js-draw
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Draw pictures using a pen, touchscreen, or mouse! JS-draw is a drawing library for JavaScript and TypeScript.
60 lines (59 loc) • 2.22 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const math_1 = require("@js-draw/math");
// Represents a cached renderer/canvas
// This is not a [CacheNode] -- it handles cached renderers and does not have sub-renderers.
class CacheRecord {
constructor(onBeforeDeallocCallback, cacheState) {
this.onBeforeDeallocCallback = onBeforeDeallocCallback;
this.cacheState = cacheState;
this.allocd = false;
// For debugging
this.allocCount = 0;
this.renderer = cacheState.props.createRenderer();
this.lastUsedCycle = -1;
this.allocd = true;
}
startRender() {
this.lastUsedCycle = this.cacheState.currentRenderingCycle;
if (!this.allocd) {
throw new Error("Only alloc'd canvases can be rendered to");
}
return this.renderer;
}
dealloc() {
this.onBeforeDeallocCallback?.();
this.allocd = false;
this.onBeforeDeallocCallback = null;
this.lastUsedCycle = 0;
}
isAllocd() {
return this.allocd;
}
realloc(newDeallocCallback) {
if (this.allocd) {
this.dealloc();
}
this.allocd = true;
this.onBeforeDeallocCallback = newDeallocCallback;
this.lastUsedCycle = this.cacheState.currentRenderingCycle;
this.allocCount++;
}
getLastUsedCycle() {
return this.lastUsedCycle;
}
// Returns the transformation that maps [drawTo] to this' renderable region
// (i.e. a [cacheProps.blockResolution]-sized rectangle with top left at (0, 0))
getTransform(drawTo) {
const transform = math_1.Mat33.scaling2D(this.cacheState.props.blockResolution.x / drawTo.size.x).rightMul(math_1.Mat33.translation(drawTo.topLeft.times(-1)));
return transform;
}
setRenderingRegion(drawTo) {
const transform = this.getTransform(drawTo);
this.renderer.setTransform(transform);
// The visible region may be slightly larger than where we're actually drawing
// to (because of rounding).
this.renderer.overrideVisibleRect(drawTo.grownBy(1 / transform.getScaleFactor()));
}
}
exports.default = CacheRecord;