In an earlier part of this chapter, we discussed making calls to the Emscripten WebAssembly app from a shell template. Now that you know how to make the interaction work between JavaScript and WebAssembly, we can add a canvas element back into the template and start to manipulate that canvas using the WebAssembly module. We are going to create a new .c file that will call a JavaScript function passing it an x and y coordinate. The JavaScript function will manipulate a spaceship image, moving it around the canvas. We will also create a brand new shell file called canvas_shell.html.
As we did for the previous version of our shell, we will start by breaking this file down into four sections to discuss it at a high level. We will then discuss the essential parts of this file a piece at a time.
- The beginning of the HTML file starts with...
