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$Graphics

< API

The $Graphics namespace houses graphics utilities for processing images and colors.

Constants

Light direction constants

These constants are common presets to be used as directions for directional lights.

$Graphics.DL_TOP = [ 0.0, 1.0, 1.0 ]            // From the top
$Graphics.DL_LEFT = [ -1.0, 0.0, 1.0 ]          // From the left
$Graphics.DL_RIGHT = [ 1.0, 0.0, 1.0 ]          // From the right
$Graphics.DL_BOTTOM = [ 0.0, -1.0, 1.0 ]        // From the bottom
$Graphics.DL_TL = [ -1.0, 1.0, 1.0 ]            // From the top-left
$Graphics.DL_TR = [ 1.0, 1.0, 1.0 ]             // From the top-right
$Graphics.DL_BL = [ -1.0, -1.0, 1.0 ]           // From the bottom-left
$Graphics.DL_BR = [ 1.0, -1.0, 1.0 ]            // From the bottom-right
$Graphics.DL_DIRECT = [ 0.0, 0.0, 1.0 ]         // Frontlit

Reading material:

Functions

dir_light

$Graphics.dir_light(float luminosity, color c, float[] direction) -> light

Creates and returns a directional light with a luminosity luminosity, a base color c, and a direction specified by the vector direction.

A directional light, as opposed to a point light, shines with a non-dimming luminosity/intensity from a particular direction. It does not originate at any particular position.

Note:

light objects are mutable. Arguments luminosity, c, and direction passed to the constructor can be overridden by using the mutator methods of light.

Reading material:

gen_lookup

$Graphics.gen_lookup(image source, bool dim) -> image

Takes an image source and generates a corresponding lookup image where every non-transparent pixel in source is assigned a unique opaque RGB color. The flag dim determines whether the lookup will have vertical or horizontal striping.

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lerp_color

$Graphics.lerp_color(color a, color b, float t) -> color

Returns the resultant color of a linear interpolation operation performed on colors a and b.

  • If t <= 0.0, returns a
  • If t >= 1.0, returns b
  • Otherwise (0.0 < t < 1.0), returns color specified by a + (Δ * t) where Δ = b - a

lighting

$Graphics.lighting(image texture, image normal, light<> lights) -> image

Sequentially applies a list of lights lights to texture by referencing the surface normal data provided by normal, and returns the lit image.

If texture and normal do not have the same dimensions, returns texture.

point_light

$Graphics.point_light(float luminosity, color c, float radius, int x, int y, float z) -> light

Creates and returns a point light with a source luminosity luminosity, a base color c, a radius radius, a source pixel position specified by x and y, and a relative source Z-axis position specified by z.

A z value of 0.0 means the light is level along the Z-axis with an image being illuminated. A positive z value means the light is in front of an illuminated image, while a negative z value means the light is behind an illuminated image.

A point light, as opposed to a directional light, originates at a specified point and shines from its source position with a linearly dimming luminosity up to a distance specified by its radius.

Note:

light objects are mutable. Arguments luminosity, c, radius, x, y, and z passed to the constructor can be overridden by using the mutator methods of light.

uv_mapping

$Graphics.uv_mapping(image texture, image map, image animation) -> image

Parameters:

  • texture - a color texture
  • map - a lookup map corresponding to the shape and dimensions of texture where every non-transparent pixel should have a unique color
  • animation - a specification for an animation using the colors in map

Returns:

If texture and map do not have the same dimensions, returns animation.

Otherwise, returns the following image:

  • Initializes a blank image with the same dimensions as animation
  • For every non-transparent pixel at position (ax, ay) in animation...
    • checks if the color c sampled at that pixel is present in map
    • If it is...
      • assigns the first (and ideally only) pixel instance of c as (mx, my)
      • sets position (ax, ay) of the output image to the color of the pixel at (mx, my) in texture
    • If it isn't...
      • sets position (ax, ay) of the output image to c

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