Class: WebglContextManager

WebglContextManager

Handles the webgl context, isolating it from the rest of the DrawerBase API. Manages WebGL context lifecycle, shaders, textures, framebuffers, and other WebGL resources.
Methods

Constructor

new WebglContextManager(options)

Parameters:
Name Type Description
options Object Options for the context manager
Properties
Name Type Attributes Default Description
renderingCanvas HTMLCanvasElement The canvas element to use for WebGL context
unpackWithPremultipliedAlpha Boolean <optional>
 false Whether to enable gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL
imageSmoothingEnabled Boolean <optional>
 true Whether image smoothing is enabled
Source:

Methods

createTexture(data, options) → {WebGLTexture|null}

Create and upload a texture for a tile
Parameters:
Name Type Description
data HTMLImageElement | HTMLCanvasElement | ImageData Image data to upload
options Object Texture options
Properties
Name Type Attributes Description
unpackWithPremultipliedAlpha Boolean <optional>
 Override default unpack setting
Source:
Returns:
The created texture, or null on error
Type
WebGLTexture | null

deleteTexture(texture)

Delete a texture
Parameters:
Name Type Description
texture WebGLTexture The texture to delete
Source:

destroy()

Destroy the WebGL context and all resources
Source:

getContext() → {WebGLRenderingContext|WebGL2RenderingContext|null}

Get the WebGL context
Source:
Returns:
The WebGL context
Type
WebGLRenderingContext | WebGL2RenderingContext | null

getFirstPass() → {Object|null}

Get the first pass shader program and resources
Source:
Returns:
The first pass object with shader program, buffers, and uniforms
Type
Object | null

getFrameBuffer() → {WebGLFramebuffer|null}

Get the render-to-texture framebuffer
Source:
Returns:
The framebuffer
Type
WebGLFramebuffer | null

getMaxTextures() → {Number}

Get the maximum number of texture units
Source:
Returns:
MAX_TEXTURE_IMAGE_UNITS value
Type
Number

getRenderingCanvas() → {HTMLCanvasElement}

Get the rendering canvas element
Source:
Returns:
The canvas element
Type
HTMLCanvasElement

getRenderToTexture() → {WebGLTexture|null}

Get the render-to-texture texture
Source:
Returns:
The texture
Type
WebGLTexture | null

getSecondPass() → {Object|null}

Get the second pass shader program and resources
Source:
Returns:
The second pass object with shader program, buffers, and uniforms
Type
Object | null

getTextureFilter() → {Number}

Get the texture filter constant (LINEAR or NEAREST)
Source:
Returns:
gl.LINEAR or gl.NEAREST
Type
Number

getUnitQuad() → {Float32Array}

Get the unit quad vertex buffer
Source:
Returns:
The unit quad buffer
Type
Float32Array

isDestroyed() → {Boolean}

Check if this context manager has been destroyed
Source:
Returns:
true if destroyed, false otherwise
Type
Boolean

isWebGL2() → {Boolean}

Check if using WebGL2
Source:
Returns:
true if WebGL2, false if WebGL1
Type
Boolean

makeQuadVertexBuffer(left, right, top, bottom) → {Float32Array}

Make a quad vertex buffer
Parameters:
Name Type Description
left Number Left coordinate
right Number Right coordinate
top Number Top coordinate
bottom Number Bottom coordinate
Source:
Returns:
Vertex buffer
Type
Float32Array

resizeRenderer(width, height)

Resize the render-to-texture when canvas size changes
Parameters:
Name Type Description
width Number New canvas width
height Number New canvas height
Source:

setImageSmoothingEnabled(enabled)

Set image smoothing enabled state
Parameters:
Name Type Description
enabled Boolean Whether image smoothing is enabled
Source:

setUnpackWithPremultipliedAlpha(enabled)

Set unpack with premultiplied alpha state
Parameters:
Name Type Description
enabled Boolean Whether to use premultiplied alpha
Source:

setupRenderer(width, height)

Set up the renderer: create shaders, textures, and framebuffers
Parameters:
Name Type Description
width Number Canvas width
height Number Canvas height
Source: