有3x3图像。该CanvasPixelArray是:Canvas PutImageData颜色丢失,无/低alpha
[12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255,12,24,48,255]
我改变所有像素的alpha为0,回来:
bobs = this.gfx.getImageData(0,0,3,3).data
for (a=3;a<bobs.data.length;a+=4)
bobs.data[a] = 0
this.gfx.putImageData(bobs,0,0)
bobs = this.gfx.getImageData(0,0,3,3).data
for (a=3;a<bobs.data.length;a+=4)
bobs.data[a] = 255
this.gfx.putImageData(bobs,0,0)
所有像素都变成了黑色。浏览器将颜色更改为黑色以节省内存。有没有办法来防止这种情况,或者我应该保存重复?
你能详细解释一下上下文吗?你需要在哪里使用这个?在http://jsfiddle.net/上有一个具体的例子可能会很酷。 – 2011-05-07 06:29:37