Lights (The Chickadee Game Toolkit)

From 0e699be281c8dea53e589e08a5831837e0eae7ea Mon Sep 17 00:00:00 2001 From: David Thompson Date: Thu, 7 Oct 2021 20:17:50 -0400 Subject: Updates for Chickadee 0.8.0 and Guile-SDL2 0.7.0. --- manuals/chickadee/Lights.html | 212 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 212 insertions(+) create mode 100644 manuals/chickadee/Lights.html (limited to 'manuals/chickadee/Lights.html') diff --git a/manuals/chickadee/Lights.html b/manuals/chickadee/Lights.html new file mode 100644 index 0000000..1e6d234 --- /dev/null +++ b/manuals/chickadee/Lights.html @@ -0,0 +1,212 @@ + + + + + + +Lights (The Chickadee Game Toolkit) + + + + + + + + + + + + + + + + + + + + +

5.3.9 Lights

+ +

The (chickadee graphics light) module provides a data type for +dynamic lights that can be used to light 3D objects (such as +Models or Meshes.) +

There are 3 types of dynamic lights: +

point light: +Emits light in all directions from a specific point in space, like a +light bulb. +
directional light: +Emits light of a constant intensity in a direction, like sunlight. +
spot light: +Emits a cone of light in a direction, like a flashlight. +

+ +

Procedure: make-point-light [#:position (vec3 0 0 0)] [#:color black] [#:intensity 1]: +
Return a new point light located at position that emits +color light. +

+ +

Procedure: make-directional-light [#:direction (vec3 0 -1 0)] [#:color black] [#:intensity 1]: +
Return a new directional light that emits color light in +direction. +

+ +

Procedure: make-spot-light [#:position (vec3 0 0 0)] [#:direction (vec3 0 -1 0)] [#:color black] [#:cut-off π/4] [#:intensity 1]: +
Return a new spot light located at position that emits +color light in direction in a cone that cuts off at +cut-off radians. +

+ +

Procedure: point-light? obj: Return #t if obj is a point light. +

+ +

Procedure: directional-light? obj: Return #t if obj is a directional light. +

+ +

Procedure: spot-light? obj: Return #t if obj is a spot light. +

+ +

Procedure: light-type light

Return the type of light, one of: +

point +
directional +
spot +

+ +

Procedure: light-color light: Return the color of light. +

+ +

Procedure: light-intensity light: Return the intensity of light. +

+ +

Procedure: light-position light: Return the position of light. The value is irrelevant for +directional lights. +

+ +

Procedure: light-direction light: Return the direction of light. The value is irrelevant for +point lights. +

+ +

Procedure: light-cut-off light: Return the cosine of the cut off angle of light. The value is +only relevant for spot lights. +

+ +

Procedure: set-light-color! light color: Set the color of light to color. +

+ +

Procedure: set-light-position! light position: Set the position of light to position. +

+ +

Procedure: set-light-direction! light direction: Set the direction of light to direction. +

+ +

Procedure: set-light-cut-off! light cut-off: Set the cut off angle of light to cut-off. +

+ +

+ + + + + + -- cgit v1.2.3