Class Image

Class Documentation

class Image

Manages the state of an image.

Public Functions

Image()
void update_from(const Image &other)

Updates this image’s state with the state of other, accounting for prior changes to this objects’s state.

Parameters:

other[in] the object to update the state from.

void clear()

Clear dirty flags.

Resets any changes since the last call to PointViz::update()

void dirty()

Set all dirty flags.

Re-sets everything so the object is always redrawn.

void set_image(size_t width, size_t height, const float *image_data)

Set the image data.

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data[in] pointer to an array of width * height elements interpreted as a row-major monochrome image

void set_image(size_t width, size_t height, const uint8_t *image_data)

Set the image data.

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data[in] pointer to an array of width * height elements interpreted as a row-major monochrome image

void set_image_rgb(size_t width, size_t height, const float *image_data_rgb)

Set the image data (RGB).

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data_rgb[in] pointer to an array of width * height elements interpreted as a row-major RGB image

void set_image_rgb(size_t width, size_t height, const uint8_t *image_data_rgb)

Set the image data (RGB).

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data_rgb[in] pointer to an array of width * height elements interpreted as a row-major RGB image

void set_image_rgba(size_t width, size_t height, const float *image_data_rgba)

Set the image data (RGBA).

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data_rgba[in] pointer to an array of width * height elements interpreted as a row-major RGBA image

void set_image_rgba(size_t width, size_t height, const uint8_t *image_data_rgba)

Set the image data (RGBA).

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • image_data_rgba[in] pointer to an array of width * height elements interpreted as a row-major RGBA image

void set_mask(size_t width, size_t height, const float *mask_data)

Set the RGBA mask.

Not required to be the same resolution as the image data

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • mask_data[in] pointer to array of 4 * width * height elements interpreted as a row-major rgba image

void set_mask(size_t width, size_t height, const uint8_t *mask_data)

Set the RGBA mask.

Not required to be the same resolution as the image data

Parameters:

  • width[in] width of the image data in pixels

  • height[in] height of the image data in pixels

  • mask_data[in] pointer to array of 4 * width * height elements interpreted as a row-major rgba image

void set_position(float x_min, float x_max, float y_min, float y_max)

Set the display position of the image.

Parameters:

  • x_min[in]

  • x_max[in]

  • y_min[in]

  • y_max –

void set_hshift(float hshift)

Set horizontal shift in normalized viewport screen width coordinate.

This may be used to “snap” images to the left/right screen edges.

Some example values: 0 - default, image is centered horizontally on the screen -0.5 - image moved to the left for the 1/4 of a horizontal viewport -1 - image moved to the left for the 1/2 of a horizontal viewport +1 - image moved to the right for the 1/2 of a horizontal viewport +0.5 - image moved to the right for the 1/4 of a horizontal viewport

Parameters:

hshift[in] shift in normalized by width coordinates from 0 at the center [-1.0..1.0]

void set_palette(const float *palette, size_t palette_size)

Set the image color palette.

Parameters:

  • palette[in] the new palette to use, must have size 3*palette_size

  • palette_size[in] the number of colors in the new palette

void clear_palette()

Removes the image color palette.

std::pair<int, int> viewport_coordinates_to_image_pixel(const WindowCtx &ctx, double x, double y) const

Returns the image pixel corresponding to the provided viewport coordinates.

Parameters:

  • ctx[in] the WindowCtx.

  • x[in] X coordinate for the viewport

  • y[in] Y coordinate for the viewport

Throws:

std::runtime_error – if the image data has not been set, or if the image size (set by set_position) is zero in either dimension.

Returns:

Image pixel corresponding to the provided viewport coordinates. IMPORTANT: the pixel is outside the image if either the (x, y) are less than zero or greater than the image (width, height).

std::pair<double, double> image_pixel_to_viewport_coordinates(const WindowCtx &ctx, int px, int py) const

Returns the inverse of “viewport_coordinates_to_image_pixel” This is useful for computing positions relative to an image pixel.

Parameters:

  • ctx[in] the WindowCtx.

  • px[in] X pixel coordinate

  • py[in] Y pixel coordinate

Returns:

a coordinate normalized to -1, 1 in the window’s Y axis

std::pair<double, double> pixel_size(const WindowCtx &ctx) const

Returns the pixel size as a pair representing width and height in window pixels.

Parameters:

ctx[in] the WindowCtx.

Returns:

a pair representing the image pixel size in window pixels.

Friends

friend class impl::GLImage
friend class PointViz