Source: \core\graphics\canvas\CanvasGraphicsRenderer.js
import CanvasRenderer from '../../renderers/canvas/CanvasRenderer';
import { SHAPES } from '../../const';
/**
* @author Mat Groves
*
* Big thanks to the very clever Matt DesLauriers https://github.com/mattdesl/
* for creating the original pixi version!
* Also a thanks to https://github.com/bchevalier for tweaking the tint and alpha so that they
* now share 4 bytes on the vertex buffer
*
* Heavily inspired by LibGDX's CanvasGraphicsRenderer:
* https://github.com/libgdx/libgdx/blob/1.0.0/gdx/src/com/badlogic/gdx/graphics/glutils/ShapeRenderer.java
*/
/**
* Renderer dedicated to drawing and batching graphics objects.
*
* @class
* @private
* @memberof PIXI
*/
export default class CanvasGraphicsRenderer
{
/**
* @param {PIXI.CanvasRenderer} renderer - The current PIXI renderer.
*/
constructor(renderer)
{
this.renderer = renderer;
}
/**
* Renders a Graphics object to a canvas.
*
* @param {PIXI.Graphics} graphics - the actual graphics object to render
*/
render(graphics)
{
const renderer = this.renderer;
const context = renderer.context;
const worldAlpha = graphics.worldAlpha;
const transform = graphics.transform.worldTransform;
const resolution = renderer.resolution;
// if the tint has changed, set the graphics object to dirty.
if (this._prevTint !== this.tint)
{
this.dirty = true;
}
context.setTransform(
transform.a * resolution,
transform.b * resolution,
transform.c * resolution,
transform.d * resolution,
transform.tx * resolution,
transform.ty * resolution
);
if (graphics.dirty)
{
this.updateGraphicsTint(graphics);
graphics.dirty = false;
}
renderer.setBlendMode(graphics.blendMode);
for (let i = 0; i < graphics.graphicsData.length; i++)
{
const data = graphics.graphicsData[i];
const shape = data.shape;
const fillColor = data._fillTint;
const lineColor = data._lineTint;
context.lineWidth = data.lineWidth;
if (data.type === SHAPES.POLY)
{
context.beginPath();
this.renderPolygon(shape.points, shape.closed, context);
for (let j = 0; j < data.holes.length; j++)
{
this.renderPolygon(data.holes[j].points, true, context);
}
if (data.fill)
{
context.globalAlpha = data.fillAlpha * worldAlpha;
context.fillStyle = `#${(`00000${(fillColor | 0).toString(16)}`).substr(-6)}`;
context.fill();
}
if (data.lineWidth)
{
context.globalAlpha = data.lineAlpha * worldAlpha;
context.strokeStyle = `#${(`00000${(lineColor | 0).toString(16)}`).substr(-6)}`;
context.stroke();
}
}
else if (data.type === SHAPES.RECT)
{
if (data.fillColor || data.fillColor === 0)
{
context.globalAlpha = data.fillAlpha * worldAlpha;
context.fillStyle = `#${(`00000${(fillColor | 0).toString(16)}`).substr(-6)}`;
context.fillRect(shape.x, shape.y, shape.width, shape.height);
}
if (data.lineWidth)
{
context.globalAlpha = data.lineAlpha * worldAlpha;
context.strokeStyle = `#${(`00000${(lineColor | 0).toString(16)}`).substr(-6)}`;
context.strokeRect(shape.x, shape.y, shape.width, shape.height);
}
}
else if (data.type === SHAPES.CIRC)
{
// TODO - need to be Undefined!
context.beginPath();
context.arc(shape.x, shape.y, shape.radius, 0, 2 * Math.PI);
context.closePath();
if (data.fill)
{
context.globalAlpha = data.fillAlpha * worldAlpha;
context.fillStyle = `#${(`00000${(fillColor | 0).toString(16)}`).substr(-6)}`;
context.fill();
}
if (data.lineWidth)
{
context.globalAlpha = data.lineAlpha * worldAlpha;
context.strokeStyle = `#${(`00000${(lineColor | 0).toString(16)}`).substr(-6)}`;
context.stroke();
}
}
else if (data.type === SHAPES.ELIP)
{
// ellipse code taken from: http://stackoverflow.com/questions/2172798/how-to-draw-an-oval-in-html5-canvas
const w = shape.width * 2;
const h = shape.height * 2;
const x = shape.x - (w / 2);
const y = shape.y - (h / 2);
context.beginPath();
const kappa = 0.5522848;
const ox = (w / 2) * kappa; // control point offset horizontal
const oy = (h / 2) * kappa; // control point offset vertical
const xe = x + w; // x-end
const ye = y + h; // y-end
const xm = x + (w / 2); // x-middle
const ym = y + (h / 2); // y-middle
context.moveTo(x, ym);
context.bezierCurveTo(x, ym - oy, xm - ox, y, xm, y);
context.bezierCurveTo(xm + ox, y, xe, ym - oy, xe, ym);
context.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
context.bezierCurveTo(xm - ox, ye, x, ym + oy, x, ym);
context.closePath();
if (data.fill)
{
context.globalAlpha = data.fillAlpha * worldAlpha;
context.fillStyle = `#${(`00000${(fillColor | 0).toString(16)}`).substr(-6)}`;
context.fill();
}
if (data.lineWidth)
{
context.globalAlpha = data.lineAlpha * worldAlpha;
context.strokeStyle = `#${(`00000${(lineColor | 0).toString(16)}`).substr(-6)}`;
context.stroke();
}
}
else if (data.type === SHAPES.RREC)
{
const rx = shape.x;
const ry = shape.y;
const width = shape.width;
const height = shape.height;
let radius = shape.radius;
const maxRadius = Math.min(width, height) / 2 | 0;
radius = radius > maxRadius ? maxRadius : radius;
context.beginPath();
context.moveTo(rx, ry + radius);
context.lineTo(rx, ry + height - radius);
context.quadraticCurveTo(rx, ry + height, rx + radius, ry + height);
context.lineTo(rx + width - radius, ry + height);
context.quadraticCurveTo(rx + width, ry + height, rx + width, ry + height - radius);
context.lineTo(rx + width, ry + radius);
context.quadraticCurveTo(rx + width, ry, rx + width - radius, ry);
context.lineTo(rx + radius, ry);
context.quadraticCurveTo(rx, ry, rx, ry + radius);
context.closePath();
if (data.fillColor || data.fillColor === 0)
{
context.globalAlpha = data.fillAlpha * worldAlpha;
context.fillStyle = `#${(`00000${(fillColor | 0).toString(16)}`).substr(-6)}`;
context.fill();
}
if (data.lineWidth)
{
context.globalAlpha = data.lineAlpha * worldAlpha;
context.strokeStyle = `#${(`00000${(lineColor | 0).toString(16)}`).substr(-6)}`;
context.stroke();
}
}
}
}
/**
* Updates the tint of a graphics object
*
* @private
* @param {PIXI.Graphics} graphics - the graphics that will have its tint updated
*/
updateGraphicsTint(graphics)
{
graphics._prevTint = graphics.tint;
const tintR = ((graphics.tint >> 16) & 0xFF) / 255;
const tintG = ((graphics.tint >> 8) & 0xFF) / 255;
const tintB = (graphics.tint & 0xFF) / 255;
for (let i = 0; i < graphics.graphicsData.length; ++i)
{
const data = graphics.graphicsData[i];
const fillColor = data.fillColor | 0;
const lineColor = data.lineColor | 0;
// super inline cos im an optimization NAZI :)
data._fillTint = (
(((fillColor >> 16) & 0xFF) / 255 * tintR * 255 << 16)
+ (((fillColor >> 8) & 0xFF) / 255 * tintG * 255 << 8)
+ (((fillColor & 0xFF) / 255) * tintB * 255)
);
data._lineTint = (
(((lineColor >> 16) & 0xFF) / 255 * tintR * 255 << 16)
+ (((lineColor >> 8) & 0xFF) / 255 * tintG * 255 << 8)
+ (((lineColor & 0xFF) / 255) * tintB * 255)
);
}
}
/**
* Renders a polygon.
*
* @param {PIXI.Point[]} points - The points to render
* @param {boolean} close - Should the polygon be closed
* @param {CanvasRenderingContext2D} context - The rendering context to use
*/
renderPolygon(points, close, context)
{
context.moveTo(points[0], points[1]);
for (let j = 1; j < points.length / 2; ++j)
{
context.lineTo(points[j * 2], points[(j * 2) + 1]);
}
if (close)
{
context.closePath();
}
}
/**
* destroy graphics object
*
*/
destroy()
{
this.renderer = null;
}
}
CanvasRenderer.registerPlugin('graphics', CanvasGraphicsRenderer);