private static Packer.Block[] ComputePack(IList <Texture2D> textures, out int width, out int height)
{
int num = textures.Count;
Packer.Block[] blocks = new Packer.Block[num];
for (int i = 0; i < num; i++)
{
Texture2D tex = textures[i];
blocks[i] = new Packer.Block()
{
w = tex.width, h = tex.height, x = 0, y = 0, i = i,
};
}
Array.Sort(blocks, new BlockComparer());
Packer packer = new Packer();
packer.Fit(blocks, out width, out height);
return(blocks);
}
public static Rect[] PackTexturesCompute(out Texture result, IList <Texture2D> textures,
int maximumAtlasSize = 2048)
{
int width;
int height;
Packer.Block[] blocks = ComputePack(textures, out width, out height);
if (width < height)
{
throw new Exception("error");
}
float scale = 1;
if (width > maximumAtlasSize)
{
scale = (float)maximumAtlasSize / width;
width = maximumAtlasSize;
height = (int)(height * scale);
}
width = PowerOfTwo(width);
height = PowerOfTwo(height);
RenderTexture rt = new RenderTexture(width, height, 0)
{
enableRandomWrite = true,
useMipMap = true,
autoGenerateMips = false
};
rt.Create();
ComputeShader cs = _computeShader;
cs.SetTexture(_kernelId, "Target", rt);
cs.SetFloat("Scale", 1 / scale);
int len = textures.Count;
Rect[] ret = new Rect[len];
for (int i = 0; i < len; i++)
{
Packer.Block block = blocks[i];
Texture2D tex = textures[block.i];
cs.SetTexture(_kernelId, "Pixels", tex);
block *= scale;
cs.SetInts("Offset", block.x, block.y);
cs.Dispatch(_kernelId, block.w / 8, block.h / 8, 1);
ret[block.i] = new Rect(block.x / (float)width, block.y / (float)height, block.w / (float)width,
block.h / (float)height);
}
rt.GenerateMips();
result = rt;
//result = new Texture2D(width, height);
//RenderTexture tmp = RenderTexture.active;
//RenderTexture.active = rt;
////TODO: ！！！
//result.ReadPixels(new Rect(0, 0, width, height), 0, 0);
//UnityEngine.Profiling.Profiler.BeginSample("ReadPixels");
//result.Apply(false, true);
//UnityEngine.Profiling.Profiler.EndSample();
//RenderTexture.active = tmp;
return(ret);
}