RenderEncoder

Source

index.js
import * as macro from 'vtk.js/Sources/macros';
import vtkWebGPUShaderCache from 'vtk.js/Sources/Rendering/WebGPU/ShaderCache';

// methods we forward to the handle
const forwarded = [
'setBindGroup',
'setIndexBuffer',
'setVertexBuffer',
'draw',
'drawIndexed',
];

// ----------------------------------------------------------------------------
// vtkWebGPURenderEncoder methods
// ----------------------------------------------------------------------------
function vtkWebGPURenderEncoder(publicAPI, model) {
// Set our className
model.classHierarchy.push('vtkWebGPURenderEncoder');

publicAPI.begin = (encoder) => {
model.drawCallbacks = [];
model.handle = encoder.beginRenderPass(model.description);
if (model.label) {
model.handle.pushDebugGroup(model.label);
}
};

publicAPI.end = () => {
// loop over registered pipelines and their callbacks
for (let i = 0; i < model.drawCallbacks.length; i++) {
const pStruct = model.drawCallbacks[i];
const pl = pStruct.pipeline;

publicAPI.setPipeline(pl);

for (let cb = 0; cb < pStruct.callbacks.length; cb++) {
pStruct.callbacks[cb](publicAPI);
}
}
if (model.label) {
model.handle.popDebugGroup();
}
model.handle.end();
model.boundPipeline = null;
};

publicAPI.setPipeline = (pl) => {
if (model.boundPipeline === pl) {
return;
}
model.handle.setPipeline(pl.getHandle());
const pd = pl.getPipelineDescription();

// check attachment state
if (model.colorTextureViews.length !== pd.fragment.targets.length) {
console.log(
`mismatched attachment counts on pipeline ${pd.fragment.targets.length} while encoder has ${model.colorTextureViews.length}`
);
console.trace();
} else {
for (let i = 0; i < model.colorTextureViews.length; i++) {
const fmt = model.colorTextureViews[i].getTexture()?.getFormat();
if (fmt && fmt !== pd.fragment.targets[i].format) {
console.log(
`mismatched attachments for attachment ${i} on pipeline ${pd.fragment.targets[i].format} while encoder has ${fmt}`
);
console.trace();
}
}
}

// check depth buffer
if (!model.depthTextureView !== !('depthStencil' in pd)) {
console.log('mismatched depth attachments');
console.trace();
} else if (model.depthTextureView) {
const dfmt = model.depthTextureView.getTexture()?.getFormat();
if (dfmt && dfmt !== pd.depthStencil.format) {
console.log(
`mismatched depth attachments on pipeline ${pd.depthStencil.format} while encoder has ${dfmt}`
);
console.trace();
}
}
model.boundPipeline = pl;
};

publicAPI.replaceShaderCode = (pipeline) => {
model.replaceShaderCodeFunction(pipeline);
};

publicAPI.setColorTextureView = (idx, view) => {
if (model.colorTextureViews[idx] === view) {
return;
}
model.colorTextureViews[idx] = view;
};

publicAPI.activateBindGroup = (bg) => {
const device = model.boundPipeline.getDevice();
const midx = model.boundPipeline.getBindGroupLayoutCount(bg.getLabel());
model.handle.setBindGroup(midx, bg.getBindGroup(device));
// verify bind group layout matches
const bgl1 = device.getBindGroupLayoutDescription(
bg.getBindGroupLayout(device)
);
const bgl2 = device.getBindGroupLayoutDescription(
model.boundPipeline.getBindGroupLayout(midx)
);
if (bgl1 !== bgl2) {
console.log(
`renderEncoder ${model.pipelineHash} mismatched bind group layouts bind group has\n${bgl1}\n versus pipeline\n${bgl2}\n`
);
console.trace();
}
};

publicAPI.attachTextureViews = () => {
// for each texture create a view if we do not already have one
for (let i = 0; i < model.colorTextureViews.length; i++) {
if (!model.description.colorAttachments[i]) {
model.description.colorAttachments[i] = {
view: model.colorTextureViews[i].getHandle(),
};
} else {
model.description.colorAttachments[i].view =
model.colorTextureViews[i].getHandle();
}
}
if (model.depthTextureView) {
model.description.depthStencilAttachment.view =
model.depthTextureView.getHandle();
}
};

// register pipeline callbacks from a mapper
publicAPI.registerDrawCallback = (pipeline, cb) => {
// if there is a matching pipeline just add the cb
for (let i = 0; i < model.drawCallbacks.length; i++) {
if (model.drawCallbacks[i].pipeline === pipeline) {
model.drawCallbacks[i].callbacks.push(cb);
return;
}
}

model.drawCallbacks.push({ pipeline, callbacks: [cb] });
};

// simple forwarders
for (let i = 0; i < forwarded.length; i++) {
publicAPI[forwarded[i]] = (...args) => model.handle[forwarded[i]](...args);
}
}

// ----------------------------------------------------------------------------
// Object factory
// ----------------------------------------------------------------------------
const DEFAULT_VALUES = {
description: null,
handle: null,
boundPipeline: null,
pipelineHash: null,
pipelineSettings: null,
replaceShaderCodeFunction: null,
depthTextureView: null,
label: null,
};

// ----------------------------------------------------------------------------
export function extend(publicAPI, model, initialValues = {}) {
Object.assign(model, DEFAULT_VALUES, initialValues);

// Build VTK API
macro.obj(publicAPI, model);

model.description = {
colorAttachments: [
{
view: undefined,
loadOp: 'load',
storeOp: 'store',
},
],
depthStencilAttachment: {
view: undefined,
depthLoadOp: 'clear',
depthClearValue: 0.0,
depthStoreOp: 'store',
},
};

// default shader code just writes out the computedColor
model.replaceShaderCodeFunction = (pipeline) => {
const fDesc = pipeline.getShaderDescription('fragment');
fDesc.addOutput('vec4<f32>', 'outColor');
let code = fDesc.getCode();
code = vtkWebGPUShaderCache.substitute(code, '//VTK::RenderEncoder::Impl', [
'output.outColor = computedColor;',
]).result;
fDesc.setCode(code);
};

// default pipeline settings
model.pipelineSettings = {
primitive: { cullMode: 'none' },
depthStencil: {
depthWriteEnabled: true,
depthCompare: 'greater-equal',
format: 'depth32float',
},
fragment: {
targets: [
{
format: 'rgba16float',
blend: {
color: {
srcFactor: 'src-alpha',
dstFactor: 'one-minus-src-alpha',
},
alpha: { srcfactor: 'one', dstFactor: 'one-minus-src-alpha' },
},
},
],
},
};

model.colorTextureViews = [];

macro.get(publicAPI, model, ['boundPipeline', 'colorTextureViews']);

macro.setGet(publicAPI, model, [
'depthTextureView',
'description',
'handle',
'label',
'pipelineHash',
'pipelineSettings',
'replaceShaderCodeFunction',
]);

// For more macro methods, see "Sources/macros.js"
// Object specific methods
vtkWebGPURenderEncoder(publicAPI, model);
}

// ----------------------------------------------------------------------------
export const newInstance = macro.newInstance(extend, 'vtkWebGPURenderEncoder');

// ----------------------------------------------------------------------------
export default { newInstance, extend };