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<!--
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<!--
This sample shows how to create a separable convolution shader using
render targets. The kernel here is a Gaussian blur, but the same code
could be used for any kernel.
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>
O3D: Convolution Shader Sample
</title>
<!-- Include sample javascript library functions-->
<script type="text/javascript" src="o3djs/base.js"></script>
<script type="text/javascript" id="o3dscript">
o3djs.require('o3djs.util');
o3djs.require('o3djs.math');
o3djs.require('o3djs.camera');
o3djs.require('o3djs.rendergraph');
o3djs.require('o3djs.pack');
o3djs.require('o3djs.primitives');
o3djs.require('o3djs.scene');
// Events
// init() once the page has finished loading.
window.onload = init;
window.onunload = uninit;
// constants.
var RENDER_TARGET_WIDTH = 512;
var RENDER_TARGET_HEIGHT = 512;
// global variables
var g_o3d;
var g_client;
var g_math;
var g_pack;
var g_teapotRoot;
var g_renderGraphRoot;
var g_clock = 0;
var g_timeMult = 1;
var g_finished = false; // for selenium testing.
/**
* Loads a scene into the transform graph.
* @param {!o3d.Pack} pack Pack to load scene into.
* @param {string} fileName filename of the scene.
* @param {!o3d.Transform} parent parent node in the transform graph to
* which to load the scene into.
* @param {!o3djs.rendergraph.ViewInfo} viewInfo whose view and projection will
* be set from the scene after it's loaded.
*/
function loadScene(pack, fileName, parent, viewInfo) {
// Get our full path to the scene.
var scenePath = o3djs.util.getCurrentURI() + fileName;
// Load the scene given the full path, and call the callback function
// when its done loading.
o3djs.scene.loadScene(g_client, pack, parent, scenePath, callback);
/**
* Our callback is called once the scene has been loaded into memory from the
* web or locally.
* @param {!o3d.Pack} pack The pack that was passed in above.
* @param {!o3d.Transform} parent The parent that was passed in above.
* @param {*} exception null if loading succeeded.
*/
function callback(pack, parent, exception) {
if (exception) {
alert('Could not load: ' + fileName + '\n' + exception);
return;
}
// Get a CameraInfo (an object with a view and projection matrix)
// using our javascript library function
var cameraInfo = o3djs.camera.getViewAndProjectionFromCameras(
parent,
RENDER_TARGET_WIDTH,
RENDER_TARGET_HEIGHT);
// Copy the view and projection to the passed in viewInfo structure..
viewInfo.drawContext.view = cameraInfo.view;
viewInfo.drawContext.projection = cameraInfo.projection;
// Generate draw elements and setup material draw lists.
o3djs.pack.preparePack(pack, viewInfo);
g_finished = true; // for selenium testing.
}
}
/**
* Creates the client area.
*/
function init() {
o3djs.util.makeClients(initStep2);
}
/**
* Initializes O3D and loads the scene into the transform graph.
* @param {Array} clientElements Array of o3d object elements.
*/
function initStep2(clientElements) {
// Initializes global variables and libraries.
var o3d = clientElements[0];
g_o3d = o3d.o3d;
g_math = o3djs.math;
g_client = o3d.client;
// Creates a pack to manage our resources/assets.
g_pack = g_client.createPack();
// Create the texture required for the color render-target.
var texture1 = g_pack.createTexture2D(RENDER_TARGET_WIDTH,
RENDER_TARGET_HEIGHT,
g_o3d.Texture.XRGB8, 1, true);
// Create the texture required for the color render-target.
var texture2 = g_pack.createTexture2D(RENDER_TARGET_WIDTH,
RENDER_TARGET_HEIGHT,
g_o3d.Texture.XRGB8, 1, true);
g_teapotRoot = g_pack.createObject('Transform');
var renderGraphRoot = g_client.renderGraphRoot;
var xSigma = 4.0, ySigma = 4.0;
var xKernel = buildKernel(xSigma);
var yKernel = buildKernel(ySigma);
var renderSurfaceSet1 = createRenderSurfaceSet(texture1);
var renderSurfaceSet2 = createRenderSurfaceSet(texture2);
// Create the render graph for the teapot view, drawing the teapot into
// texture1 (via renderSurfaceSet1).
var teapotViewInfo = o3djs.rendergraph.createBasicView(
g_pack,
g_teapotRoot,
renderSurfaceSet1,
[1, 1, 1, 1]);
// Create a Y convolution pass that convolves texture1 into texture2, using
// the X kernel.
var renderNode1 = createConvolutionPass(texture1,
renderSurfaceSet2,
xKernel,
1.0 / texture1.width,
0.0);
// Create a Y convolution pass that convolves texture2 into the framebuffer,
// using the Y kernel.
var renderNode2 = createConvolutionPass(texture2,
g_client.renderGraphRoot,
yKernel,
0.0,
1.0 / texture2.height);
// Load the scene into the transform graph as a child g_teapotRoot
loadScene(g_pack, 'assets/teapot.o3dtgz', g_teapotRoot, teapotViewInfo);
// Set a render callback.
g_client.setRenderCallback(onRender);
}
// We lop off the sqrt(2 * pi) * sigma term, since we're going to normalize
// anyway.
function gauss(x, sigma) {
return Math.exp(- (x * x) / (2.0 * sigma * sigma));
}
function buildKernel(sigma) {
var kMaxKernelSize = 25;
var kernelSize = 2 * Math.ceil(sigma * 3.0) + 1;
if (kernelSize > kMaxKernelSize) {
kernelSize = kMaxKernelSize;
}
var halfWidth = (kernelSize - 1) * 0.5
var values = new Array(kernelSize);
var sum = 0.0;
for (var i = 0; i < kernelSize; ++i) {
values[i] = gauss(i - halfWidth, sigma);
sum += values[i];
}
// Now normalize the kernel.
for (var i = 0; i < kernelSize; ++i) {
values[i] /= sum;
}
return values;
}
function createConvolutionMaterial(viewInfo, kernelSize) {
var convFXString = document.getElementById('convFX').value;
convFXString = convFXString.replace(/KERNEL_WIDTH/g, kernelSize);
var convEffect = g_pack.createObject('Effect');
convEffect.loadFromFXString(convFXString);
var convMaterial = g_pack.createObject('Material');
convMaterial.drawList = viewInfo.performanceDrawList;
convMaterial.effect = convEffect;
convEffect.createUniformParameters(convMaterial);
return convMaterial;
}
function createRenderSurfaceSet(texture) {
var renderSurface = texture.getRenderSurface(0);
// Create the depth-stencil buffer required when rendering this pass.
var depthSurface = g_pack.createDepthStencilSurface(RENDER_TARGET_WIDTH,
RENDER_TARGET_HEIGHT);
var renderSurfaceSet = g_pack.createObject('RenderSurfaceSet');
renderSurfaceSet.renderSurface = renderSurface;
renderSurfaceSet.renderDepthStencilSurface = depthSurface;
renderSurfaceSet.parent = g_client.renderGraphRoot;
return renderSurfaceSet;
}
function createConvolutionPass(srcTexture, renderGraphRoot, kernel, x, y) {
// Create a root Transform for the convolution scene.
var root = g_pack.createObject('Transform');
// Create a basic view for the convolution scene.
var viewInfo = o3djs.rendergraph.createBasicView(
g_pack,
root,
renderGraphRoot,
[1, 1, 1, 1]);
var material = createConvolutionMaterial(viewInfo, kernel.length);
var quadShape = o3djs.primitives.createPlane(g_pack,
material,
2.0,
2.0,
1,
1);
// Attach the quad to the root of the convolution graph.
root.addShape(quadShape);
// Rotate the view so we're looking at the XZ plane (where our quad is)
// Point the camera along the -Y axis
var target = [0, -1, 0];
// Put the camera at the origin.
var eye = [0, 0, 0];
// Define the up-vector as +Z
var up = [0, 0, 1];
viewInfo.drawContext.view = g_math.matrix4.lookAt(eye, target, up);
// Create an orthographic projection.
viewInfo.drawContext.projection = g_math.matrix4.orthographic(-1, 1, -1, 1, -1, 1);
// Generate draw elements and setup material draw lists for the
// convolution scene.
o3djs.pack.preparePack(g_pack, viewInfo);
setConvolutionParameters(material, srcTexture, kernel, kernel.length, x, y);
return renderGraphRoot;
}
function setConvolutionParameters(material, texture, kernel, kernelSize,
xIncrement, yIncrement) {
var imageParam = material.getParam('image');
var kernelParam = material.getParam('kernel');
var imageIncrement = material.getParam('imageIncrement');
var sampler = g_pack.createObject('Sampler');
sampler.texture = texture;
sampler.addressModeU = g_o3d.Sampler.CLAMP;
sampler.addressModeV = g_o3d.Sampler.CLAMP;
sampler.minFilter = g_o3d.Sampler.POINT;
sampler.magFilter = g_o3d.Sampler.POINT;
sampler.mipFilter = g_o3d.Sampler.NONE;
imageParam.value = sampler;
imageIncrement.value = [xIncrement, yIncrement];
var paramArray = g_pack.createObject('ParamArray');
var halfWidth = (kernelSize - 1) * 0.5;
for (var i = 0; i < kernelSize; ++i) {
var element = paramArray.createParam(i, 'ParamFloat');
element.value = kernel[i];
}
kernelParam.value = paramArray;
}
/**
* Called every frame.
* @param {o3d.RenderEvent} renderEvent Rendering Information.
*/
function onRender(renderEvent) {
var elapsedTime = renderEvent.elapsedTime;
g_clock += elapsedTime * g_timeMult;
g_teapotRoot.identity();
g_teapotRoot.rotateX(g_clock);
g_teapotRoot.rotateY(g_clock * 1.3);
}
/**
* Cleanup before exiting.
*/
function uninit() {
if (g_client) {
g_client.cleanup();
}
}
</script>
</head>
<body>
<h1>Convolution Shader Example</h1>
<p>This sample shows how to do 2D image processing using render targets. This
sample uses a convolution shader to do a 2D Gaussian blur, but the
same code could be used for any separable convolution kernel.</p>
<br/>
<!-- Start of O3D plugin -->
<div id="o3d" style="width: 512px; height: 512px;"></div>
<!-- End of O3D plugin -->
<!--
We embed the code for our effect inside this hidden textarea.
Effects contain the functions that define
the vertex and pixel shaders used by our shape.
-->
<!-- Don't render the textarea -->
<div style="display:none">
<textarea id="convFX" name="convFX" cols="80" rows="20">
float4x4 worldViewProjection : WorldViewProjection;
sampler2D image;
float kernel[KERNEL_WIDTH];
float2 imageIncrement;
struct VertexShaderInput {
float4 position : POSITION;
float2 imageCoord : TEXCOORD0;
};
struct PixelShaderInput {
float4 position : POSITION;
float2 imageCoord : TEXCOORD0;
};
PixelShaderInput ConvolutionVS(VertexShaderInput input) {
PixelShaderInput output;
output.position = mul(input.position, worldViewProjection);
// Offset image coords by half of kernel width, in image texels
output.imageCoord = input.imageCoord -
((KERNEL_WIDTH - 1) / 2) * imageIncrement;
return output;
}
float4 ConvolutionPS(PixelShaderInput input) : COLOR {
float2 imageCoord = input.imageCoord;
float4 sum = float4(0.0, 0.0, 0.0, 0.0);
for (int i = 0; i < KERNEL_WIDTH; ++i) {
sum += tex2D(image, imageCoord) * kernel[i];
imageCoord += imageIncrement;
}
return sum;
}
// #o3d VertexShaderEntryPoint ConvolutionVS
// #o3d PixelShaderEntryPoint ConvolutionPS
// #o3d MatrixLoadOrder RowMajor
</textarea>
</div>
</body>
</html>
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