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195 行
6.9 KiB

using System;
using System.Collections.Generic;
using UnityEngine.Rendering;
using UnityEngine.Experimental.Rendering.HDPipeline;
#if UNITY_EDITOR
using UnityEditor;
#endif
namespace UnityEngine.Experimental.Rendering
{
public class AtlasAllocator
{
private class AtlasNode
{
public AtlasNode m_RightChild = null;
public AtlasNode m_BottomChild = null;
public Vector4 m_Rect = new Vector4(0, 0, 0, 0); // x,y is width and height (scale) z,w offset into atlas (bias)
public AtlasNode Allocate(int width, int height)
{
// not a leaf node, try children
if (m_RightChild != null)
{
AtlasNode node = m_RightChild.Allocate(width, height);
if (node == null)
{
node = m_BottomChild.Allocate(width, height);
}
return node;
}
//leaf node, check for fit
if ((width <= m_Rect.x) && (height <= m_Rect.y))
{
// perform the split
m_RightChild = new AtlasNode();
m_BottomChild = new AtlasNode();
if (width > height) // logic to decide which way to split
{ // +--------+------+
m_RightChild.m_Rect.z = m_Rect.z + width; // | | |
m_RightChild.m_Rect.w = m_Rect.w; // +--------+------+
m_RightChild.m_Rect.x = m_Rect.x - width; // | |
m_RightChild.m_Rect.y = height; // | |
// +---------------+
m_BottomChild.m_Rect.z = m_Rect.z;
m_BottomChild.m_Rect.w = m_Rect.w + height;
m_BottomChild.m_Rect.x = m_Rect.x;
m_BottomChild.m_Rect.y = m_Rect.y - height;
}
else
{ // +---+-----------+
m_RightChild.m_Rect.z = m_Rect.z + width; // | | |
m_RightChild.m_Rect.w = m_Rect.w; // | | |
m_RightChild.m_Rect.x = m_Rect.x - width; // +---+ +
m_RightChild.m_Rect.y = m_Rect.y; // | | |
// +---+-----------+
m_BottomChild.m_Rect.z = m_Rect.z;
m_BottomChild.m_Rect.w = m_Rect.w + height;
m_BottomChild.m_Rect.x = width;
m_BottomChild.m_Rect.y = m_Rect.y - height;
}
m_Rect.x = width;
m_Rect.y = height;
return this;
}
return null;
}
public void Release()
{
if (m_RightChild != null)
{
m_RightChild.Release();
m_BottomChild.Release();
}
m_RightChild = null;
m_BottomChild = null;
}
}
private AtlasNode m_Root;
private int m_Width;
private int m_Height;
public AtlasAllocator(int width, int height)
{
m_Root = new AtlasNode();
m_Root.m_Rect.Set(width, height, 0, 0);
m_Width = width;
m_Height = height;
}
public bool Allocate(ref Vector4 result, int width, int height)
{
AtlasNode node = m_Root.Allocate(width, height);
if (node != null)
{
result = node.m_Rect;
return true;
}
else
{
result = Vector4.zero;
return false;
}
}
public void Release()
{
m_Root.Release();
m_Root = new AtlasNode();
m_Root.m_Rect.Set(m_Width, m_Height, 0, 0);
}
}
public class Texture2DAtlas
{
private RTHandleSystem.RTHandle m_AtlasTexture = null;
private int m_Width;
private int m_Height;
private RenderTextureFormat m_Format;
private AtlasAllocator m_AtlasAllocator = null;
private Dictionary<IntPtr, Vector4> m_AllocationCache = new Dictionary<IntPtr, Vector4>();
public RTHandleSystem.RTHandle AtlasTexture
{
get
{
return m_AtlasTexture;
}
}
public Texture2DAtlas(int width, int height, RenderTextureFormat format)
{
m_Width = width;
m_Height = height;
m_Format = format;
m_AtlasTexture = RTHandles.Alloc(m_Width,
m_Height,
1,
DepthBits.None,
m_Format,
FilterMode.Point,
TextureWrapMode.Clamp,
TextureDimension.Tex2D,
false,
false,
true,
false);
m_AtlasAllocator = new AtlasAllocator(width, height);
}
public void Release()
{
ResetAllocator();
RTHandles.Release(m_AtlasTexture);
}
public void ResetAllocator()
{
m_AtlasAllocator.Release();
m_AllocationCache.Clear();
}
public bool AddTexture(CommandBuffer cmd, ref Vector4 scaleBias, Texture texture)
{
IntPtr key = texture.GetNativeTexturePtr();
if (!m_AllocationCache.TryGetValue(key, out scaleBias))
{
int width = texture.width;
int height = texture.height;
if (m_AtlasAllocator.Allocate(ref scaleBias, width, height))
{
scaleBias.Scale(new Vector4(1.0f / m_Width, 1.0f / m_Height, 1.0f / m_Width, 1.0f / m_Height));
for (int mipLevel = 0; mipLevel < (texture as Texture2D).mipmapCount; mipLevel++)
{
cmd.SetRenderTarget(m_AtlasTexture, mipLevel);
HDUtils.BlitQuad(cmd, texture, new Vector4(1, 1, 0, 0), scaleBias, mipLevel, false);
}
m_AllocationCache.Add(key, scaleBias);
return true;
}
else
{
return false;
}
}
return true;
}
}
}