WebGLRenderingContext.texSubImage2D

The WebGLRenderingContext.texSubImage2D() method of the WebGL API specifies a sub-rectangle of the current texture.

Syntax

// WebGL 1:
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, ArrayBufferView? pixels);
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, ImageData? pixels);
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, HTMLImageElement? pixels);
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, HTMLCanvasElement? pixels);
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, HTMLVideoElement? pixels);
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, ImageBitmap? pixels);

// WebGL 2:
void gl.texSubImage2D(target, level, xoffset, yoffset, format, type, GLintptr offset);
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, HTMLCanvasElement source);
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, HTMLImageElement source);
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, HTMLVideoElement source); 
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, ImageBitmap source); 
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, ImageData source);
void gl.texSubImage2D(target, level, xoffset, yoffset, width, height, format, type, ArrayBufferView srcData, srcOffset);

Parameters

target

A GLenum specifying the binding point (target) of the active texture. Possible values:

• gl.TEXTURE_2D: A two-dimensional texture.
• gl.TEXTURE_CUBE_MAP_POSITIVE_X: Positive X face for a cube-mapped texture.
• gl.TEXTURE_CUBE_MAP_NEGATIVE_X: Negative X face for a cube-mapped texture.
• gl.TEXTURE_CUBE_MAP_POSITIVE_Y: Positive Y face for a cube-mapped texture.
• gl.TEXTURE_CUBE_MAP_NEGATIVE_Y: Negative Y face for a cube-mapped texture.
• gl.TEXTURE_CUBE_MAP_POSITIVE_Z: Positive Z face for a cube-mapped texture.
• gl.TEXTURE_CUBE_MAP_NEGATIVE_Z: Negative Z face for a cube-mapped texture.

level

A GLint specifying the level of detail. Level 0 is the base image level and level n is the nth mipmap reduction level.

xoffset

A GLint specifying the horizontal offset within the texture image.

yoffset

A GLint specifying the vertical offset within the texture image.

width

A GLsizei specifying the width of the texture.

height

A GLsizei specifying the height of the texture.

format

A GLenum specifying the format of the texel data. Possible values:

• gl.ALPHA: Discards the red, green and blue components and reads the alpha component.
• gl.RGB: Discards the alpha components and reads the red, green and blue components.
• gl.RGBA: Red, green, blue and alpha components are read from the color buffer.
• gl.LUMINANCE: Each color component is a luminance component, alpha is 1.0.
• gl.LUMINANCE_ALPHA: Each component is a luminance/alpha component.
• When using the EXT_sRGB extension:
  • ext.SRGB_EXT
  • ext.SRGB_ALPHA_EXT
• When using a WebGL 2 context, the following values are available additionally:
  • gl.R8
  • gl.R16F
  • gl.R32F
  • gl.R8UI
  • gl.RG8
  • gl.RG16F
  • gl.RG32F
  • gl.RGUI
  • gl.RGB8
  • gl.SRGB8
  • gl.RGB565
  • gl.R11F_G11F_B10F
  • gl.RGB9_E5
  • gl.RGB16F
  • gl.RGB32F
  • gl.RGB8UI
  • gl.RGBA8
  • gl.SRGB_APLHA8
  • gl.RGB5_A1
  • gl.RGBA4444
  • gl.RGBA16F
  • gl.RGBA32F
  • gl.RGBA8UI

type

A GLenum specifying the data type of the texel data. Possible values:

• gl.UNSIGNED_BYTE: 8 bits per channel for gl.RGBA
• gl.UNSIGNED_SHORT_5_6_5: 5 red bits, 6 green bits, 5 blue bits.
• gl.UNSIGNED_SHORT_4_4_4_4: 4 red bits, 4 green bits, 4 blue bits, 4 alpha bits.
• gl.UNSIGNED_SHORT_5_5_5_1: 5 red bits, 5 green bits, 5 blue bits, 1 alpha bit.
• When using the OES_texture_float extension:
  • gl.FLOAT
• When using the OES_texture_half_float extension:
  • gl.HALF_FLOAT_OES
• When using a WebGL 2 context, the following values are available additionally:
  • gl.BYTE
  • gl.UNSIGNED_SHORT
  • gl.SHORT
  • gl.UNSIGNED_INT
  • gl.INT
  • gl.HALF_FLOAT
  • gl.FLOAT
  • gl.UNSIGNED_INT_2_10_10_10_REV
  • gl.UNSIGNED_INT_10F_11F_11F_REV
  • gl.UNSIGNED_INT_5_9_9_9_REV
  • gl.UNSIGNED_INT_24_8
  • gl.FLOAT_32_UNSIGNED_INT_24_8_REV (pixels must be null)

pixels

One of the following objects can be used as a pixel source for the texture:

• ArrayBufferView,
  • A Uint8Array must be used if type is gl.UNSIGNED_BYTE.
  • A Uint16Array must be used if type is either gl.UNSIGNED_SHORT_5_6_5, gl.UNSIGNED_SHORT_4_4_4_4, gl.UNSIGNED_SHORT_5_5_5_1, or ext.HALF_FLOAT_OES.
  • A Float32Array must be used if type is gl.FLOAT.
• ImageData,
• HTMLImageElement,
• HTMLCanvasElement,
• HTMLVideoElement,
• ImageBitmap.

offset

(WebGL 2 only) A GLintptr byte offset into the WebGLBuffer's data store. Used to upload data to the currently bound WebGLTexture from the WebGLBuffer bound to the PIXEL_UNPACK_BUFFER target.

Return value

None.

Examples

gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, gl.RGBA, gl.UNSIGNED_BYTE, image);

Specifications

Specification	Status	Comment
WebGL 1.0 The definition of 'texSubImage2D' in that specification.	Recommendation	Initial definition for WebGL.
OpenGL ES 2.0 The definition of 'glTexSubImage2D' in that specification.	Standard	Man page of the (similar) OpenGL ES 2.0 API.
WebGL 2.0 The definition of 'texSubImage2D' in that specification.	Editor's Draft	Updated definition for WebGL.
OpenGL ES 3.0 The definition of 'glTexSubImage2D' in that specification.	Standard	Man page of the (similar) OpenGL ES 3.0 API.

Browser compatibility

See also

• WebGLRenderingContext.createTexture()
• WebGLRenderingContext.bindTexture()
• WebGLRenderingContext.texImage2D()
• WebGLRenderingContext.compressedTexImage2D()
• WebGLRenderingContext.copyTexImage2D()
• WebGLRenderingContext.getTexParameter()
• OES_texture_float
• OES_texture_half_float
• EXT_sRGB