/**
* @author yomboprime https://github.com/yomboprime
*
* GPUComputationRenderer, based on SimulationRenderer by zz85
*
* The GPUComputationRenderer uses the concept of variables. These variables are RGBA float textures that hold 4 floats
* for each compute element (texel)
*
* Each variable has a fragment shader that defines the computation made to obtain the variable in question.
* You can use as many variables you need, and make dependencies so you can use textures of other variables in the shader
* (the sampler uniforms are added automatically) Most of the variables will need themselves as dependency.
*
* The renderer has actually two render targets per variable, to make ping-pong. Textures from the current frame are used
* as inputs to render the textures of the next frame.
*
* The render targets of the variables can be used as input textures for your visualization shaders.
*
* Variable names should be valid identifiers and should not collide with THREE GLSL used identifiers.
* a common approach could be to use 'texture' prefixing the variable name; i.e texturePosition, textureVelocity...
*
* The size of the computation (sizeX * sizeY) is defined as 'resolution' automatically in the shader. For example:
* #DEFINE resolution vec2( 1024.0, 1024.0 )
*
* -------------
*
* Basic use:
*
* // Initialization...
*
* // Create computation renderer
* var gpuCompute = new GPUComputationRenderer( 1024, 1024, renderer );
*
* // Create initial state float textures
* var pos0 = gpuCompute.createTexture();
* var vel0 = gpuCompute.createTexture();
* // and fill in here the texture data...
*
* // Add texture variables
* var velVar = gpuCompute.addVariable( "textureVelocity", fragmentShaderVel, pos0 );
* var posVar = gpuCompute.addVariable( "texturePosition", fragmentShaderPos, vel0 );
*
* // Add variable dependencies
* gpuCompute.setVariableDependencies( velVar, [ velVar, posVar ] );
* gpuCompute.setVariableDependencies( posVar, [ velVar, posVar ] );
*
* // Add custom uniforms
* velVar.material.uniforms.time = { value: 0.0 };
*
* // Check for completeness
* var error = gpuCompute.init();
* if ( error !== null ) {
* console.error( error );
* }
*
*
* // In each frame...
*
* // Compute!
* gpuCompute.compute();
*
* // Update texture uniforms in your visualization materials with the gpu renderer output
* myMaterial.uniforms.myTexture.value = gpuCompute.getCurrentRenderTarget( posVar ).texture;
*
* // Do your rendering
* renderer.render( myScene, myCamera );
*
* -------------
*
* Also, you can use utility functions to create ShaderMaterial and perform computations (rendering between textures)
* Note that the shaders can have multiple input textures.
*
* var myFilter1 = gpuCompute.createShaderMaterial( myFilterFragmentShader1, { theTexture: { value: null } } );
* var myFilter2 = gpuCompute.createShaderMaterial( myFilterFragmentShader2, { theTexture: { value: null } } );
*
* var inputTexture = gpuCompute.createTexture();
*
* // Fill in here inputTexture...
*
* myFilter1.uniforms.theTexture.value = inputTexture;
*
* var myRenderTarget = gpuCompute.createRenderTarget();
* myFilter2.uniforms.theTexture.value = myRenderTarget.texture;
*
* var outputRenderTarget = gpuCompute.createRenderTarget();
*
* // Now use the output texture where you want:
* myMaterial.uniforms.map.value = outputRenderTarget.texture;
*
* // And compute each frame, before rendering to screen:
* gpuCompute.doRenderTarget( myFilter1, myRenderTarget );
* gpuCompute.doRenderTarget( myFilter2, outputRenderTarget );
*
*
*
* @param {int} sizeX Computation problem size is always 2d: sizeX * sizeY elements.
* @param {int} sizeY Computation problem size is always 2d: sizeX * sizeY elements.
* @param {WebGLRenderer} renderer The renderer
*/
import {
Camera,
ClampToEdgeWrapping,
DataTexture,
FloatType,
HalfFloatType,
Mesh,
NearestFilter,
PlaneBufferGeometry,
RGBAFormat,
Scene,
ShaderMaterial,
WebGLRenderTarget
} from "../../../build/three.module.js";
var GPUComputationRenderer = function ( sizeX, sizeY, renderer ) {
this.variables = [];
this.currentTextureIndex = 0;
var scene = new Scene();
var camera = new Camera();
camera.position.z = 1;
var passThruUniforms = {
passThruTexture: { value: null }
};
var passThruShader = createShaderMaterial( getPassThroughFragmentShader(), passThruUniforms );
var mesh = new Mesh( new PlaneBufferGeometry( 2, 2 ), passThruShader );
scene.add( mesh );
this.addVariable = function ( variableName, computeFragmentShader, initialValueTexture ) {
var material = this.createShaderMaterial( computeFragmentShader );
var variable = {
name: variableName,
initialValueTexture: initialValueTexture,
material: material,
dependencies: null,
renderTargets: [],
wrapS: null,
wrapT: null,
minFilter: NearestFilter,
magFilter: NearestFilter
};
this.variables.push( variable );
return variable;
};
this.setVariableDependencies = function ( variable, dependencies ) {
variable.dependencies = dependencies;
};
this.init = function () {
if ( ! renderer.extensions.get( "OES_texture_float" ) &&
! renderer.capabilities.isWebGL2 ) {
return "No OES_texture_float support for float textures.";
}
if ( renderer.capabilities.maxVertexTextures === 0 ) {
return "No support for vertex shader textures.";
}
for ( var i = 0; i < this.variables.length; i ++ ) {
var variable = this.variables[ i ];
// Creates rendertargets and initialize them with input texture
variable.renderTargets[ 0 ] = this.createRenderTarget( sizeX, sizeY, variable.wrapS, variable.wrapT, variable.minFilter, variable.magFilter );
variable.renderTargets[ 1 ] = this.createRenderTarget( sizeX, sizeY, variable.wrapS, variable.wrapT, variable.minFilter, variable.magFilter );
this.renderTexture( variable.initialValueTexture, variable.renderTargets[ 0 ] );
this.renderTexture( variable.initialValueTexture, variable.renderTargets[ 1 ] );
// Adds dependencies uniforms to the ShaderMaterial
var material = variable.material;
var uniforms = material.uniforms;
if ( variable.dependencies !== null ) {
for ( var d = 0; d < variable.dependencies.length; d ++ ) {
var depVar = variable.dependencies[ d ];
if ( depVar.name !== variable.name ) {
// Checks if variable exists
var found = false;
for ( var j = 0; j < this.variables.length; j ++ ) {
if ( depVar.name === this.variables[ j ].name ) {
found = true;
break;
}
}
if ( ! found ) {
return "Variable dependency not found. Variable=" + variable.name + ", dependency=" + depVar.name;
}
}
uniforms[ depVar.name ] = { value: null };
material.fragmentShader = "\nuniform sampler2D " + depVar.name + ";\n" + material.fragmentShader;
}
}
}
this.currentTextureIndex = 0;
return null;
};
this.compute = function () {
var currentTextureIndex = this.currentTextureIndex;
var nextTextureIndex = this.currentTextureIndex === 0 ? 1 : 0;
for ( var i = 0, il = this.variables.length; i < il; i ++ ) {
var variable = this.variables[ i ];
// Sets texture dependencies uniforms
if ( variable.dependencies !== null ) {
var uniforms = variable.material.uniforms;
for ( var d = 0, dl = variable.dependencies.length; d < dl; d ++ ) {
var depVar = variable.dependencies[ d ];
uniforms[ depVar.name ].value = depVar.renderTargets[ currentTextureIndex ].texture;
}
}
// Performs the computation for this variable
this.doRenderTarget( variable.material, variable.renderTargets[ nextTextureIndex ] );
}
this.currentTextureIndex = nextTextureIndex;
};
this.getCurrentRenderTarget = function ( variable ) {
return variable.renderTargets[ this.currentTextureIndex ];
};
this.getAlternateRenderTarget = function ( variable ) {
return variable.renderTargets[ this.currentTextureIndex === 0 ? 1 : 0 ];
};
function addResolutionDefine( materialShader ) {
materialShader.defines.resolution = 'vec2( ' + sizeX.toFixed( 1 ) + ', ' + sizeY.toFixed( 1 ) + " )";
}
this.addResolutionDefine = addResolutionDefine;
// The following functions can be used to compute things manually
function createShaderMaterial( computeFragmentShader, uniforms ) {
uniforms = uniforms || {};
var material = new ShaderMaterial( {
uniforms: uniforms,
vertexShader: getPassThroughVertexShader(),
fragmentShader: computeFragmentShader
} );
addResolutionDefine( material );
return material;
}
this.createShaderMaterial = createShaderMaterial;
this.createRenderTarget = function ( sizeXTexture, sizeYTexture, wrapS, wrapT, minFilter, magFilter ) {
sizeXTexture = sizeXTexture || sizeX;
sizeYTexture = sizeYTexture || sizeY;
wrapS = wrapS || ClampToEdgeWrapping;
wrapT = wrapT || ClampToEdgeWrapping;
minFilter = minFilter || NearestFilter;
magFilter = magFilter || NearestFilter;
var renderTarget = new WebGLRenderTarget( sizeXTexture, sizeYTexture, {
wrapS: wrapS,
wrapT: wrapT,
minFilter: minFilter,
magFilter: magFilter,
format: RGBAFormat,
type: ( /(iPad|iPhone|iPod)/g.test( navigator.userAgent ) ) ? HalfFloatType : FloatType,
stencilBuffer: false,
depthBuffer: false
} );
return renderTarget;
};
this.createTexture = function () {
var a = new Float32Array( sizeX * sizeY * 4 );
var texture = new DataTexture( a, sizeX, sizeY, RGBAFormat, FloatType );
texture.needsUpdate = true;
return texture;
};
this.renderTexture = function ( input, output ) {
// Takes a texture, and render out in rendertarget
// input = Texture
// output = RenderTarget
passThruUniforms.passThruTexture.value = input;
this.doRenderTarget( passThruShader, output );
passThruUniforms.passThruTexture.value = null;
};
this.doRenderTarget = function ( material, output ) {
var currentRenderTarget = renderer.getRenderTarget();
mesh.material = material;
renderer.setRenderTarget( output );
renderer.render( scene, camera );
mesh.material = passThruShader;
renderer.setRenderTarget( currentRenderTarget );
};
// Shaders
function getPassThroughVertexShader() {
return "void main() {\n" +
"\n" +
" gl_Position = vec4( position, 1.0 );\n" +
"\n" +
"}\n";
}
function getPassThroughFragmentShader() {
return "uniform sampler2D passThruTexture;\n" +
"\n" +
"void main() {\n" +
"\n" +
" vec2 uv = gl_FragCoord.xy / resolution.xy;\n" +
"\n" +
" gl_FragColor = texture2D( passThruTexture, uv );\n" +
"\n" +
"}\n";
}
};
export { GPUComputationRenderer };
