Bezier Curves (The Chickadee Game Toolkit)

From f16fed3d50fd3d56deb46a3d4641a81460e389de Mon Sep 17 00:00:00 2001 From: David Thompson Date: Wed, 12 Dec 2018 09:20:10 -0500 Subject: Update Chickadee manual and home page for 0.3.0. Better late than never! --- manuals/chickadee/Bezier-Curves.html | 174 +++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 manuals/chickadee/Bezier-Curves.html (limited to 'manuals/chickadee/Bezier-Curves.html') diff --git a/manuals/chickadee/Bezier-Curves.html b/manuals/chickadee/Bezier-Curves.html new file mode 100644 index 0000000..6a49b59 --- /dev/null +++ b/manuals/chickadee/Bezier-Curves.html @@ -0,0 +1,174 @@ + + + + + + +Bezier Curves (The Chickadee Game Toolkit) + + + + + + + + + + + + + + + + + + + + + +

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2.2.8 Bezier Curves

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The (chickadee math bezier) module provides an API for +describing cubic Bezier curves in 2D space. These curves are notably +used in font description, vector graphics programs, and when it comes +to games: path building. With Bezier curves, it’s somewhat easy to +create a smooth looking path for an enemy to move along, for example. +Bezier curves become particularly interesting when they are chained +together to form a Bezier “path”, where the end point of one curve +becomes the starting point of the next. +

Currently, the rendering of Bezier curves is rather crude and provided +mostly for visualizing and debugging curves that would be unseen in +the final game. See See Lines and Shapes for more information. +

Procedure: make-bezier-curve p0 p1 p2 p3: Return a new Bezier curve object whose starting point is p0, +ending point is p3, and control points are p1 and +p2. All points are 2D vectors. +

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Procedure: bezier-curve? obj: Return #t if obj is a Bezier curve. +

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Procedure: bezier-curve-p0 bezier: Return the starting point of bezier. +

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Procedure: bezier-curve-p1 bezier: Return the first control point of bezier. +

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Procedure: bezier-curve-p2 bezier: Return the second control point of bezier. +

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Procedure: bezier-curve-p3 bezier: Return the end point of bezier. +

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Procedure: bezier-path . control-points: Return a list of connected bezier curves defined by +control-points. The first curve is defined by the first 4 +arguments and every additional curve thereafter requires 3 additional +arguments. +

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Procedure: bezier-curve-point-at bezier t: Return the coordinates for bezier at t (a value in the +range [0, 1] representing how far from the start of the curve to +check) as a 2D vector. +

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Procedure: bezier-curve-point-at! dest bezier t: Modify the 2D vector dest in-place to contain the coordinates +for bezier at t. +

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