ImageSensorWrapper

public class ImageSensorWrapper : TransformNodeWrapper

Component-logic handle on an ImageSensor marker, exposed as Rendering.<Name>. A transform node (it can be aimed and moved like any pivot) that can photograph what is in front of it: Capture asks the host for a frame, and once FrameVersion has moved the pixel readers answer from it. The frame is the marker’s Width x Height, RGB, row-major, top row first, exactly as a camera module delivers it.

Agnostic: a line follower reads Luminance(x, 0) across one row, a reflectance sensor reads MeanLuminance of a tiny frame, a colour sensor reads Pixel, a camera module copies the whole thing out. Every reader is bounds-safe and never throws: out of range reads are black, and before the first frame everything reads zero.

Timing: call Capture from Update at whatever rate the device frames (real modules run at tens of frames per second, not the physics rate); the frame arrives one render frame later. Readers are safe from either logic entry point.

Properties you read and set

Width

public int Width { get; }

Width of the frame in pixels (the marker’s authored width until a frame arrives).

Height

public int Height { get; }

Height of the frame in pixels (the marker’s authored height until a frame arrives).

FrameVersion

public int FrameVersion { get; }

Counts published frames. Compare against the value you last processed so a frame is read once, not once per Update.

HasFrame

public bool HasFrame { get; }

True once at least one frame has been delivered.

Methods you call

Capture

public void Capture();

Ask for a frame. Rendered at the next draw and readable one frame later; asking again before it arrives is harmless (one frame is in flight at a time).

Luminance

public double Luminance(int x, int y);

Relative luminance 0..1 of one pixel (x right, y down). Out of range or no frame = 0.

Pixel

public Color Pixel(int x, int y);

One pixel’s colour (components 0..1, alpha 1). Out of range or no frame = black.

MeanLuminance

public double MeanLuminance();

Mean relative luminance 0..1 of the whole frame - the single number a reflectance sensor or a light-level camera reduces to.

public double MeanLuminance(int x0, int y0, int x1, int y1);

Mean relative luminance of the rectangle [x0, x1) x [y0, y1), clamped to the frame - one cell of an optical array, one side of a line sensor.

CopyPixels

public int CopyPixels(byte[] rgb);

Copy the frame (RGB8, row-major, top row first) into rgb. Returns the number of bytes written (0 when there is no frame or the buffer is too small: it needs Width x Height x 3).

Generated from the CRUMB source, commit fcec660d, 2026-10-29.