buffer.buf = []; 
 
     buffer.attr = [] 
 
     for (var i = 0; i < attributes.length; ++ i) { 
 
      buffer.buf.push(gl.createBuffer()); 
 
      buffer.attr.push({ size : attributes[i].attrSize, loc : attributes[i].attrLoc }); 
 
      gl.bindBuffer(gl.ARRAY_BUFFER, buffer.buf[i]); 
 
      gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(attributes[i].data), gl.STATIC_DRAW); 
 
     } 
 
     buffer.inx = gl.createBuffer(); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, buffer.inx); 
 
     gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(indices), gl.STATIC_DRAW); 
 
     buffer.inxLen = indices.length; 
 
     gl.bindBuffer(gl.ARRAY_BUFFER, null); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null); 
 
     return buffer; 
 
    } 
 
    VertexBuffer.Draw = function(bufObj) { 
 
    for (var i = 0; i < bufObj.buf.length; ++ i) { 
 
      gl.bindBuffer(gl.ARRAY_BUFFER, bufObj.buf[i]); 
 
      gl.vertexAttribPointer(bufObj.attr[i].loc, bufObj.attr[i].size, gl.FLOAT, false, 0, 0); 
 
      gl.enableVertexAttribArray(bufObj.attr[i].loc); 
 
     } 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, bufObj.inx); 
 
     gl.drawElements(gl.TRIANGLES, bufObj.inxLen, gl.UNSIGNED_SHORT, 0); 
 
     for (var i = 0; i < bufObj.buf.length; ++ i) 
 
     gl.disableVertexAttribArray(bufObj.attr[i].loc); 
 
     gl.bindBuffer(gl.ARRAY_BUFFER, null); 
 
     gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null); 
 
    } 
 
    
 
    initScene(); 
 
    
 
})();

html,body { 
 
    height: 100%; 
 
    width: 100%; 
 
    margin: 0; 
 
    overflow: hidden; 
 
} 
 

 
#gui { 
 
    position : absolute; 
 
    top : 0; 
 
    left : 0; 
 
}

<script id="draw-shader-vs" type="x-shader/x-vertex"> 
 
    precision highp float; 
 
    
 
    attribute vec3 inPos; 
 
    attribute vec3 inNV; 
 
    attribute vec3 inCol; 
 
    
 
    varying vec3 vertPos; 
 
    varying vec3 vertNV; 
 
    varying vec3 vertCol; 
 
    
 
    uniform mat4 u_projectionMat44; 
 
    uniform mat4 u_viewMat44; 
 
    uniform mat4 u_modelMat44; 
 
    
 
    void main() 
 
    { 
 
     mat4 mv  = u_viewMat44 * u_modelMat44; 
 
     vertCol  = inCol; 
 
     vertNV  = normalize(mat3(mv) * inNV); 
 
     vec4 viewPos = mv * vec4(inPos, 1.0); 
 
     vertPos  = viewPos.xyz; 
 
     gl_Position = u_projectionMat44 * viewPos; 
 
    } 
 
</script> 
 
    
 
<script id="draw-shader-fs" type="x-shader/x-fragment"> 
 
    precision mediump float; 
 

 
    varying vec3 vertPos; 
 
    varying vec3 vertNV; 
 
    varying vec3 vertCol; 
 
    
 
    uniform float u_shininess; 
 
    uniform float u_glow; 
 
    
 
    void main() 
 
    { 
 
     vec3 color = vertCol; 
 
     vec3 normalV = normalize(vertNV); 
 
     vec3 eyeV  = normalize(-vertPos); 
 
     vec3 halfV = normalize(eyeV + normalV); 
 
     float NdotH = max(0.0, dot(normalV, halfV)); 
 
     float shineFac = (u_shininess + 2.0) * pow(NdotH, u_shininess)/(2.0 * 3.14159265); 
 
     gl_FragColor = vec4(color.rgb * u_glow * shineFac * 0.5, 1.0); 
 
    } 
 
</script> 
 
    
 
<script id="post-shader-vs" type="x-shader/x-vertex"> 
 
    precision mediump float; 
 
    
 
    attribute vec2 inPos; 
 
    
 
    varying vec2 pos; 
 
    
 
    void main() 
 
    { 
 
     pos = inPos; 
 
     gl_Position = vec4(inPos, 0.0, 1.0); 
 
    } 
 
</script> 
 
    
 
<script id="blurX-shader-fs" type="x-shader/x-fragment"> 
 
    precision mediump float; 
 
    
 
    varying vec2 pos; 
 
    
 
    uniform sampler2D u_texture; 
 
    uniform vec2  u_textureSize; 
 
    uniform float  u_sigma; 
 
    
 
    float CalcGauss(float x, float sigma) 
 
    { 
 
     float coeff = 1.0/(2.0 * 3.14157 * sigma); 
 
     float expon = -(x*x)/(2.0 * sigma); 
 
     return (coeff*exp(expon)); 
 
    } 
 
    
 
    void main() 
 
    { 
 
     vec2 texC = pos.st * 0.5 + 0.5; 
 
     vec4 texCol = texture2D(u_texture, texC); 
 
     vec4 gaussCol = vec4(texCol.rgb, 1.0); 
 
     float stepX = 1.0/u_textureSize.x; 
 
     for (int i = 1; i <= 20; ++ i) 
 
     { 
 
      float weight = CalcGauss(float(i)/32.0, u_sigma * 0.5); 
 
      texCol = texture2D(u_texture, texC + vec2(float(i) * stepX, 0.0)); 
 
      gaussCol += vec4(texCol.rgb * weight, weight); 
 
      texCol = texture2D(u_texture, texC - vec2(float(i) * stepX, 0.0)); 
 
      gaussCol += vec4(texCol.rgb * weight, weight); 
 
     } 
 
     gaussCol.rgb /= gaussCol.w; 
 
     gl_FragColor = vec4(gaussCol.rgb, 1.0); 
 
    } 
 
</script> 
 
    
 
<script id="blurY-shader-fs" type="x-shader/x-fragment"> 
 
    precision mediump float; 
 
    
 
    varying vec2 pos; 
 
    
 
    uniform sampler2D u_texture; 
 
    uniform vec2  u_textureSize; 
 
    uniform float  u_sigma; 
 
    
 
    float CalcGauss(float x, float sigma) 
 
    { 
 
     float coeff = 1.0/(2.0 * 3.14157 * sigma); 
 
     float expon = -(x*x)/(2.0 * sigma); 
 
     return (coeff*exp(expon)); 
 
    } 
 
    
 
    void main() 
 
    { 
 
     vec2 texC = pos.st * 0.5 + 0.5; 
 
     vec4 texCol = texture2D(u_texture, texC); 
 
     vec4 gaussCol = vec4(texCol.rgb, 1.0); 
 
     float stepY = 1.0/u_textureSize.y; 
 
     for (int i = 1; i <= 20; ++ i) 
 
     { 
 
      float weight = CalcGauss(float(i)/32.0, u_sigma * 0.5); 
 
      texCol = texture2D(u_texture, texC + vec2(0.0, float(i) * stepY)); 
 
      gaussCol += vec4(texCol.rgb * weight, weight); 
 
      texCol = texture2D(u_texture, texC - vec2(0.0, float(i) * stepY)); 
 
      gaussCol += vec4(texCol.rgb * weight, weight); 
 
     } 
 
     vec3 hdrCol = 2.0 * gaussCol.xyz/gaussCol.w; 
 
     vec3 mappedCol = vec3(1.0) - exp(-hdrCol.rgb * 3.0); 
 
     gl_FragColor = vec4(clamp(mappedCol.rgb, 0.0, 1.0), 1.0); 
 
    } 
 
</script> 
 

 
<div> 
 
    <form id="gui" name="inputs"> 
 
     <table> 
 
      <tr> <td> <font color= #CCF>shininess</font> </td> 
 
       <td> <input type="range" id="shine" min="0" max="50" value="10" onchange="changeEventHandler(event);"/></td> </tr> 
 
      <tr> <td> <font color= #CCF>glow</font> </td> 
 
       <td> <input type="range" id="glow" min="100" max="400" value="300" onchange="changeEventHandler(event);"/></td> </tr> 
 
      <tr> <td> <font color= #CCF>blur</font> </td> 
 
       <td> <input type="range" id="sigma" min="1" max="100" value="60" onchange="changeEventHandler(event);"/></td> </tr> 
 
     </table> 
 
    </form> 
 
</div> 
 

 
<canvas id="canvas" style="border: none;" width="100%" height="100%"></canvas>