Hosting Solutions
mobile_logo Table of Contents
seal_frontseal_back

Compositing on the Canvas

In this exercise you will learn about the global compositing properties available for the canvas element through JavaScript. Compositing deals with setting global transparency, asset stacking and controlling how your assets will interact with one another when they overlap on your canvas. globalAlpha 0.0 - 1.0; globalCompositeOperation source-atop || source-in || source-out || source-over (default) || destination-atop || destination-in || destination-out || destination-over || lighter || copy || xor <!DOCTYPE html> <html> <head> <style> body{ margin:10px; background:#666; } #my_canvas{ background:#FFF; border:#000 1px solid; } </style> <script> function draw(){ var ctx = document.getElementById('my_canvas').getContext('2d'); ctx.globalAlpha = 1; ctx.fillStyle = "magenta"; ctx.fillRect(20, 20, 100, 100); ctx.globalCompositeOperation = "xor"; ctx.fillStyle = "blue"; ctx.fillRect(50, 50, 100, 100); } window.onload = draw; </script> </head> <body> <canvas id="my_canvas" width="500" height="350"></canvas> </body> </html>
thumb

JavaScript Videos

Canvas Programming

2D Context Object and Rectangle MethodsFill and Stroke Styles Color Gradient PatternLine Styles for Lines and StrokesBuilding and Drawing PathsDrawing Images and VideosDrawing Text on CanvasRendering Shadows on CanvasCanvas Transformation EffectsPixel Manipulation on CanvasCompositing on the CanvasDynamic Centering and Alignment on the CanvasCanvas Animation and App InitializationObject Oriented Assets OOP on CanvasDetect Mouse Coordinates on CanvasAnimated Background Layers on Canvas TutorialKeyboard Control and MovementJSON Object Arrays and Loops on CanvasHit Detection Mouse Touch Over Object ArraysCollision Detection Hit Game EnemiesParticle Effect System Tutorial Snow Falling AnimationInteractive Canvas Imaging Applications JavaScript PHP TutorialCircular Progress Loader Canvas JavaScript Programming Tutorial