import {
Camera,
ClampToEdgeWrapping,
DataTexture,
FloatType,
Mesh,
NearestFilter,
PlaneGeometry,
RGBAFormat,
Scene,
ShaderMaterial,
WebGLRenderTarget
} from '../../../build/three.module.js';
/**
* 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
* const gpuCompute = new GPUComputationRenderer( 1024, 1024, renderer );
*
* // Create initial state float textures
* const pos0 = gpuCompute.createTexture();
* const vel0 = gpuCompute.createTexture();
* // and fill in here the texture data...
*
* // Add texture variables
* const velVar = gpuCompute.addVariable( "textureVelocity", fragmentShaderVel, pos0 );
* const 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
* const 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.
*
* const myFilter1 = gpuCompute.createShaderMaterial( myFilterFragmentShader1, { theTexture: { value: null } } );
* const myFilter2 = gpuCompute.createShaderMaterial( myFilterFragmentShader2, { theTexture: { value: null } } );
*
* const inputTexture = gpuCompute.createTexture();
*
* // Fill in here inputTexture...
*
* myFilter1.uniforms.theTexture.value = inputTexture;
*
* const myRenderTarget = gpuCompute.createRenderTarget();
* myFilter2.uniforms.theTexture.value = myRenderTarget.texture;
*
* const 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
*/
class GPUComputationRenderer {
constructor( sizeX, sizeY, renderer ) {
this.variables = [];
this.currentTextureIndex = 0;
let dataType = FloatType;
const scene = new Scene();
const camera = new Camera();
camera.position.z = 1;
const passThruUniforms = {
passThruTexture: { value: null }
};
const passThruShader = createShaderMaterial( getPassThroughFragmentShader(), passThruUniforms );
const mesh = new Mesh( new PlaneGeometry( 2, 2 ), passThruShader );
scene.add( mesh );
this.setDataType = function ( type ) {
dataType = type;
return this;
};
this.addVariable = function ( variableName, computeFragmentShader, initialValueTexture ) {
const material = this.createShaderMaterial( computeFragmentShader );
const 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.capabilities.isWebGL2 === false && renderer.extensions.has( 'OES_texture_float' ) === false ) {
return 'No OES_texture_float support for float textures.';
}
if ( renderer.capabilities.maxVertexTextures === 0 ) {
return 'No support for vertex shader textures.';
}
for ( let i = 0; i < this.variables.length; i ++ ) {
const 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
const material = variable.material;
const uniforms = material.uniforms;
if ( variable.dependencies !== null ) {
for ( let d = 0; d < variable.dependencies.length; d ++ ) {
const depVar = variable.dependencies[ d ];
if ( depVar.name !== variable.name ) {
// Checks if variable exists
let found = false;
for ( let 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 () {
const currentTextureIndex = this.currentTextureIndex;
const nextTextureIndex = this.currentTextureIndex === 0 ? 1 : 0;
for ( let i = 0, il = this.variables.length; i < il; i ++ ) {
const variable = this.variables[ i ];
// Sets texture dependencies uniforms
if ( variable.dependencies !== null ) {
const uniforms = variable.material.uniforms;
for ( let d = 0, dl = variable.dependencies.length; d < dl; d ++ ) {
const 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 || {};
const 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;
const renderTarget = new WebGLRenderTarget( sizeXTexture, sizeYTexture, {
wrapS: wrapS,
wrapT: wrapT,
minFilter: minFilter,
magFilter: magFilter,
format: RGBAFormat,
type: dataType,
depthBuffer: false
} );
return renderTarget;
};
this.createTexture = function () {
const data = new Float32Array( sizeX * sizeY * 4 );
return new DataTexture( data, sizeX, sizeY, RGBAFormat, FloatType );
};
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 ) {
const 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 };