Function drawImageColor

src/engineDraw.js:1205–1255

Helper function to draw an image with color and additive color applied * This is slower then normal drawImage when color is applied * @param {CanvasRenderingContext2D|OffscreenCanvasRenderingContext2D} context * @param {HTMLImageElement|OffscreenCanvas} image * @param {number} sx

(context, image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight, color, additiveColor, bleed=0)

    *  @param {number} [bleed] - How many pixels to shrink the source, used to fix bleeding
 *  @memberof Draw */
function drawImageColor(context, image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight, color, additiveColor, bleed=0)
{
    const sx2 = bleed;
    const sy2 = bleed;
    sWidth  = max(1,sWidth|0);
    sHeight = max(1,sHeight|0);
    const sWidth2  = sWidth  - 2*bleed;
    const sHeight2 = sHeight - 2*bleed;
    if (!canvasColorTiles || (additiveColor ? isWhite(color.add(additiveColor)) && additiveColor.a <= 0 : isWhite(color)))
    {
        // white texture with no additive alpha, no need to tint
        context.globalAlpha = color.a;
        context.drawImage(image, sx+sx2, sy+sy2, sWidth2, sHeight2, dx, dy, dWidth, dHeight);
        context.globalAlpha = 1;
    }
    else
    {
        // copy to offscreen canvas
        workReadCanvas.width = sWidth;
        workReadCanvas.height = sHeight;
        workReadContext.drawImage(image, sx|0, sy|0, sWidth, sHeight, 0, 0, sWidth, sHeight);

        // tint image using offscreen work context
        const imageData = workReadContext.getImageData(0, 0, sWidth, sHeight);
        const data = imageData.data;
        if (additiveColor && !isBlack(additiveColor))
        {
            // slower path with additive color
            const colorMultiply = [color.r, color.g, color.b, color.a];
            const colorAdd = [additiveColor.r * 255, additiveColor.g * 255, additiveColor.b * 255, additiveColor.a * 255];
            for (let i = 0; i < data.length; ++i)
                data[i] = data[i] * colorMultiply[i&3] + colorAdd[i&3] |0;
            workReadContext.putImageData(imageData, 0, 0);
            context.drawImage(workReadCanvas, sx2, sy2, sWidth2, sHeight2, dx, dy, dWidth, dHeight);
        }
        else
        {
            // faster path with no additive color
            for (let i = 0; i < data.length; i+=4)
            {
                data[i  ] *= color.r;
                data[i+1] *= color.g;
                data[i+2] *= color.b;
            }
            workReadContext.putImageData(imageData, 0, 0);
            context.globalAlpha = color.a;
            context.drawImage(workReadCanvas, sx2, sy2, sWidth2, sHeight2, dx, dy, dWidth, dHeight);
            context.globalAlpha = 1;
        }
    }
}


/** Returns true if fullscreen mode is active