@strawberry-vis/g-device-api v1.2.0
@strawberry-vis/g-device-api
This is a set of Device API also known as the hardware adaptation layer(HAL). It is implemented using WebGL1/2 & WebGPU underneath and inspired by noclip.
Installing
npm install @strawberry-vis/g-device-apiAPI Reference
- [Create a device](#createDevice)
Resource Creation
- [createBuffer](#createBuffer)
- [createTexture](#createTexture)
- [createSampler](#createSampler)
- [createRenderTarget](#createRenderTarget)
- [createRenderTargetFromTexture](#createRenderTargetFromTexture)
- [createProgram](#createProgram)
- [createBindings](#createBindings)
- [createInputLayout](#createInputLayout)
- [createRenderPipeline](#createRenderPipeline)
- [createComputePipeline](#createComputePipeline)
- [createReadback](#createReadback)
- [createQueryPool](#createQueryPool)
- [createRenderPass](#createRenderPass)
- [createComputePass](#createComputePass)
Submit
- [submitPass](#submitPass)
- [copySubTexture2D](#copySubTexture2D)
- Query
- [queryLimits](#queryLimits)
- [queryTextureFormatSupported](#queryTextureFormatSupported)
- [queryPlatformAvailable](#queryPlatformAvailable)
- [queryVendorInfo](#queryVendorInfo)
Debug
- [setResourceName](#setResourceName)
- [checkForLeaks](#checkForLeaks)
- [pushDebugGroup](#pushDebugGroup)
- [popDebugGroup](#popDebugGroup)
GPU Resources
- [Buffer](#buffer)
- [setSubData](#setSubData)
- [Texture](#texture)
- [setImageData](#setImageData)
- [Sampler](#sampler)
- [RenderTarget](#renderTarget)
- [RenderPass](#renderPass)
- [setViewport](#setViewport)
- [setScissorRect](#setScissorRect)
- [setPipeline](#setPipeline)
- [setBindings](#setBindings)
- [setVertexInput](#setVertexInput)
- [setStencilReference](#setStencilReference)
- [draw](#draw)
- [drawIndexed](#drawIndexed)
- [drawIndirect](#drawIndirect)
- [drawIndexedIndirect](#drawIndexedIndirect)
- [beginOcclusionQuery](#beginOcclusionQuery)
- [endOcclusionQuery](#endOcclusionQuery)
- [ComputePass](#computePass)
- [setPipeline](#setPipeline)
- [setBindings](#setBindings)
- [dispatchWorkgroups](#dispatchWorkgroups)
- [dispatchWorkgroupsIndirect](#dispatchWorkgroupsIndirect)
- Program
- [setUniformsLegacy](#setUniformsLegacy)
- QueryPool
- queryResultOcclusion
- [Readback](#readback)
- [readTexture](#readTexture)
- [readTextureSync](#readTextureSync)
- [readBuffer](#readBuffer)
- [Buffer](#buffer)
Create Device
A device is the logical instantiation of GPU.
import {
Device,
BufferUsage,
WebGLDeviceContribution,
WebGPUDeviceContribution,
} from '@strawberry-vis/g-device-api';
// Create a WebGL based device contribution.
const deviceContribution = new WebGLDeviceContribution({
targets: ['webgl2', 'webgl1'],
});
// Or create a WebGPU based device contribution.
const deviceContribution = new WebGPUDeviceContribution({
shaderCompilerPath: '/glsl_wgsl_compiler_bg.wasm',
});
const swapChain = await deviceContribution.createSwapChain($canvas);
swapChain.configureSwapChain(width, height);
const device = swapChain.getDevice();createBuffer
A [Buffer](#buffer) represents a block of memory that can be used in GPU operations. Data is stored in linear layout.
We references the [WebGPU design](https://www.w3.org/TR/webgpu/#dom-gpudevice-createbuffer):
createBuffer: (descriptor: BufferDescriptor) => Buffer;The parameters are as follows, references the [WebGPU design](https://www.w3.org/TR/webgpu/#GPUBufferDescriptor):
- viewOrSize
requiredSet buffer data directly or allocate fixed length(in bytes). - usage
requiredThe allowed usage for this buffer. - hint
optionalKnown as hint when calling [bufferData](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/bufferData#usage) in WebGL.
interface BufferDescriptor {
viewOrSize: ArrayBufferView | number;
usage: BufferUsage;
hint?: BufferFrequencyHint;
}We can set buffer data directly, or allocate fixed length for later use e.g. calling [setSubData](#setSubData):
const buffer = device.createBuffer({
viewOrSize: new Float32Array([1, 2, 3, 4]),
usage: BufferUsage.VERTEX,
});
// or
const buffer = device.createBuffer({
viewOrSize: 4 * Float32Array.BYTES_PER_ELEMENT, // in bytes
usage: BufferUsage.VERTEX,
});
buffer.setSubData(0, new Uint8Array(new Float32Array([1, 2, 3, 4]).buffer));The allowed [usage](https://www.w3.org/TR/webgpu/#dom-gpubuffer-usage) for buffer.
They can also be composited like BufferUsage.VERTEX | BufferUsage.STORAGE.
enum BufferUsage {
MAP_READ = 0x0001,
MAP_WRITE = 0x0002,
COPY_SRC = 0x0004,
COPY_DST = 0x0008,
INDEX = 0x0010,
VERTEX = 0x0020,
UNIFORM = 0x0040,
STORAGE = 0x0080,
INDIRECT = 0x0100,
QUERY_RESOLVE = 0x0200,
}This param is called [usage](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/bufferData#usage) in WebGL. We change its name to hint avoiding duplicate naming.
enum BufferFrequencyHint {
Static = 0x01,
Dynamic = 0x02,
}createTexture
This method references the [WebGPU design](https://developer.mozilla.org/en-US/docs/Web/API/GPUDevice/createTexture) to create a [Texture](#texture):
createTexture: (descriptor: TextureDescriptor) => Texture;The parameters are as follows, references the [WebGPU design](https://www.w3.org/TR/webgpu/#GPUBufferDescriptor):
interface TextureDescriptor {
usage: TextureUsage;
format: Format;
width: number;
height: number;
depthOrArrayLayers?: number;
dimension?: TextureDimension;
mipLevelCount?: number;
pixelStore?: Partial<{
packAlignment: number;
unpackAlignment: number;
unpackFlipY: boolean;
}>;
}- usage
requiredThe allowed usages for this GPUTexture. - format
requiredThe format of this GPUTexture. - width
requiredThe width of this GPUTexture. - height
requiredThe height of this GPUTexture. - depthOrArrayLayers
optionalThe depth or layer count of this GPUTexture. Default to1. - dimension
optionalThe dimension of the set of texel for each of this GPUTexture's subresources. Default toTextureDimension.TEXTURE_2D - mipLevelCount
optionalThe number of mip levels of this GPUTexture. Default to1. - pixelStore
optionalSpecifies the [pixel storage modes](https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/pixelStorei) in WebGL.- packAlignment Packing of pixel data into memory.
gl.PACK_ALIGNMENT - unpackAlignment Unpacking of pixel data from memory.
gl.UNPACK_ALIGNMENT - unpackFlipY Flips the source data along its vertical axis if true.
gl.UNPACK_FLIP_Y_WEBGL
- packAlignment Packing of pixel data into memory.
The TextureUsage enum is as follows:
enum TextureUsage {
SAMPLED,
RENDER_TARGET, // When rendering to texture, choose this usage.
}The TextureDimension enum is as follows:
enum TextureDimension {
TEXTURE_2D,
TEXTURE_2D_ARRAY,
TEXTURE_3D,
TEXTURE_CUBE_MAP,
}createSampler
[Samplers](#sampler) are created via createSampler().
createSampler: (descriptor: SamplerDescriptor) => Sampler;The params reference [GPUSamplerDescriptor](https://www.w3.org/TR/webgpu/#dictdef-gpusamplerdescriptor).
interface SamplerDescriptor {
addressModeU: AddressMode;
addressModeV: AddressMode;
addressModeW?: AddressMode;
minFilter: FilterMode;
magFilter: FilterMode;
mipmapFilter: MipmapFilterMode;
lodMinClamp?: number;
lodMaxClamp?: number;
maxAnisotropy?: number;
compareFunction?: CompareFunction;
}AddressMode describes the behavior of the sampler if the sample footprint extends beyond the bounds of the sampled texture.
enum AddressMode {
CLAMP_TO_EDGE,
REPEAT,
MIRRORED_REPEAT,
}FilterMode and MipmapFilterMode describe the behavior of the sampler if the sample footprint does not exactly match one texel.
enum FilterMode {
POINT,
BILINEAR,
}
enum MipmapFilterMode {
NO_MIP,
NEAREST,
LINEAR,
}CompareFunction specifies the behavior of a comparison sampler. If a comparison sampler is used in a shader, an input value is compared to the sampled texture value, and the result of this comparison test (0.0f for pass, or 1.0f for fail) is used in the filtering operation.
enum CompareFunction {
NEVER = GL.NEVER,
LESS = GL.LESS,
EQUAL = GL.EQUAL,
LEQUAL = GL.LEQUAL,
GREATER = GL.GREATER,
NOTEQUAL = GL.NOTEQUAL,
GEQUAL = GL.GEQUAL,
ALWAYS = GL.ALWAYS,
}createRenderTarget
createRenderTarget: (descriptor: RenderTargetDescriptor) => RenderTarget;interface RenderTargetDescriptor {
format: Format;
width: number;
height: number;
sampleCount: number;
texture?: Texture;
}createRenderTargetFromTexture
createRenderTargetFromTexture: (texture: Texture) => RenderTarget;createProgram
createProgram: (program: ProgramDescriptor) => Program;interface ProgramDescriptor {
vertex?: {
glsl?: string;
wgsl?: string;
};
fragment?: {
glsl?: string;
wgsl?: string;
};
compute?: {
wgsl: string;
};
}createBindings
createBindings: (bindingsDescriptor: BindingsDescriptor) => Bindings;interface BindingsDescriptor {
bindingLayout: BindingLayoutDescriptor;
pipeline?: RenderPipeline | ComputePipeline;
uniformBufferBindings?: BufferBinding[];
samplerBindings?: SamplerBinding[];
storageBufferBindings?: BufferBinding[];
}createInputLayout
InputLayout defines the layout of vertex attribute data in a vertex buffer used by pipeline.
createInputLayout: (inputLayoutDescriptor: InputLayoutDescriptor) =>
InputLayout;A vertex buffer is, conceptually, a view into buffer memory as an array of structures. arrayStride is the stride, in bytes, between elements of that array. Each element of a vertex buffer is like a structure with a memory layout defined by its attributes, which describe the members of the structure.
interface InputLayoutDescriptor {
vertexBufferDescriptors: (InputLayoutBufferDescriptor | null)[];
indexBufferFormat: Format | null;
program: Program;
}
interface InputLayoutBufferDescriptor {
arrayStride: number; // in bytes
stepMode: VertexStepMode; // per vertex or instance
attributes: VertexAttributeDescriptor[];
}
interface VertexAttributeDescriptor {
shaderLocation: number;
format: Format;
offset: number;
divisor?: number;
}- shaderLocation
requiredThe numeric location associated with this attribute, which will correspond with a "@location" attribute declared in the vertex.module. - format
requiredThe VertexFormat of the attribute. - offset
requiredThe offset, in bytes, from the beginning of the element to the data for the attribute. - divisor
optional
createReadback
Create a Readback to read GPU resouce's data from CPU side:
createReadback: () => Readback;readBuffer: (
b: Buffer,
srcByteOffset?: number,
dst?: ArrayBufferView,
dstOffset?: number,
length?: number,
) => Promise<ArrayBufferView>;const readback = device.createReadback();
readback.readBuffer(buffer);createQueryPool
Only WebGL 2 & WebGPU support:
createQueryPool: (type: QueryPoolType, elemCount: number) => QueryPool;queryResultOcclusion(dstOffs: number): boolean | nullcreateRenderPipeline
createRenderPipeline: (descriptor: RenderPipelineDescriptor) => RenderPipeline;createComputePipeline
createComputePipeline: (descriptor: ComputePipelineDescriptor) =>
ComputePipeline;type ComputePipelineDescriptor = PipelineDescriptor;
interface PipelineDescriptor {
bindingLayouts: BindingLayoutDescriptor[];
inputLayout: InputLayout | null;
program: Program;
}createRenderPass
createComputePass
⚠️Only WebGPU support.
createComputePass: () => ComputePass;submitPass
submitPass(o: RenderPass | ComputePass): void;copySubTexture2D
copySubTexture2D: (
dst: Texture,
dstX: number,
dstY: number,
src: Texture,
srcX: number,
srcY: number,
) => void;- ⚠️WebGL 1 not supported
- WebGL 2 uses [blitFramebuffer](https://developer.mozilla.org/en-US/docs/Web/API/WebGL2RenderingContext/blitFramebuffer)
- WebGPU uses [copyTextureToTexture](https://developer.mozilla.org/en-US/docs/Web/API/GPUCommandEncoder/copyTextureToTexture)
queryLimits
// @see https://www.w3.org/TR/webgpu/#gpusupportedlimits
queryLimits: () => DeviceLimits;interface DeviceLimits {
uniformBufferWordAlignment: number;
uniformBufferMaxPageWordSize: number;
supportedSampleCounts: number[];
occlusionQueriesRecommended: boolean;
computeShadersSupported: boolean;
}queryPlatformAvailable
Query whether device's context is already lost:
queryPlatformAvailable(): booleanWebGL / WebGPU will trigger Lost event:
device.queryPlatformAvailable(); // falsequeryTextureFormatSupported
queryTextureFormatSupported(format: Format, width: number, height: number): boolean;const shadowsSupported = device.queryTextureFormatSupported(
Format.U16_RG_NORM,
0,
0,
);queryVendorInfo
WebGL 1/2 & WebGPU use different origin:
queryVendorInfo: () => VendorInfo;interface VendorInfo {
readonly platformString: string;
readonly glslVersion: string;
readonly explicitBindingLocations: boolean;
readonly separateSamplerTextures: boolean;
readonly viewportOrigin: ViewportOrigin;
readonly clipSpaceNearZ: ClipSpaceNearZ;
readonly supportMRT: boolean;
}setResourceName
When using Spector.js to debug our application, we can set a name to relative GPU resource.
setResourceName: (o: Resource, s: string) => void;For instance, we add a label for RT and Spector.js will show us the metadata:
device.setResourceName(renderTarget, 'Main Render Target');On WebGPU devtools we can also see the label:
checkForLeaks
Checks if there is currently a leaking GPU resource. We keep track of every GPU resource object created, and calling this method prints the currently undestroyed object and the stack information where the resource was created on the console, making it easy to troubleshoot memory leaks.
It is recommended to call this when destroying the scene to determine if there are resources that have not been destroyed correctly. For example, in the image below, there is a WebGL Buffer that has not been destroyed:
We should call buffer.destroy() at this time to avoid OOM.
pushDebugGroup
<https://developer.mozilla.org/en-US/docs/Web/API/GPUCommandEncoder/pushDebugGroup>
pushDebugGroup(debugGroup: DebugGroup): void;interface DebugGroup {
name: string;
drawCallCount: number;
textureBindCount: number;
bufferUploadCount: number;
triangleCount: number;
}popDebugGroup
<https://developer.mozilla.org/en-US/docs/Web/API/GPUCommandEncoder/popDebugGroup>
Buffer
A Buffer represents a block of memory that can be used in GPU operations. Data is stored in linear layout.
setSubData
We can set data in buffer with this method:
- dstByteOffset
requiredOffset of dest buffer in bytes. - src
requiredSource buffer data, must use Uint8Array. - srcByteOffset
optionalOffset of src buffer in bytes. Default to0. - byteLength
optionalDefault to the whole length of the src buffer.
setSubData: (
dstByteOffset: number,
src: Uint8Array,
srcByteOffset?: number,
byteLength?: number,
) => void;Texture
One texture consists of one or more texture subresources, each uniquely identified by a mipmap level and, for 2d textures only, array layer and aspect.
setImageData
We can set data in buffer with this method:
- data
requiredArray of TexImageSource or ArrayBufferView. - lod
optionalLod. Default to0.
setImageData: (
data: (TexImageSource | ArrayBufferView)[],
lod?: number,
) => void;Create a cubemap texture:
// The order of the array layers is [+X, -X, +Y, -Y, +Z, -Z]
const imageBitmaps = await Promise.all(
[
'/images/posx.jpg',
'/images/negx.jpg',
'/images/posy.jpg',
'/images/negy.jpg',
'/images/posz.jpg',
'/images/negz.jpg',
].map(async (src) => loadImage(src)),
);
const texture = device.createTexture({
format: Format.U8_RGBA_NORM,
width: imageBitmaps[0].width,
height: imageBitmaps[0].height,
depthOrArrayLayers: 6,
dimension: TextureDimension.TEXTURE_CUBE_MAP,
usage: TextureUsage.SAMPLED,
});
texture.setImageData(imageBitmaps);Sampler
A GPUSampler encodes transformations and filtering information that can be used in a shader to interpret texture resource data.
RenderPass
The RenderPass has several methods which affect how draw commands.
setViewport
Sets the viewport used during the rasterization stage to linearly map from normalized device coordinates to viewport coordinates.
- x
requiredMinimum X value of the viewport in pixels. - y
requiredMinimum Y value of the viewport in pixels. - w
requiredWidth of the viewport in pixels. - h
requiredHeight of the viewport in pixels. - minDepth
optionalMinimum depth value of the viewport. - maxDepth
optionalMinimum depth value of the viewport.
setViewport: (
x: number,
y: number,
w: number,
h: number,
minDepth?: number, // WebGPU only
maxDepth?: number, // WebGPU only
) => void;setScissorRect
Sets the scissor rectangle used during the rasterization stage. After transformation into viewport coordinates any fragments which fall outside the scissor rectangle will be discarded.
- x
requiredMinimum X value of the scissor rectangle in pixels. - y
requiredMinimum Y value of the scissor rectangle in pixels. - w
requiredWidth of the scissor rectangle in pixels. - h
requiredHeight of the scissor rectangle in pixels.
setScissorRect: (x: number, y: number, w: number, h: number) => void;setPipeline
Sets the current RenderPipeline.
setPipeline(pipeline: RenderPipeline)setBindings
Bindings defines the interface between a set of resources bound and their accessibility in shader stages.
setBindings: (bindings: Bindings) => void;setVertexInput
setVertexInput: (
inputLayout: InputLayout | null,
buffers: (VertexBufferDescriptor | null)[] | null,
indexBuffer: IndexBufferDescriptor | null,
) => void;Bind vertex & index buffer(s) like this:
interface VertexBufferDescriptor {
buffer: Buffer;
offset?: number; // in bytes
}
type IndexBufferDescriptor = VertexBufferDescriptor;setStencilReference
Sets the stencilReference value used during stencil tests with the "replace" GPUStencilOperation.
setStencilReference: (value: number) => void;draw
Draws primitives.
- vertexCount
requiredThe number of vertices to draw. - instanceCount
optionalThe number of instances to draw. - firstVertex
optionalOffset into the vertex buffers, in vertices, to begin drawing from. - firstInstance
optionalFirst instance to draw.
draw: (
vertexCount: number,
instanceCount?: number,
firstVertex?: number,
firstInstance?: number,
) => void;drawIndexed
Draws indexed primitives.
- indexCount
requiredThe number of indices to draw. - instanceCount
optionalThe number of instances to draw. - firstIndex
optionalOffset into the index buffer, in indices, begin drawing from. - baseVertex
optionalAdded to each index value before indexing into the vertex buffers. - firstInstance
optionalFirst instance to draw.
drawIndexed: (
indexCount: number,
instanceCount?: number,
firstIndex?: number,
baseVertex?: number,
firstInstance?: number,
) => void;drawIndirect
⚠️ WebGPU only.
Draws primitives using parameters read from a GPUBuffer.
drawIndirect: (indirectBuffer: Buffer, indirectOffset: number) => void;drawIndexedIndirect
⚠️ WebGPU only.
Draws indexed primitives using parameters read from a GPUBuffer.
drawIndexedIndirect: (indirectBuffer: Buffer, indirectOffset: number) => void;beginOcclusionQuery
⚠️ WebGL2 & WebGPU only.
Occlusion query is only available on render passes, to query the number of fragment samples that pass all the per-fragment tests for a set of drawing commands, including scissor, sample mask, alpha to coverage, stencil, and depth tests. Any non-zero result value for the query indicates that at least one sample passed the tests and reached the output merging stage of the render pipeline, 0 indicates that no samples passed the tests.
When beginning a render pass, occlusionQuerySet must be set to be able to use occlusion queries during the pass. An occlusion query is begun and ended by calling beginOcclusionQuery() and endOcclusionQuery() in pairs that cannot be nested.
beginOcclusionQuery: (queryIndex: number) => void;endOcclusionQuery
⚠️ WebGL2 & WebGPU only.
endOcclusionQuery: () => void;ComputePass
⚠️ WebGPU only.
Computing operations provide direct access to GPU’s programmable hardware. Compute shaders do not have shader stage inputs or outputs, their results are side effects from writing data into storage bindings.
dispatchWorkgroups
Dispatch work to be performed with the current ComputePipeline.
X/Y/Z dimension of the grid of workgroups to dispatch.
dispatchWorkgroups: (
workgroupCountX: number,
workgroupCountY?: number,
workgroupCountZ?: number,
) => void;dispatchWorkgroupsIndirect
Dispatch work to be performed with the current GPUComputePipeline using parameters read from a GPUBuffer.
dispatchWorkgroupsIndirect: (
indirectBuffer: Buffer,
indirectOffset: number,
) => void;Program
setUniformsLegacy
⚠️ Only WebGL1 need this method.
setUniformsLegacy: (uniforms: Record<string, any>) => void;program.setUniformsLegacy({
u_ModelViewProjectionMatrix: modelViewProjectionMatrix,
u_Texture: texture,
});Readback
Readback can read data from [Texture](#texture) or [Buffer](#buffer).
readTexture
Read pixels from texture.
- t
requiredTexture. - x
requiredX coordinate. - y
requiredY coordinate. - width
requiredWidth of dimension. - height
requiredHeight of dimension. - dst
requiredDst buffer view. - length
optional
readTexture: (
t: Texture,
x: number,
y: number,
width: number,
height: number,
dst: ArrayBufferView,
dstOffset?: number,
length?: number,
) => Promise<ArrayBufferView>;For instance, if we want to read pixels from a texture:
const texture = device.createTexture({
format: Format.U8_RGBA_NORM,
width: 1,
height: 1,
usage: TextureUsage.SAMPLED,
});
texture.setImageData([new Uint8Array([1, 2, 3, 4])]);
const readback = device.createReadback();
let output = new Uint8Array(4);
// x/y 0/0
await readback.readTexture(texture, 0, 0, 1, 1, output);
expect(output[0]).toBe(1);
expect(output[1]).toBe(2);
expect(output[2]).toBe(3);
expect(output[3]).toBe(4);readTextureSync
⚠️ WebGL1 & WebGL2 only.
readTextureSync: (
t: Texture,
x: number,
y: number,
width: number,
height: number,
dst: ArrayBufferView,
dstOffset?: number,
length?: number,
) => ArrayBufferView;readBuffer
⚠️ WebGL2 & WebGPU only.
Read buffer data.
- src
requiredSource buffer. - srcOffset
optionalOffset in bytes of src buffer. Default to0. - dst
optionalDest buffer view. - dstOffset
optionalOffset in bytes of dst buffer. Default to0. - length
optionalLength in bytes of dst buffer. Default to its whole size.
readBuffer: (
src: Buffer,
srcOffset?: number,
dst?: ArrayBufferView,
dstOffset?: number,
length?: number,
) => Promise<ArrayBufferView>;Shader Language
Since WebGL 1/2 & WebGPU use different shader languages, we do a lot of transpiling work at runtime.
We use a syntax very closed to GLSL 300, and for different devices:
- WebGL1. Downgrade to GLSL 100.
- WebGL2. Almost keep the same which means GLSL 300.
- WebGPU. Transpile to GLSL 440 and then use [gfx-naga]() WASM to generate WGSL.
Syntax as follows:
- [Attribute](#attribute)
- [Varying](#varying)
- [Sampler](#sampler)
- [Uniform](#uniform)
- [gl_Position](#gl_Position)
- [gl_FragColor](#gl_FragColor)
- [Define](#define)
Attribute
// raw
layout(location = 0) in vec4 a_Position;
// compiled GLSL 100
attribute vec4 a_Position;
// compiled GLSL 300
layout(location = 0) in vec4 a_Position;
// compiled GLSL 440
layout(location = 0) in vec4 a_Position;
// compiled WGSL
var<private> a_Position_1: vec4<f32>;
@vertex
fn main(@location(0) a_Position: vec4<f32>) -> VertexOutput {
a_Position_1 = a_Position;
}Varying
// raw
out vec4 a_Position;
// compiled GLSL 100
varying vec4 a_Position;
// compiled GLSL 300
out vec4 a_Position;
// compiled GLSL 440
layout(location = 0) out vec4 a_Position;
// compiled WGSL
struct VertexOutput {
@location(0) v_Position: vec4<f32>,
}Sampler
We need to use SAMPLER_2D / SAMPLER_Cube wrapping our texture.
// raw
uniform sampler2D u_Texture;
outputColor = texture(SAMPLER_2D(u_Texture), v_Uv);
// compiled GLSL 100
uniform sampler2D u_Texture;
outputColor = texture2D(u_Texture, v_TexCoord);
// compiled GLSL 300
uniform sampler2D u_Texture;
outputColor = texture(u_Texture, v_Uv);
// compiled GLSL 440
layout(set = 1, binding = 0) uniform texture2D T_u_Texture;
layout(set = 1, binding = 1) uniform sampler S_u_Texture;
outputColor = texture(sampler2D(T_u_Texture, S_u_Texture), v_Uv);
// compiled WGSL
@group(1) @binding(0)
var T_u_Texture: texture_2d<f32>;
@group(1) @binding(1)
var S_u_Texture: sampler;
outputColor = textureSample(T_u_Texture, S_u_Texture, _e5);Uniform
WebGL2 uses Uniform Buffer Object.
// raw
layout(std140) uniform Uniforms {
mat4 u_ModelViewProjectionMatrix;
};
// compiled GLSL 100
uniform mat4 u_ModelViewProjectionMatrix;
// compiled GLSL 300
layout(std140) uniform Uniforms {
mat4 u_ModelViewProjectionMatrix;
};
// compiled GLSL 440
layout(std140, set = 0, binding = 0) uniform Uniforms {
mat4 u_ModelViewProjectionMatrix;
};
// compiled WGSL
struct Uniforms {
u_ModelViewProjectionMatrix: mat4x4<f32>,
}
@group(0) @binding(0)
var<uniform> global: Uniforms;gl_Position
We still use gl_Position to represent the output of vertex shader:
// raw
gl_Position = vec4(1.0);
// compiled GLSL 100
gl_Position = vec4(1.0);
// compiled GLSL 300
gl_Position = vec4(1.0);
// compiled GLSL 440
gl_Position = vec4(1.0);
// compiled WGSL
struct VertexOutput {
@builtin(position) member: vec4<f32>,
}gl_FragColor
// raw
out vec4 outputColor;
outputColor = vec4(1.0);
// compiled GLSL 100
vec4 outputColor;
outputColor = vec4(1.0);
gl_FragColor = vec4(outputColor);
// compiled GLSL 300
out vec4 outputColor;
outputColor = vec4(1.0);
// compiled GLSL 440
layout(location = 0) out vec4 outputColor;
outputColor = vec4(1.0);
// compiled WGSL
struct FragmentOutput {
@location(0) outputColor: vec4<f32>,
}Define
It is worth mentioning that since WGSL is not natively supported, naga does conditional compilation during the GLSL 440 -> WGSL translation process.
#define KEY VAR
#define PI 3.14