Files
nage/engine/sprites.ts
T
2026-02-19 20:59:10 +01:00

84 lines
1.5 KiB
TypeScript

export type SpritesSheet = {
image: HTMLImageElement;
xFrames: number;
yFrames: number;
frameWidth: number;
frameHeight: number;
};
export type SpriteAnimation = {
sheet: SpritesSheet;
xIndex: number;
yIndex: number;
frameTime: number;
frameDelta: number;
};
export function createSpritesSheet(
image: HTMLImageElement,
xFrames: number,
yFrames: number,
): SpritesSheet {
return {
image,
xFrames,
yFrames,
frameWidth: image.width / xFrames,
frameHeight: image.height / yFrames,
};
}
export function createSpriteAnimation(
sheet: SpritesSheet,
frameTime: number,
yIndex: number,
): SpriteAnimation {
return {
sheet,
xIndex: 0,
yIndex,
frameTime,
frameDelta: 0,
};
}
export function drawSprite(
ctx: CanvasRenderingContext2D,
sheet: SpritesSheet,
xIndex: number,
yIndex: number,
x: number,
y: number,
width?: number,
height?: number,
): void {
ctx.drawImage(
sheet.image,
xIndex * sheet.frameWidth,
yIndex * sheet.frameHeight,
sheet.frameWidth,
sheet.frameHeight,
x,
y,
width || sheet.frameWidth,
height || sheet.frameHeight,
);
}
export function playAnimation(
ctx: CanvasRenderingContext2D,
animation: SpriteAnimation,
x: number,
y: number,
delta: number,
): void {
if ((animation.frameDelta += delta) > animation.frameTime) {
animation.frameDelta = 0;
if ((animation.xIndex += 1) >= animation.sheet.xFrames) {
animation.xIndex = 0;
}
}
drawSprite(ctx, animation.sheet, animation.xIndex, animation.yIndex, x, y);
}