twgl/textures

Gets whether or not we can generate mips for the given format

Gets whether or not we can generate mips for the given
internal format.

Creates a texture based on the options passed in.

Note: may reset UNPACK_ALIGNMENT, UNPACK_ROW_LENGTH, UNPACK_IMAGE_HEIGHT, UNPACK_SKIP_IMAGES
UNPACK_SKIP_PIXELS, and UNPACK_SKIP_ROWS

UNPACK_FLIP_Y_WEBGL, UNPACK_PREMULTIPLY_ALPHA_WEBGL, UNPACK_COLORSPACE_CONVERSION_WEBGL
are left as is though you can pass in options for flipY, premultiplyAlpha, and colorspaceConversion
to override them.

As for the behavior of these settings

gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
t1 = twgl.createTexture({src: someImage }); // flipped
t2 = twgl.createTexture({src: someImage, flipY: true }); // flipped
t3 = twgl.createTexture({src: someImage, flipY: false }); // not flipped
t4 = twgl.createTexture({src: someImage }); // flipped

• t1 is flipped because UNPACK_FLIP_Y_WEBGL is true
• t2 is flipped because it was requested
• t3 is not flipped because it was requested
• t4 is flipped because UNPACK_FLIP_Y_WEBGL has been restored to true

Creates a bunch of textures based on the passed in options.

Example:

const textures = twgl.createTextures(gl, {
  // a power of 2 image
  hftIcon: { src: "images/hft-icon-16.png", mag: gl.NEAREST },
  // a non-power of 2 image
  clover: { src: "images/clover.jpg" },
  // From a canvas
  fromCanvas: { src: ctx.canvas },
  // A cubemap from 6 images
  yokohama: {
    target: gl.TEXTURE_CUBE_MAP,
    src: [
      'images/yokohama/posx.jpg',
      'images/yokohama/negx.jpg',
      'images/yokohama/posy.jpg',
      'images/yokohama/negy.jpg',
      'images/yokohama/posz.jpg',
      'images/yokohama/negz.jpg',
    ],
  },
  // A cubemap from 1 image (can be 1x6, 2x3, 3x2, 6x1)
  goldengate: {
    target: gl.TEXTURE_CUBE_MAP,
    src: 'images/goldengate.jpg',
  },
  // A 2x2 pixel texture from a JavaScript array
  checker: {
    mag: gl.NEAREST,
    min: gl.LINEAR,
    src: [
      255,255,255,255,
      192,192,192,255,
      192,192,192,255,
      255,255,255,255,
    ],
  },
  // a 1x2 pixel texture from a typed array.
  stripe: {
    mag: gl.NEAREST,
    min: gl.LINEAR,
    format: gl.LUMINANCE,
    src: new Uint8Array([
      255,
      128,
      255,
      128,
      255,
      128,
      255,
      128,
    ]),
    width: 1,
  },
});

Now

• textures.hftIcon will be a 2d texture
• textures.clover will be a 2d texture
• textures.fromCanvas will be a 2d texture
• textures.yohohama will be a cubemap texture
• textures.goldengate will be a cubemap texture
• textures.checker will be a 2d texture
• textures.stripe will be a 2d texture

Gets the number of bytes per element for a given internalFormat / type

Gets the format and type for a given internalFormat

Gets the number of components for a given image format.

Loads a texture from an image from a Url as specified in options.src
If options.color !== false will set the texture to a 1x1 pixel color so that the texture is
immediately useable. It will be updated with the contents of the image once the image has finished
downloading. Filtering options will be set as appropriate for image unless options.auto === false.

Resizes a texture based on the options passed in.

Note: This is not a generic resize anything function.
It's mostly used by module:twgl.resizeFramebufferInfo
It will use options.src if it exists to try to determine a type
otherwise it will assume gl.UNSIGNED_BYTE. No data is provided
for the texture. Texture parameters will be set accordingly

Sets the default texture color.

The default texture color is used when loading textures from
urls. Because the URL will be loaded async we'd like to be
able to use the texture immediately. By putting a 1x1 pixel
color in the texture we can start using the texture before
the URL has loaded.

Sets a texture with no contents of a certain size. In other words calls gl.texImage2D with null.
You must set options.width and options.height.

Sets the sampler parameters of a sampler.

Sets filtering or generates mips for texture based on width or height
If width or height is not passed in uses options.width and//or options.height

Sets a texture from an array or typed array. If the width or height is not provided will attempt to
guess the size. See module:twgl.TextureOptions.

Set a texture from the contents of an element. Will also set
texture filtering or generate mips based on the dimensions of the element
unless options.auto === false. If target === gl.TEXTURE_CUBE_MAP will
attempt to slice image into 1x6, 2x3, 3x2, or 6x1 images, one for each face.

Sets the texture parameters of a texture.

Copy the options object and apply pack state

Creates a texture based on the options passed in.

see module:twgl/textures.createTexture.
The only difference is this function returns a promise
where as the other returns a texture and takes a callback.

Note: this is here for completeness. It is probably better to use
the non-async version as it returns a usable texture immediately
where as this one you have to wait for it to load.

Creates textures based on the options passed in.

see module:twgl/textures.createTextures.
The only difference is this function returns a promise
where as the other returns a texture and takes a callback.

Note: this is here for completeness. It is probably better to use
the non-async version as it returns usable textures immediately
where as this one you have to wait for them to load.

returns the property if set or the corresponding state if undefined