我想做下面这样的事情...
// commmands - context commands to build primitives.
// See comments in loop for example.
function DrawToCanvas(commands, height, width){
var canvas = document.createElement("canvas");
canvas.width = inWidth;
canvas.height = inHeight;
var context = canvas.getContext("2d")
for(var i = 0; i < commands.length; i++){
// Do Stuff like
// context.beginPath();
// context.moveTo(25,25);
// context.lineTo(105,25);
// context.lineTo(25,105);
// context.fill();
// context.commands[i] <- Something like this
}
return canvas;
}
是否有一些等效于上下文命令[i]等...
我在想如果这是不可能的,另一种选择是传递回调函数。像...
function MakeALine(){
var newLineAsCanvas = DrawToCanvas(100,100,function(context){
context.beginPath();
context.moveTo(25,25);
// etc...
}
}
做这样的事情最好的方法是什么?
我有点困惑你在追求什么,但 javascript 调用命令可能会有所帮助。
var commands = [];
commands.push(function(context) {
context.beginPath();
});
commands.push(function(context) {
context.moveTo(25,25);
context.lineTo(105,25);
context.lineTo(25,105);
});
commands.push(function(context) {
context.fill();
});
document.body.appendChild(DrawToCanvas(commands, 300, 300));
function DrawToCanvas(commands, height, width){
var canvas = document.createElement("canvas");
canvas.width = width;
canvas.height = height;
var context = canvas.getContext("2d")
for(var i = 0; i < commands.length; i++){
commands[i].call(this, context);
}
return canvas;
}