mirror of
https://github.com/bspeice/speice.io
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41 lines
897 B
TypeScript
41 lines
897 B
TypeScript
export function camera(
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x: number,
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y: number,
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width: number,
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height: number,
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positionX: number,
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positionY: number,
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rotate: number,
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zoom: number,
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scale: number,
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): [number, number] {
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// Position, rotation, and zoom are
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// applied in IFS coordinates
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[x, y] = [
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(x - positionX),
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(y - positionY),
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];
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[x, y] = [
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x * Math.cos(rotate) -
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y * Math.sin(rotate),
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x * Math.sin(rotate) +
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y * Math.cos(rotate),
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];
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[x, y] = [
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x * Math.pow(2, zoom),
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y * Math.pow(2, zoom)
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];
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// Scale transforms IFS coordinates
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// to pixel coordinates. Shift by half
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// the image width and height
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// to compensate for IFS coordinates
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// being symmetric around the origin
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return [
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Math.floor(x * scale + width / 2),
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Math.floor(y * scale + height / 2)
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];
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}
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