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Function: readPixel()

readPixel(pixelData, x, y, bitsPerChannel): [number, number, number, number]

Defined in: modules/core/src/shadertypes/texture-types/pixel-utils.ts:58

Extracts a single RGBA pixel value from PixelData at the given (x, y) coordinate.

The pixel's data is assumed to be packed according to pixelData.bitsPerChannel. The pixel data for a given row is padded to pixelData.bytesPerRow.

Parameters​

pixelData​

PixelData

The metadata and data for the pixel buffer.

x​

number

The x coordinate (0-based).

y​

number

The y coordinate (0-based).

bitsPerChannel​

[number, number, number, number]

Returns​

[number, number, number, number]

A tuple [r, g, b, a] where each channel is the extracted numeric value.

Example​

Assume you obtained an ArrayBuffer from copyTextureToBuffer and have the following metadata:

 const pixelData: PixelData = {
   bitsPerChannel: [5, 6, 5, 0], // For example, a 16-bit RGB565 format (no alpha)
   width: 800,
   height: 600,
   bytesPerPixel: 2,           // 16 bits per pixel
   bytesPerRow: 1600,          // Assuming no extra padding
   arrayBuffer: myTextureBuffer, // Obtained from copyTextureToBuffer
 };

You can then extract the pixel at (x, y) like so:

 const rgba = extractPixel(pixelData, x, y);
 console.log("Extracted RGBA:", rgba);

For RGBA formats where all channels are present (e.g. [8, 8, 8, 8]), the function will extract a 4-channel pixel value.