WebglGraphicsDevice
Extends: GraphicsDevice
The graphics device manages the underlying graphics context. It is responsible for submitting render state changes and graphics primitives to the hardware. A graphics device is tied to a specific canvas HTML element. It is valid to have more than one canvas element per page and create a new graphics device against each.
Summary
Properties
fullscreen | Fullscreen mode. |
height | Height of the back buffer in pixels. |
textureFloatHighPrecision | Check if high precision floating-point textures are supported. |
textureHalfFloatUpdatable | Check if texture with half float format can be updated with data. |
width | Width of the back buffer in pixels. |
Methods
clear | Clears the frame buffer of the currently set render target. |
copyRenderTarget | Copies source render target into destination render target. |
destroy | Destroy the graphics device. |
draw | Submits a graphical primitive to the hardware for immediate rendering. |
setScissor | Set the active scissor rectangle on the specified device. |
setShader | Sets the active shader to be used during subsequent draw calls. |
setViewport | Set the active rectangle for rendering on the specified device. |
Inherited
Properties
boneLimit | The maximum number of supported bones using uniform buffers.[read only] |
canvas | The canvas DOM element that provides the underlying WebGL context used by the graphics device.[read only] |
deviceType | The type of the device. |
fullscreen | Fullscreen mode. |
gpuProfiler | The GPU profiler. |
height | Height of the back buffer in pixels. |
insideRenderPass | |
isWebGPU | True if the deviceType is WebGPU [read only] |
maxAnisotropy | The maximum supported texture anisotropy setting.[read only] |
maxColorAttachments | The maximum supported number of color buffers attached to a render target.[read only] |
maxCubeMapSize | The maximum supported dimension of a cube map.[read only] |
maxPixelRatio | Maximum pixel ratio. |
maxTextureSize | The maximum supported dimension of a texture.[read only] |
maxVolumeSize | The maximum supported dimension of a 3D texture (any axis).[read only] |
precision | The highest shader precision supported by this graphics device.[read only] |
samples | The number of hardware anti-aliasing samples used by the frame buffer.[read only] |
scope | The scope namespace for shader attributes and variables.[read only] |
shaders | |
supportsInstancing | True if hardware instancing is supported.[read only] |
supportsMrt | True if Multiple Render Targets feature is supported.[read only] |
supportsVolumeTextures | True if the device supports volume textures.[read only] |
targets | |
textureFloatRenderable | True if 32-bit floating-point textures can be used as a frame buffer.[read only] |
textureHalfFloatRenderable | True if 16-bit floating-point textures can be used as a frame buffer.[read only] |
textures | |
width | Width of the back buffer in pixels. |
Methods
fire | Fire an event, all additional arguments are passed on to the event listener. |
getRenderTarget | Queries the currently set render target on the device. |
hasEvent | Test if there are any handlers bound to an event name. |
off | Detach an event handler from an event. |
on | Attach an event handler to an event. |
once | Attach an event handler to an event. |
postInit | Function that executes after the device has been created. |
setBlendState | Sets the specified blend state. |
setCullMode | Controls how triangles are culled based on their face direction. |
setDepthState | Sets the specified depth state. |
setIndexBuffer | Sets the current index buffer on the graphics device. |
setRenderTarget | Sets the specified render target on the device. |
setStencilState | Sets the specified stencil state. |
setVertexBuffer | Sets the current vertex buffer on the graphics device. |
Events
resizecanvas | Fired when the canvas is resized. |
Details
Constructor
WebglGraphicsDevice(canvas, [options])
Creates a new WebglGraphicsDevice instance.
Parameters
canvas | HTMLCanvasElement | The canvas to which the graphics device will render. |
options | object | Options passed when creating the WebGL context. |
options.alpha | boolean | Boolean that indicates if the canvas contains an alpha buffer. |
options.depth | boolean | Boolean that indicates that the drawing buffer is requested to have a depth buffer of at least 16 bits. |
options.stencil | boolean | Boolean that indicates that the drawing buffer is requested to have a stencil buffer of at least 8 bits. |
options.antialias | boolean | Boolean that indicates whether or not to perform anti-aliasing if possible. |
options.premultipliedAlpha | boolean | Boolean that indicates that the page compositor will assume the drawing buffer contains colors with pre-multiplied alpha. |
options.preserveDrawingBuffer | boolean | If the value is true the buffers will not be cleared and will preserve their values until cleared or overwritten by the author. |
options.powerPreference | 'default', 'high-performance', 'low-power' | A hint to the user agent indicating what configuration of GPU is suitable for the WebGL context. Possible values are:
|
options.failIfMajorPerformanceCaveat | boolean | Boolean that indicates if a context will be created if the system performance is low or if no hardware GPU is available. |
options.preferWebGl2 | boolean | Boolean that indicates if a WebGl2 context should be preferred. |
options.desynchronized | boolean | Boolean that hints the user agent to reduce the latency by desynchronizing the canvas paint cycle from the event loop. |
options.xrCompatible | boolean | Boolean that hints to the user agent to use a compatible graphics adapter for an immersive XR device. |
options.gl | WebGLRenderingContext, WebGL2RenderingContext | The rendering context to use. If not specified, a new context will be created. |
Properties
Check if texture with half float format can be updated with data.
Methods
clear([options])
Clears the frame buffer of the currently set render target.
// Clear color buffer to black and depth buffer to 1.0
device.clear();
// Clear just the color buffer to red
device.clear({
color: [1, 0, 0, 1],
flags: pc.CLEARFLAG_COLOR
});
// Clear color buffer to yellow and depth to 1.0
device.clear({
color: [1, 1, 0, 1],
depth: 1,
flags: pc.CLEARFLAG_COLOR | pc.CLEARFLAG_DEPTH
});
Parameters
options | object | Optional options object that controls the behavior of the clear operation defined as follows: |
options.color | number[] | The color to clear the color buffer to in the range 0.0 to 1.0 for each component. |
options.depth | number | The depth value to clear the depth buffer to in the range 0.0 to 1.0. |
options.flags | number | The buffers to clear (the types being color, depth and stencil). Can be any bitwise combination of: |
options.stencil | number | The stencil value to clear the stencil buffer to. Defaults to 0. |
copyRenderTarget([source], [dest], [color], [depth])
Copies source render target into destination render target. Mostly used by post-effects.
Parameters
source | RenderTarget | The source render target. Defaults to frame buffer. |
dest | RenderTarget | The destination render target. Defaults to frame buffer. |
color | boolean | If true will copy the color buffer. Defaults to false. |
depth | boolean | If true will copy the depth buffer. Defaults to false. |
Returns
booleanTrue if the copy was successful, false otherwise.
destroy()
Destroy the graphics device.
draw(primitive, [numInstances], [keepBuffers])
Submits a graphical primitive to the hardware for immediate rendering.
// Render a single, unindexed triangle
device.draw({
type: pc.PRIMITIVE_TRIANGLES,
base: 0,
count: 3,
indexed: false
});
Parameters
primitive | object | Primitive object describing how to submit current vertex/index buffers. |
primitive.type | number | The type of primitive to render. Can be: |
primitive.base | number | The offset of the first index or vertex to dispatch in the draw call. |
primitive.count | number | The number of indices or vertices to dispatch in the draw call. |
primitive.indexed | boolean | True to interpret the primitive as indexed, thereby using the currently set index buffer and false otherwise. |
numInstances | number | The number of instances to render when using ANGLE_instanced_arrays. Defaults to 1. |
keepBuffers | boolean | Optionally keep the current set of vertex / index buffers / VAO. This is used when rendering of multiple views, for example under WebXR. |
setScissor(x, y, w, h)
Set the active scissor rectangle on the specified device.
Parameters
x | number | The pixel space x-coordinate of the bottom left corner of the scissor rectangle. |
y | number | The pixel space y-coordinate of the bottom left corner of the scissor rectangle. |
w | number | The width of the scissor rectangle in pixels. |
h | number | The height of the scissor rectangle in pixels. |
setShader(shader)
Sets the active shader to be used during subsequent draw calls.
Parameters
shader | Shader | The shader to set to assign to the device. |
Returns
booleanTrue if the shader was successfully set, false otherwise.
setViewport(x, y, w, h)
Set the active rectangle for rendering on the specified device.
Parameters
x | number | The pixel space x-coordinate of the bottom left corner of the viewport. |
y | number | The pixel space y-coordinate of the bottom left corner of the viewport. |
w | number | The width of the viewport in pixels. |
h | number | The height of the viewport in pixels. |
Inherited
Properties
The canvas DOM element that provides the underlying WebGL context used by the graphics device.
[read only]The type of the device. Can be one of pc.DEVICETYPE_WEBGL1, pc.DEVICETYPE_WEBGL2 or pc.DEVICETYPE_WEBGPU.
The maximum supported number of color buffers attached to a render target.
[read only]The highest shader precision supported by this graphics device. Can be 'hiphp', 'mediump' or 'lowp'.
[read only]True if Multiple Render Targets feature is supported. This refers to the ability to render to multiple color textures with a single draw call.
[read only]True if 32-bit floating-point textures can be used as a frame buffer.
[read only]True if 16-bit floating-point textures can be used as a frame buffer.
[read only]Methods
fire(name, [arg1], [arg2], [arg3], [arg4], [arg5], [arg6], [arg7], [arg8])
Fire an event, all additional arguments are passed on to the event listener.
obj.fire('test', 'This is the message');
Parameters
name | string | Name of event to fire. |
arg1 | * | First argument that is passed to the event handler. |
arg2 | * | Second argument that is passed to the event handler. |
arg3 | * | Third argument that is passed to the event handler. |
arg4 | * | Fourth argument that is passed to the event handler. |
arg5 | * | Fifth argument that is passed to the event handler. |
arg6 | * | Sixth argument that is passed to the event handler. |
arg7 | * | Seventh argument that is passed to the event handler. |
arg8 | * | Eighth argument that is passed to the event handler. |
Returns
EventHandlerSelf for chaining.
getRenderTarget()
Queries the currently set render target on the device.
// Get the current render target
const renderTarget = device.getRenderTarget();
Returns
RenderTargetThe current render target.
hasEvent(name)
Test if there are any handlers bound to an event name.
obj.on('test', function () { }); // bind an event to 'test'
obj.hasEvent('test'); // returns true
obj.hasEvent('hello'); // returns false
Parameters
name | string | The name of the event to test. |
Returns
booleanTrue if the object has handlers bound to the specified event name.
off([name], [callback], [scope])
Detach an event handler from an event. If callback is not provided then all callbacks are unbound from the event, if scope is not provided then all events with the callback will be unbound.
const handler = function () {
};
obj.on('test', handler);
obj.off(); // Removes all events
obj.off('test'); // Removes all events called 'test'
obj.off('test', handler); // Removes all handler functions, called 'test'
obj.off('test', handler, this); // Removes all handler functions, called 'test' with scope this
Parameters
name | string | Name of the event to unbind. |
callback | HandleEventCallback | Function to be unbound. |
scope | object | Scope that was used as the this when the event is fired. |
Returns
EventHandlerSelf for chaining.
on(name, callback, [scope])
Attach an event handler to an event.
obj.on('test', function (a, b) {
console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
Parameters
name | string | Name of the event to bind the callback to. |
callback | HandleEventCallback | Function that is called when event is fired. Note the callback is limited to 8 arguments. |
scope | object | Object to use as 'this' when the event is fired, defaults to current this. |
Returns
EventHandlerSelf for chaining.
once(name, callback, [scope])
Attach an event handler to an event. This handler will be removed after being fired once.
obj.once('test', function (a, b) {
console.log(a + b);
});
obj.fire('test', 1, 2); // prints 3 to the console
obj.fire('test', 1, 2); // not going to get handled
Parameters
name | string | Name of the event to bind the callback to. |
callback | HandleEventCallback | Function that is called when event is fired. Note the callback is limited to 8 arguments. |
scope | object | Object to use as 'this' when the event is fired, defaults to current this. |
Returns
EventHandlerSelf for chaining.
postInit()
Function that executes after the device has been created.
setBlendState(blendState)
Sets the specified blend state.
Parameters
blendState | BlendState | New blend state. |
setCullMode(cullMode)
Controls how triangles are culled based on their face direction. The default cull mode is CULLFACE_BACK.
Parameters
cullMode | number | The cull mode to set. Can be: |
setDepthState(depthState)
Sets the specified depth state.
Parameters
depthState | DepthState | New depth state. |
setIndexBuffer(indexBuffer)
Sets the current index buffer on the graphics device. On subsequent calls to GraphicsDevice#draw, the specified index buffer will be used to provide index data for any indexed primitives.
Parameters
indexBuffer | IndexBuffer | The index buffer to assign to the device. |
setRenderTarget(renderTarget)
Sets the specified render target on the device. If null is passed as a parameter, the back buffer becomes the current target for all rendering operations.
// Set a render target to receive all rendering output
device.setRenderTarget(renderTarget);
// Set the back buffer to receive all rendering output
device.setRenderTarget(null);
Parameters
renderTarget | RenderTarget | The render target to activate. |
setStencilState([stencilFront], [stencilBack])
Sets the specified stencil state. If both stencilFront and stencilBack are null, stencil operation is disabled.
Parameters
stencilFront | StencilParameters | The front stencil parameters. Defaults to StencilParameters.DEFAULT if not specified. |
stencilBack | StencilParameters | The back stencil parameters. Defaults to StencilParameters.DEFAULT if not specified. |
setVertexBuffer(vertexBuffer)
Sets the current vertex buffer on the graphics device. On subsequent calls to GraphicsDevice#draw, the specified vertex buffer(s) will be used to provide vertex data for any primitives.
Parameters
vertexBuffer | VertexBuffer | The vertex buffer to assign to the device. |