高斯，框，径向，方向，运动模糊，变焦模糊等
我读到可以在像素着色器中实现的通道中分解高斯模糊，但找不到任何样本。
是否可以假设任何与自身以外的像素无关的效果都无法在像素着色器中实现？
答案 0 :(得分：4)
只要能够将信息传递给着色器，就可以实现所有内容。
在这种情况下，技巧是执行多次渲染。最终着色器将采用一定数量的采样器，即非模糊源，用于计算模糊值。
例如，使用多个纹理可以根据累积缓冲区模拟效果。
实现高斯模糊，将场景渲染到frambuffer对象上，并在颜色附件上附加纹理。这是第一次通过。
作为第二遍，渲染纹理四边形，其中纹理是在第一步中生成的纹理。纹理坐标从顶点阶段传递到片段阶段，在四边形内插。实际上，每个片段都有纹理坐标;为每个坐标应用偏移量以获取基础坐标周围的文本，并执行高斯模糊。
答案 1 :(得分：3)
后处理效果的一般'管道'
setRenderTarget(myRenderTarget); // or FBO in GL
drawAwsomeScene();
setdefaultRenderTarget(); // draw to screen...
blurShader.use();
// shader needs to know what is the size of one pixel on the screen
blurShader.uniform2f("texelSize", 1/screenW, 1/screenH);
// set the texture with scene rendered...
setRenderTargetTexture();
drawFullScreenQuad();
// other effects...
蓝色的有用示例/教程：http://www.gamerendering.com/2008/10/11/gaussian-blur-filter-shader/
答案 2 :(得分：3)
我实现了一个通用的卷积片段着色器（像素着色器）
#version 120
uniform sampler2D texUnit;
uniform float[9] conMatrix;
uniform float conWeight;
uniform vec2 conPixel;
void main(void)
{
vec4 color = vec4(0.0);
vec2 texCoord = gl_TexCoord[0].st;
vec2 offset = conPixel * 1.5;
vec2 start = texCoord - offset;
vec2 current = start;
for (int i = 0; i < 9; i++)
{
color += texture2D( texUnit, current ) * conMatrix[i];
current.x += conPixel.x;
if (i == 2 || i == 5) {
current.x = start.x;
current.y += conPixel.y;
}
}
gl_FragColor = color * conWeight;
}
模糊：
where conPixel is {1/screen width, 1/screen height}
where conMatrix is {1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0}
where conWeight is 1.0 / 9.0
where texUnit is 0
答案 3 :(得分：0)
经常看到的场景模糊实现是通过后处理实现的高斯模糊。一种可能的实现是具有2遍的高斯模糊着色器
这是一种近似，其在第一遍中沿着X轴首先模糊并且在第二遍中沿着Y轴模糊。这样可以获得更好的模糊效果
模糊着色器使用normal (or Gaussian) distribution。对于2次传球，使用相同的着色器程序，2次传球的单独方向设置，存储在制服vec2 u_dir中。模糊效果的强度可以通过[0.0,1.0]范围内的均匀变量float u_sigma来改变
场景被写入帧缓冲区，其纹理绑定到颜色平面。屏幕空间传递使用纹理作为输入来模糊沿X轴的输出。
X轴模糊传递写入另一个帧缓冲区，纹理绑定到其颜色平面。此纹理用作输入，用于沿Y轴的最终模糊处理
可以在问题OpenGL es 2.0 Gaussian blur on triangle的答案中找到模糊算法的详细说明。
模糊顶点着色器
#version 330
in vec2 inPos;
out vec2 pos;
void main()
{
pos = inPos;
gl_Position = vec4( inPos, 0.0, 1.0 );
}
模糊片段着色器
#version 330
in vec2 pos;
uniform sampler2D u_texture;
uniform vec2 u_textureSize;
uniform float u_sigma;
uniform vec2 u_dir;
float CalcGauss( float x, float sigma )
{
if ( sigma <= 0.0 )
return 0.0;
return exp( -(x*x) / (2.0 * sigma) ) / (2.0 * 3.14157 * sigma);
}
void main()
{
vec2 texC = pos.st * 0.5 + 0.5;
vec4 texCol = texture2D( u_texture, texC );
vec4 gaussCol = vec4( texCol.rgb, 1.0 );
vec2 step = u_dir / u_textureSize;
for ( int i = 1; i <= 32; ++ i )
{
float weight = CalcGauss( float(i) / 32.0, u_sigma * 0.5 );
if ( weight < 1.0/255.0 )
break;
texCol = texture2D( u_texture, texC + step * float(i) );
gaussCol += vec4( texCol.rgb * weight, weight );
texCol = texture2D( u_texture, texC - step * float(i) );
gaussCol += vec4( texCol.rgb * weight, weight );
}
gaussCol.rgb = clamp( gaussCol.rgb / gaussCol.w, 0.0, 1.0 );
gl_FragColor = vec4( gaussCol.rgb, 1.0 );
}
另见以下问题的答案：
查看WebGL示例：
var readInput = true;
function changeEventHandler(event){
readInput = true;
}
(function loadscene() {
var resize, gl, progDraw, progBlur, vp_size, blurFB;
var canvas;
var camera;
var bufCube = {};
var bufQuad = {};
var shininess = 10.0;
var glow = 10.0;
var sigma = 0.8;
var radius = 1.0;
function render(deltaMS){
if ( readInput ) {
//readInput = false;
var sliderScale = 100;
sigma = document.getElementById( "sigma" ).value / sliderScale;
radius = document.getElementById( "radius" ).value / sliderScale;
}
vp_size = [canvas.width, canvas.height];
camera.Update( 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 );
// setup view projection and model
var prjMat = camera.Perspective();
var viewMat = camera.Orbit();
var modelMat = IdentM44();
modelMat = camera.AutoModelMatrix();
// set up draw shader
ShProg.Use( progDraw.prog );
ShProg.SetM44( progDraw.prog, "u_projectionMat44", prjMat );
ShProg.SetM44( progDraw.prog, "u_modelViewMat44", Multiply(viewMat, modelMat) );
ShProg.SetF1( progDraw.prog, "u_shininess", shininess );
// 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
ShProg.Use( progBlur.prog );
ShProg.SetI1( progBlur.prog, "u_texture", texUnit )
ShProg.SetF2( progBlur.prog, "u_textureSize", vp_size );
ShProg.SetF1( progBlur.prog, "u_sigma", sigma )
ShProg.SetF1( progBlur.prog, "u_radius", radius )
ShProg.SetF2( progBlur.prog, "u_dir", [1.0, 0.0] )
// draw full screen space
gl.enableVertexAttribArray( progBlur.inPos );
gl.bindBuffer( gl.ARRAY_BUFFER, bufQuad.pos );
gl.vertexAttribPointer( progBlur.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( progBlur.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
ShProg.SetI1( progBlur.prog, "u_texture", texUnit )
ShProg.SetF1( progBlur.prog, "u_radius", radius )
ShProg.SetF2( progBlur.prog, "u_dir", [0.0, 1.0] )
// draw full screen space
gl.enableVertexAttribArray( progBlur.inPos );
gl.bindBuffer( gl.ARRAY_BUFFER, bufQuad.pos );
gl.vertexAttribPointer( progBlur.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( progBlur.inPos );
requestAnimationFrame(render);
}
function initScene() {
canvas = document.getElementById( "canvas");
gl = canvas.getContext( "experimental-webgl" );
if ( !gl )
return null;
progDraw = {}
progDraw.prog = ShProg.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" );
progBlur = {}
progBlur.prog = ShProg.Create(
[ { source : "post-shader-vs", stage : gl.VERTEX_SHADER },
{ source : "blur-shader-fs", stage : gl.FRAGMENT_SHADER }
] );
progBlur.inPos = gl.getAttribLocation( progBlur.prog, "inPos" );
if ( !progBlur.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 );
camera = new Camera( [0, 3, 0.0], [0, 0, 0], [0, 0, 1], 90, vp_size, 0.5, 100 );
window.onresize = resize;
resize();
requestAnimationFrame(render);
}
function resize() {
//vp_size = [gl.drawingBufferWidth, gl.drawingBufferHeight];
vp_size = [window.innerWidth, window.innerHeight]
//vp_size = [256, 256]
canvas.width = vp_size[0];
canvas.height = vp_size[1];
var fbsize = Math.max(vp_size[0], vp_size[1]);
fbsize = 1 << 31 - Math.clz32(fbsize); // nearest power of 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 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 ];
}
function IdentM44() {
return [ 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 ];
};
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 = matA.slice(0);
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 Rotate(matA, angRad, axis) {
var s = Math.sin(angRad), c = Math.cos(angRad);
var x = axis[0], y = axis[1], z = axis[2];
matB = [
x*x*(1-c)+c, x*y*(1-c)-z*s, x*z*(1-c)+y*s, 0,
y*x*(1-c)+z*s, y*y*(1-c)+c, y*z*(1-c)-x*s, 0,
z*x*(1-c)-y*s, z*y*(1-c)+x*s, z*z*(1-c)+c, 0,
0, 0, 0, 1 ];
return Multiply(matA, matB);
}
function Multiply(matA, matB) {
matC = IdentM44();
for (var i0=0; i0<4; ++i0 )
for (var i1=0; i1<4; ++i1 )
matC[i0*4+i1] = matB[i0*4+0] * matA[0*4+i1] + matB[i0*4+1] * matA[1*4+i1] + matB[i0*4+2] * matA[2*4+i1] + matB[i0*4+3] * matA[3*4+i1]
return matC;
}
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 ];
}
Camera = function( pos, target, up, fov_y, vp, near, far ) {
this.Time = function() { return Date.now(); }
this.pos = pos;
this.target = target;
this.up = up;
this.fov_y = fov_y;
this.vp = vp;
this.near = near;
this.far = far;
this.orbit_mat = this.current_orbit_mat = this.model_mat = this.current_model_mat = IdentM44();
this.mouse_drag = this.auto_spin = false;
this.auto_rotate = true;
this.mouse_start = [0, 0];
this.mouse_drag_axis = [0, 0, 0];
this.mouse_drag_angle = 0;
this.mouse_drag_time = 0;
this.drag_start_T = this.rotate_start_T = this.Time();
this.Ortho = function() {
var fn = this.far + this.near;
var f_n = this.far - this.near;
var w = this.vp[0];
var h = this.vp[1];
return [
2/w, 0, 0, 0,
0, 2/h, 0, 0,
0, 0, -2/f_n, 0,
0, 0, -fn/f_n, 1 ];
};
this.Perspective = function() {
var n = this.near;
var f = this.far;
var fn = f + n;
var f_n = f - n;
var r = this.vp[0] / this.vp[1];
var t = 1 / Math.tan( Math.PI * this.fov_y / 360 );
return [
t/r, 0, 0, 0,
0, t, 0, 0,
0, 0, -fn/f_n, -1,
0, 0, -2*f*n/f_n, 0 ];
};
this.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 );
return [mx[0], my[0], mz[0], 0, mx[1], my[1], mz[1], 0, mx[2], my[2], mz[2], 0, tx, ty, tz, 1];
};
this.Orbit = function() {
return Multiply(this.LookAt(), this.OrbitMatrix());
};
this.OrbitMatrix = function() {
return (this.mouse_drag || (this.auto_rotate && this.auto_spin)) ? Multiply(this.current_orbit_mat, this.orbit_mat) : this.orbit_mat;
};
this.AutoModelMatrix = function() {
return this.auto_rotate ? Multiply(this.current_model_mat, this.model_mat) : this.model_mat;
};
this.Update = function(vp_size) {
if (vp_size)
this.vp = vp_size;
var current_T = this.Time();
this.current_model_mat = IdentM44()
if (this.mouse_drag) {
this.current_orbit_mat = Rotate(IdentM44(), this.mouse_drag_angle, this.mouse_drag_axis);
} else if (this.auto_rotate) {
if (this.auto_spin ) {
if (this.mouse_drag_time > 0 ) {
var angle = this.mouse_drag_angle * (current_T - this.rotate_start_T) / this.mouse_drag_time;
this.current_orbit_mat = Rotate(IdentM44(), angle, this.mouse_drag_axis);
}
} else {
var auto_angle_x = Fract( (current_T - this.rotate_start_T) / 13000.0 ) * 2.0 * Math.PI;
var auto_angle_y = Fract( (current_T - this.rotate_start_T) / 17000.0 ) * 2.0 * Math.PI;
this.current_model_mat = RotateAxis( this.current_model_mat, auto_angle_x, 0 );
this.current_model_mat = RotateAxis( this.current_model_mat, auto_angle_y, 1 );
}
}
};
this.ChangeMotionMode = function(drag, spin, auto ) {
var new_drag = drag;
var new_auto = new_drag ? false : auto;
var new_spin = new_auto ? spin : false;
change = this.mouse_drag != new_drag || this.auto_rotate != new_auto || this.auto_spin != new_spin;
if (!change)
return;
if (new_drag && !this.mouse_drag) {
this.drag_start_T = this.Time();
this.mouse_drag_angle = 0.0;
this.mouse_drag_time = 0;
}
if (new_auto && !this.auto_rotate)
this.rotate_start_T = this.Time();
this.mouse_drag = new_drag;
this.auto_rotate = new_auto;
this.auto_spin = new_spin;
this.orbit_mat = Multiply(this.current_orbit_mat, this.orbit_mat);
this.current_orbit_mat = IdentM44();
this.model_mat = Multiply(this.current_model_mat, this.model_mat);
this.current_model_mat = IdentM44();
};
this.OnMouseDown = function( event ) {
var rect = gl.canvas.getBoundingClientRect();
if ( event.clientX < rect.left || event.clientX > rect.right ) return;
if ( event.clientY < rect.top || event.clientY > rect.bottom ) return;
if (event.button == 0) { // left button
this.mouse_start = [event.clientX, event.clientY];
this.ChangeMotionMode( true, false, false );
}
};
this.OnMouseUp = function( event ) {
if (event.button == 0) { // left button
this.ChangeMotionMode( false, true, true );
} else if (event.button == 1) {// middle button
this.ChangeMotionMode( false, false, !this.auto_rotate );
}
};
this.OnMouseMove = function( event ) {
var dx = (event.clientX-this.mouse_start[0]) / this.vp[0];
var dy = (event.clientY-this.mouse_start[1]) / this.vp[1];
var len = Math.sqrt(dx*dx + dy*dy);
if (this.mouse_drag && len > 0) {
this.mouse_drag_angle = Math.PI*len;
this.mouse_drag_axis = [dy/len, 0, -dx/len];
this.mouse_drag_time = this.Time() - this.drag_start_T;
}
};
this.domElement = document;
var cam = this;
//this.domElement.addEventListener( 'contextmenu', function(e) { event.preventDefault(); }, false );
this.domElement.addEventListener( 'mousedown', function(e) { cam.OnMouseDown(e) }, false );
this.domElement.addEventListener( 'mouseup', function(e) { cam.OnMouseUp(e) }, false );
this.domElement.addEventListener( 'mousemove', function(e) { cam.OnMouseMove(e) }, false );
//this.domElement.addEventListener( 'mousewheel', hid_events.onMouseWheel, false );
//this.domElement.addEventListener( 'DOMMouseScroll', hid_events.onMouseWheel, false ); // firefox
}
var ShProg = {};
ShProg.Create = function( shaderList ) {
var shaderObjs = [];
for ( var i_sh = 0; i_sh < shaderList.length; ++ i_sh ) {
var shderObj = this.Compile( shaderList[i_sh].source, shaderList[i_sh].stage );
if ( shderObj == 0 )
return 0;
shaderObjs.push( shderObj );
}
var progObj = this.Link( shaderObjs )
if ( progObj != 0 ) {
progObj.attrInx = {};
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.attrInx[name] = gl.getAttribLocation( progObj, name );
}
progObj.uniLoc = {};
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.uniLoc[name] = gl.getUniformLocation( progObj, name );
}
}
return progObj;
}
ShProg.AttrI = function( progObj, name ) { return progObj.attrInx[name]; }
ShProg.UniformL = function( progObj, name ) { return progObj.uniLoc[name]; }
ShProg.Use = function( progObj ) { gl.useProgram( progObj ); }
ShProg.SetI1 = function( progObj, name, val ) { if(progObj.uniLoc[name]) gl.uniform1i( progObj.uniLoc[name], val ); }
ShProg.SetF1 = function( progObj, name, val ) { if(progObj.uniLoc[name]) gl.uniform1f( progObj.uniLoc[name], val ); }
ShProg.SetF2 = function( progObj, name, arr ) { if(progObj.uniLoc[name]) gl.uniform2fv( progObj.uniLoc[name], arr ); }
ShProg.SetF3 = function( progObj, name, arr ) { if(progObj.uniLoc[name]) gl.uniform3fv( progObj.uniLoc[name], arr ); }
ShProg.SetF4 = function( progObj, name, arr ) { if(progObj.uniLoc[name]) gl.uniform4fv( progObj.uniLoc[name], arr ); }
ShProg.SetM33 = function( progObj, name, mat ) { if(progObj.uniLoc[name]) gl.uniformMatrix3fv( progObj.uniLoc[name], false, mat ); }
ShProg.SetM44 = function( progObj, name, mat ) { if(progObj.uniLoc[name]) gl.uniformMatrix4fv( progObj.uniLoc[name], false, mat ); }
ShProg.Compile = 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;
}
ShProg.Link = 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 = {
Create: function(attribs, indices) {
var buffer = { buf: [], attr: [], inx: gl.createBuffer(), inxLen: indices.length };
for (var i=0; i<attribs.length; ++i) {
buffer.buf.push(gl.createBuffer());
buffer.attr.push({ size : attribs[i].attrSize, loc : attribs[i].attrLoc });
gl.bindBuffer(gl.ARRAY_BUFFER, buffer.buf[i]);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array( attribs[i].data ), gl.STATIC_DRAW);
}
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, buffer.inx);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array( indices ), gl.STATIC_DRAW);
gl.bindBuffer(gl.ARRAY_BUFFER, null);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, null);
return buffer;
},
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(bufObj.primitve_type ? bufObj.primitve_type : 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 { margin: 0; overflow: hidden; }
#gui { position : absolute; top : 0; left : 0; }<script id="draw-shader-vs" type="x-shader/x-vertex">
precision mediump 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_modelViewMat44;
void main()
{
vertNV = mat3( u_modelViewMat44 ) * normalize( inNV );
vertCol = inCol;
vec4 pos = u_modelViewMat44 * vec4( inPos, 1.0 );
vertPos = pos.xyz / pos.w;
gl_Position = u_projectionMat44 * pos;
}
</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;
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 * (0.2 + NdotH), 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="blur-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;
uniform float u_radius;
uniform vec2 u_dir;
float CalcGauss( float x, float sigma )
{
if ( sigma <= 0.0 )
return 0.0;
return exp( -(x*x) / (2.0 * sigma) ) / (2.0 * 3.14157 * sigma);
}
void main()
{
vec2 texC = pos.st * 0.5 + 0.5;
vec4 texCol = texture2D( u_texture, texC );
vec4 gaussCol = vec4( texCol.rgb, 1.0 );
vec2 step = u_dir / u_textureSize;
for ( int i = 1; i <= 32; ++ i )
{
float weight = CalcGauss( float(i) / 32.0, u_sigma * 0.5 );
if ( weight < 1.0/255.0 )
break;
texCol = texture2D( u_texture, texC + u_radius * step * float(i) );
gaussCol += vec4( texCol.rgb * weight, weight );
texCol = texture2D( u_texture, texC - u_radius * step * float(i) );
gaussCol += vec4( texCol.rgb * weight, weight );
}
gaussCol.rgb = clamp( gaussCol.rgb / gaussCol.w, 0.0, 1.0 );
gl_FragColor = vec4( gaussCol.rgb, 1.0 );
}
</script>
<div>
<form id="gui" name="inputs">
<table>
<tr> <td> <font color= #CCF>radius</font> </td>
<td> <input type="range" id="radius" min="1" max="1000" value="350" onchange="changeEventHandler(event);"/></td> </tr>
<tr> <td> <font color= #CCF>blur</font> </td>
<td> <input type="range" id="sigma" min="1" max="100" value="5" onchange="changeEventHandler(event);"/></td> </tr>
</table>
</form>
</div>
<canvas id="canvas" style="border: none;"></canvas>