Firstborn/Library/PackageCache/com.unity.render-pipelines..../Runtime/DeferredTiler.cs

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2023-03-28 13:24:16 -04:00
using Unity.Collections;
using Unity.Collections.LowLevel.Unsafe;
using System.Runtime.CompilerServices;
using Unity.Mathematics;
using static Unity.Mathematics.math;
namespace UnityEngine.Rendering.Universal.Internal
{
// This structure is designed to be Burst friendly.
// It can be copied by value.
internal struct DeferredTiler
{
// Precomputed light data
internal struct PrePunctualLight
{
// view-space position.
public float3 posVS;
// Radius in world unit.
public float radius;
// Distance between closest bound of the light and the camera. Used for sorting lights front-to-back.
public float minDist;
// Projected position of the sphere centre on the screen (near plane).
public float2 screenPos;
// Index into renderingData.lightData.visibleLights native array.
public ushort visLightIndex;
}
enum ClipResult
{
Unknown,
In,
Out,
}
int m_TilePixelWidth;
int m_TilePixelHeight;
int m_TileXCount;
int m_TileYCount;
// Fixed header size in uint in m_TileHeader.
// Only finest tiler requires to store extra per-tile information (light list depth range, bitmask for 2.5D culling).
int m_TileHeaderSize;
// Indicative average lights per tile. Only used when initializing the size of m_DataTile for the first time.
int m_AvgLightPerTile;
// 0, 1 or 2 (see DeferredConfig.kTilerDepth)
int m_TilerLevel;
// Camera frustum planes, adjusted to account for tile size.
FrustumPlanes m_FrustumPlanes;
// Are we dealing with an orthographic projection.
bool m_IsOrthographic;
// Atomic counters are put in a NativeArray so they can be accessed/shared from jobs.
// [0] maxLightPerTile: Only valid for finest tiler: max light counter per tile. Reset every frame.
// [1] tileDataSize: reset every frame.
// [2] tileDataCapacity: extra amount of memory required by each tiler (depends on number of lights visible). Externally maintained.
[Unity.Collections.LowLevel.Unsafe.NativeDisableContainerSafetyRestriction]
NativeArray<int> m_Counters;
// Store all visible light indices for all tiles.
// (currently) Contains sequential blocks of ushort values (light indices and optionally lightDepthRange), for each tile
// For example for platforms using 16x16px tiles:
// in a finest tiler DeferredLights.m_Tilers[0] ( 16x16px tiles), each tile will use a block of 1 * 1 * 32 = 32 ushort values
// in an intermediate tiler DeferredLights.m_Tilers[1] ( 64x64px tiles), each tile will use a block of 4 * 4 * 32 = 512 ushort values
// in a coarsest tiler DeferredLights.m_Tilers[2] (256x256px tiles), each tile will use a block of 16 * 16 * 32 = 8192 ushort values
[Unity.Collections.LowLevel.Unsafe.NativeDisableContainerSafetyRestriction]
NativeArray<ushort> m_TileData;
// Store tile header (fixed size per tile)
// light offset, light count, optionally additional per-tile "header" values.
[Unity.Collections.LowLevel.Unsafe.NativeDisableContainerSafetyRestriction]
NativeArray<uint> m_TileHeaders;
// Precompute tile data.
[Unity.Collections.LowLevel.Unsafe.NativeDisableContainerSafetyRestriction]
NativeArray<PreTile> m_PreTiles;
public DeferredTiler(int tilePixelWidth, int tilePixelHeight, int avgLightPerTile, int tilerLevel)
{
m_TilePixelWidth = tilePixelWidth;
m_TilePixelHeight = tilePixelHeight;
m_TileXCount = 0;
m_TileYCount = 0;
// Finest tiler (at index 0) computes extra tile data stored into the header, so it requires more space. See CullFinalLights() vs CullIntermediateLights().
// Finest tiler: lightListOffset, lightCount, listDepthRange, listBitMask
// Coarse tilers: lightListOffset, lightCount
m_TileHeaderSize = tilerLevel == 0 ? 4 : 2;
m_AvgLightPerTile = avgLightPerTile;
m_TilerLevel = tilerLevel;
m_FrustumPlanes = new FrustumPlanes { left = 0, right = 0, bottom = 0, top = 0, zNear = 0, zFar = 0 };
m_IsOrthographic = false;
m_Counters = new NativeArray<int>();
m_TileData = new NativeArray<ushort>();
m_TileHeaders = new NativeArray<uint>();
m_PreTiles = new NativeArray<PreTile>();
}
public int TilerLevel
{
get { return m_TilerLevel; }
}
public int TileXCount
{
get { return m_TileXCount; }
}
public int TileYCount
{
get { return m_TileYCount; }
}
public int TilePixelWidth
{
get { return m_TilePixelWidth; }
}
public int TilePixelHeight
{
get { return m_TilePixelHeight; }
}
public int TileHeaderSize
{
get { return m_TileHeaderSize; }
}
public int MaxLightPerTile
{
get { return m_Counters.IsCreated ? m_Counters[0] : 0; }
}
public int TileDataCapacity
{
get { return m_Counters.IsCreated ? m_Counters[2] : 0; }
}
public NativeArray<ushort> Tiles
{
get { return m_TileData; }
}
public NativeArray<uint> TileHeaders
{
get { return m_TileHeaders; }
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void GetTileOffsetAndCount(int i, int j, out int offset, out int count)
{
int headerOffset = GetTileHeaderOffset(i, j);
offset = (int)m_TileHeaders[headerOffset + 0];
count = (int)m_TileHeaders[headerOffset + 1];
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public int GetTileHeaderOffset(int i, int j)
{
return (i + j * m_TileXCount) * m_TileHeaderSize;
}
public void Setup(int tileDataCapacity)
{
if (tileDataCapacity <= 0)
tileDataCapacity = m_TileXCount * m_TileYCount * m_AvgLightPerTile;
m_Counters = new NativeArray<int>(3, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
m_TileData = new NativeArray<ushort>(tileDataCapacity, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
m_TileHeaders = new NativeArray<uint>(m_TileXCount * m_TileYCount * m_TileHeaderSize, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
m_Counters[0] = 0;
m_Counters[1] = 0;
m_Counters[2] = tileDataCapacity;
}
public void OnCameraCleanup()
{
if (m_TileHeaders.IsCreated)
m_TileHeaders.Dispose();
if (m_TileData.IsCreated)
m_TileData.Dispose();
if (m_Counters.IsCreated)
m_Counters.Dispose();
}
public void PrecomputeTiles(Matrix4x4 proj, bool isOrthographic, int renderWidth, int renderHeight)
{
m_TileXCount = (renderWidth + m_TilePixelWidth - 1) / m_TilePixelWidth;
m_TileYCount = (renderHeight + m_TilePixelHeight - 1) / m_TilePixelHeight;
m_PreTiles = DeferredShaderData.instance.GetPreTiles(m_TilerLevel, m_TileXCount * m_TileYCount);
// Adjust render width and height to account for tile size expanding over the screen (tiles have a fixed pixel size).
int adjustedRenderWidth = Align(renderWidth, m_TilePixelWidth);
int adjustedRenderHeight = Align(renderHeight, m_TilePixelHeight);
// Now adjust the right and bottom clipping planes.
m_FrustumPlanes = proj.decomposeProjection;
m_FrustumPlanes.right = m_FrustumPlanes.left + (m_FrustumPlanes.right - m_FrustumPlanes.left) * (adjustedRenderWidth / (float)renderWidth);
m_FrustumPlanes.bottom = m_FrustumPlanes.top + (m_FrustumPlanes.bottom - m_FrustumPlanes.top) * (adjustedRenderHeight / (float)renderHeight);
m_IsOrthographic = isOrthographic;
// Tile size in world units.
float tileWidthWS = (m_FrustumPlanes.right - m_FrustumPlanes.left) / m_TileXCount;
float tileHeightWS = (m_FrustumPlanes.top - m_FrustumPlanes.bottom) / m_TileYCount;
if (!isOrthographic) // perspective
{
for (int j = 0; j < m_TileYCount; ++j)
{
float tileTop = m_FrustumPlanes.top - tileHeightWS * j;
float tileBottom = tileTop - tileHeightWS;
for (int i = 0; i < m_TileXCount; ++i)
{
float tileLeft = m_FrustumPlanes.left + tileWidthWS * i;
float tileRight = tileLeft + tileWidthWS;
// Camera view space is always OpenGL RH coordinates system.
// In view space with perspective projection, all planes pass by (0,0,0).
PreTile preTile;
preTile.planeLeft = MakePlane(new float3(tileLeft, tileBottom, -m_FrustumPlanes.zNear), new float3(tileLeft, tileTop, -m_FrustumPlanes.zNear));
preTile.planeRight = MakePlane(new float3(tileRight, tileTop, -m_FrustumPlanes.zNear), new float3(tileRight, tileBottom, -m_FrustumPlanes.zNear));
preTile.planeBottom = MakePlane(new float3(tileRight, tileBottom, -m_FrustumPlanes.zNear), new float3(tileLeft, tileBottom, -m_FrustumPlanes.zNear));
preTile.planeTop = MakePlane(new float3(tileLeft, tileTop, -m_FrustumPlanes.zNear), new float3(tileRight, tileTop, -m_FrustumPlanes.zNear));
m_PreTiles[i + j * m_TileXCount] = preTile;
}
}
}
else
{
for (int j = 0; j < m_TileYCount; ++j)
{
float tileTop = m_FrustumPlanes.top - tileHeightWS * j;
float tileBottom = tileTop - tileHeightWS;
for (int i = 0; i < m_TileXCount; ++i)
{
float tileLeft = m_FrustumPlanes.left + tileWidthWS * i;
float tileRight = tileLeft + tileWidthWS;
// Camera view space is always OpenGL RH coordinates system.
PreTile preTile;
preTile.planeLeft = MakePlane(new float3(tileLeft, tileBottom, -m_FrustumPlanes.zNear), new float3(tileLeft, tileBottom, -m_FrustumPlanes.zNear - 1.0f), new float3(tileLeft, tileTop, -m_FrustumPlanes.zNear));
preTile.planeRight = MakePlane(new float3(tileRight, tileTop, -m_FrustumPlanes.zNear), new float3(tileRight, tileTop, -m_FrustumPlanes.zNear - 1.0f), new float3(tileRight, tileBottom, -m_FrustumPlanes.zNear));
preTile.planeBottom = MakePlane(new float3(tileRight, tileBottom, -m_FrustumPlanes.zNear), new float3(tileRight, tileBottom, -m_FrustumPlanes.zNear - 1.0f), new float3(tileLeft, tileBottom, -m_FrustumPlanes.zNear));
preTile.planeTop = MakePlane(new float3(tileLeft, tileTop, -m_FrustumPlanes.zNear), new float3(tileLeft, tileTop, -m_FrustumPlanes.zNear - 1.0f), new float3(tileRight, tileTop, -m_FrustumPlanes.zNear));
m_PreTiles[i + j * m_TileXCount] = preTile;
}
}
}
}
// This differs from CullIntermediateLights in 3 ways:
// - tile-frustums/light intersection use different algorithm
// - depth range of the light shape intersecting the tile-frustums is output in the tile list header section
// - light indices written out are indexing visible_lights, rather than the array of PrePunctualLights.
unsafe public void CullFinalLights(ref NativeArray<PrePunctualLight> punctualLights,
ref NativeArray<ushort> lightIndices, int lightStartIndex, int lightCount,
int istart, int iend, int jstart, int jend)
{
// Interestingly, 2-3% faster when using unsafe arrays.
PrePunctualLight* _punctualLights = (PrePunctualLight*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(punctualLights);
ushort* _lightIndices = (ushort*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(lightIndices);
uint* _tileHeaders = (uint*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(m_TileHeaders);
if (lightCount == 0)
{
for (int j = jstart; j < jend; ++j)
for (int i = istart; i < iend; ++i)
{
int headerOffset = GetTileHeaderOffset(i, j);
_tileHeaders[headerOffset + 0] = 0;
_tileHeaders[headerOffset + 1] = 0;
_tileHeaders[headerOffset + 2] = 0;
_tileHeaders[headerOffset + 3] = 0;
}
return;
}
// Store culled lights in temporary buffer. Additionally store depth range of each light for a given tile too.
// the depth range is a 32bit mask, but packed into a 16bits value since the range of the light is continuous
// (only need to store first bit enabled, and count of enabled bits).
ushort* tiles = stackalloc ushort[lightCount * 2];
float2* depthRanges = stackalloc float2[lightCount];
int maxLightPerTile = 0; // for stats
int lightEndIndex = lightStartIndex + lightCount;
float2 tileSize = new float2((m_FrustumPlanes.right - m_FrustumPlanes.left) / m_TileXCount, (m_FrustumPlanes.top - m_FrustumPlanes.bottom) / m_TileYCount);
float2 tileExtents = tileSize * 0.5f;
float2 tileExtentsInv = new float2(1.0f / tileExtents.x, 1.0f / tileExtents.y);
for (int j = jstart; j < jend; ++j)
{
float tileYCentre = m_FrustumPlanes.top - (tileExtents.y + j * tileSize.y);
for (int i = istart; i < iend; ++i)
{
float tileXCentre = m_FrustumPlanes.left + tileExtents.x + i * tileSize.x;
PreTile preTile = m_PreTiles[i + j * m_TileXCount];
int culledLightCount = 0;
// For the current tile's light list, min&max depth range (absolute values).
float listMinDepth = float.MaxValue;
float listMaxDepth = -float.MaxValue;
// Duplicate the inner loop twice. Testing for the ortographic case inside the inner loop would cost an extra 8% otherwise.
// Missing C++ template argument here!
if (!m_IsOrthographic)
{
for (int vi = lightStartIndex; vi < lightEndIndex; ++vi)
{
ushort lightIndex = _lightIndices[vi];
PrePunctualLight ppl = _punctualLights[lightIndex];
// Offset tileCentre toward the light to calculate a more conservative minMax depth bound,
// but it must remains inside the tile and must not pass further than the light centre.
float2 tileCentre = new float2(tileXCentre, tileYCentre);
float2 dir = ppl.screenPos - tileCentre;
float2 d = abs(dir * tileExtentsInv);
float sInv = 1.0f / max3(d.x, d.y, 1.0f);
float3 tileOffCentre = new float3(tileCentre.x + dir.x * sInv, tileCentre.y + dir.y * sInv, -m_FrustumPlanes.zNear);
float3 tileOrigin = new float3(0.0f);
float t0, t1;
// This is more expensive than Clip() but allow to compute min&max depth range for the part of the light inside the tile.
if (!IntersectionLineSphere(ppl.posVS, ppl.radius, tileOrigin, tileOffCentre, out t0, out t1))
continue;
listMinDepth = listMinDepth < t0 ? listMinDepth : t0;
listMaxDepth = listMaxDepth > t1 ? listMaxDepth : t1;
depthRanges[culledLightCount] = new float2(t0, t1);
// Because this always output to the finest tiles, contrary to CullLights(),
// the result are indices into visibleLights, instead of indices into punctualLights.
tiles[culledLightCount] = ppl.visLightIndex;
++culledLightCount;
}
}
else
{
for (int vi = lightStartIndex; vi < lightEndIndex; ++vi)
{
ushort lightIndex = _lightIndices[vi];
PrePunctualLight ppl = _punctualLights[lightIndex];
// Offset tileCentre toward the light to calculate a more conservative minMax depth bound,
// but it must remains inside the tile and must not pass further than the light centre.
float2 tileCentre = new float2(tileXCentre, tileYCentre);
float2 dir = ppl.screenPos - tileCentre;
float2 d = abs(dir * tileExtentsInv);
float sInv = 1.0f / max3(d.x, d.y, 1.0f);
float3 tileOffCentre = new float3(0, 0, -m_FrustumPlanes.zNear);
float3 tileOrigin = new float3(tileCentre.x + dir.x * sInv, tileCentre.y + dir.y * sInv, 0.0f);
float t0, t1;
// This is more expensive than Clip() but allow to compute min&max depth range for the part of the light inside the tile.
if (!IntersectionLineSphere(ppl.posVS, ppl.radius, tileOrigin, tileOffCentre, out t0, out t1))
continue;
listMinDepth = listMinDepth < t0 ? listMinDepth : t0;
listMaxDepth = listMaxDepth > t1 ? listMaxDepth : t1;
depthRanges[culledLightCount] = new float2(t0, t1);
// Because this always output to the finest tiles, contrary to CullLights(),
// the result are indices into visibleLights, instead of indices into punctualLights.
tiles[culledLightCount] = ppl.visLightIndex;
++culledLightCount;
}
}
// Post-multiply by zNear to get actual world unit absolute depth values, then clamp to valid depth range.
listMinDepth = max2(listMinDepth * m_FrustumPlanes.zNear, m_FrustumPlanes.zNear);
listMaxDepth = min2(listMaxDepth * m_FrustumPlanes.zNear, m_FrustumPlanes.zFar);
// Calculate bitmask for 2.5D culling.
uint bitMask = 0;
float depthRangeInv = 1.0f / (listMaxDepth - listMinDepth);
for (int culledLightIndex = 0; culledLightIndex < culledLightCount; ++culledLightIndex)
{
float lightMinDepth = max2(depthRanges[culledLightIndex].x * m_FrustumPlanes.zNear, m_FrustumPlanes.zNear);
float lightMaxDepth = min2(depthRanges[culledLightIndex].y * m_FrustumPlanes.zNear, m_FrustumPlanes.zFar);
int firstBit = (int)((lightMinDepth - listMinDepth) * 32.0f * depthRangeInv);
int lastBit = (int)((lightMaxDepth - listMinDepth) * 32.0f * depthRangeInv);
int bitCount = min(lastBit - firstBit + 1, 32 - firstBit);
bitMask |= (uint)((0xFFFFFFFF >> (32 - bitCount)) << firstBit);
tiles[culledLightCount + culledLightIndex] = (ushort)((uint)firstBit | (uint)(bitCount << 8));
}
// As listMinDepth and listMaxDepth are used to calculate the geometry 2.5D bitmask,
// we can optimize the shader execution (TileDepthInfo.shader) by refactoring the calculation.
// int bitIndex = 32.0h * (geoDepth - listMinDepth) / (listMaxDepth - listMinDepth);
// Equivalent to:
// a = 32.0 / (listMaxDepth - listMinDepth)
// b = -listMinDepth * 32.0 / (listMaxDepth - listMinDepth)
// int bitIndex = geoDepth * a + b;
float a = 32.0f * depthRangeInv;
float b = -listMinDepth * a;
int tileDataSize = culledLightCount * 2;
int tileOffset = culledLightCount > 0 ? AddTileData(tiles, ref tileDataSize) : 0;
int headerOffset = GetTileHeaderOffset(i, j);
_tileHeaders[headerOffset + 0] = (uint)tileOffset;
_tileHeaders[headerOffset + 1] = (uint)(tileDataSize == 0 ? 0 : culledLightCount);
_tileHeaders[headerOffset + 2] = _f32tof16(a) | (_f32tof16(b) << 16);
_tileHeaders[headerOffset + 3] = bitMask;
maxLightPerTile = max(maxLightPerTile, culledLightCount);
}
}
m_Counters[0] = max(m_Counters[0], maxLightPerTile); // TODO make it atomic
}
// TODO: finer culling for spot lights
unsafe public void CullIntermediateLights(ref NativeArray<PrePunctualLight> punctualLights,
ref NativeArray<ushort> lightIndices, int lightStartIndex, int lightCount,
int istart, int iend, int jstart, int jend)
{
// Interestingly, 2-3% faster when using unsafe arrays.
PrePunctualLight* _punctualLights = (PrePunctualLight*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(punctualLights);
ushort* _lightIndices = (ushort*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(lightIndices);
uint* _tileHeaders = (uint*)NativeArrayUnsafeUtility.GetUnsafeBufferPointerWithoutChecks(m_TileHeaders);
if (lightCount == 0)
{
for (int j = jstart; j < jend; ++j)
for (int i = istart; i < iend; ++i)
{
int headerOffset = GetTileHeaderOffset(i, j);
_tileHeaders[headerOffset + 0] = 0;
_tileHeaders[headerOffset + 1] = 0;
}
return;
}
// Store culled result in temporary buffer.
ushort* tiles = stackalloc ushort[lightCount];
int lightEndIndex = lightStartIndex + lightCount;
for (int j = jstart; j < jend; ++j)
{
for (int i = istart; i < iend; ++i)
{
PreTile preTile = m_PreTiles[i + j * m_TileXCount];
int culledLightCount = 0;
for (int vi = lightStartIndex; vi < lightEndIndex; ++vi)
{
ushort lightIndex = _lightIndices[vi];
PrePunctualLight ppl = _punctualLights[lightIndex];
// This is slightly faster than IntersectionLineSphere().
if (!Clip(ref preTile, ppl.posVS, ppl.radius))
continue;
tiles[culledLightCount] = lightIndex;
++culledLightCount;
}
// Copy the culled light list.
int tileOffset = culledLightCount > 0 ? AddTileData(tiles, ref culledLightCount) : 0;
int headerOffset = GetTileHeaderOffset(i, j);
_tileHeaders[headerOffset + 0] = (uint)tileOffset;
_tileHeaders[headerOffset + 1] = (uint)culledLightCount;
}
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
unsafe int AddTileData(ushort* lightData, ref int size)
{
int* _Counters = (int*)m_Counters.GetUnsafePtr();
int tileDataSize = System.Threading.Interlocked.Add(ref _Counters[1], size);
int offset = tileDataSize - size;
if (tileDataSize <= m_TileData.Length)
{
ushort* _TileData = (ushort*)m_TileData.GetUnsafePtr();
UnsafeUtility.MemCpy(_TileData + offset, lightData, size * 2);
return offset;
}
else
{
// Buffer overflow. Ignore data to add.
// Gracefully increasing the buffer size is possible but costs extra CPU time (see commented code below) due to the needed critical section.
m_Counters[2] = max(m_Counters[2], tileDataSize); // use an atomic max instead?
size = 0;
return 0;
}
/*
lock (this)
{
int offset = m_TileDataSize;
m_TileDataSize += size;
ushort* _TileData = (ushort*)m_TileData.GetUnsafePtr();
if (m_TileDataSize > m_TileDataCapacity)
{
m_TileDataCapacity = max(m_TileDataSize, m_TileDataCapacity * 2);
NativeArray<ushort> newTileData = new NativeArray<ushort>(m_TileDataCapacity, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
ushort* _newTileData = (ushort*)newTileData.GetUnsafePtr();
UnsafeUtility.MemCpy(_newTileData, _TileData, offset * 2);
m_TileData.Dispose();
m_TileData = newTileData;
_TileData = _newTileData;
}
UnsafeUtility.MemCpy(_TileData + offset, lightData, size * 2);
return offset;
}
*/
}
// Return parametric intersection between a sphere and a line.
// The intersections points P0 and P1 are:
// P0 = raySource + rayDirection * t0.
// P1 = raySource + rayDirection * t1.
[MethodImpl(MethodImplOptions.AggressiveInlining)]
unsafe static bool IntersectionLineSphere(float3 centre, float radius, float3 raySource, float3 rayDirection, out float t0, out float t1)
{
float A = dot(rayDirection, rayDirection); // always >= 0
float B = dot(raySource - centre, rayDirection);
float C = dot(raySource, raySource)
+ dot(centre, centre)
- (radius * radius)
- 2 * dot(raySource, centre);
float discriminant = (B * B) - A * C;
if (discriminant > 0)
{
float sqrt_discriminant = sqrt(discriminant);
float A_inv = 1.0f / A;
t0 = (-B - sqrt_discriminant) * A_inv;
t1 = (-B + sqrt_discriminant) * A_inv;
return true;
}
else
{
t0 = 0.0f; // invalid
t1 = 0.0f; // invalid
return false;
}
}
// Clip a sphere against a 2D tile. Near and far planes are ignored (already tested).
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static bool Clip(ref PreTile tile, float3 posVS, float radius)
{
// Simplified clipping code, only deals with 4 clipping planes.
// zNear and zFar clipping planes are ignored as presumably the light is already visible to the camera frustum.
float radiusSq = radius * radius;
int insideCount = 0;
ClipResult res;
res = ClipPartial(tile.planeLeft, tile.planeBottom, tile.planeTop, posVS, radius, radiusSq, ref insideCount);
if (res != ClipResult.Unknown)
return res == ClipResult.In;
res = ClipPartial(tile.planeRight, tile.planeBottom, tile.planeTop, posVS, radius, radiusSq, ref insideCount);
if (res != ClipResult.Unknown)
return res == ClipResult.In;
res = ClipPartial(tile.planeTop, tile.planeLeft, tile.planeRight, posVS, radius, radiusSq, ref insideCount);
if (res != ClipResult.Unknown)
return res == ClipResult.In;
res = ClipPartial(tile.planeBottom, tile.planeLeft, tile.planeRight, posVS, radius, radiusSq, ref insideCount);
if (res != ClipResult.Unknown)
return res == ClipResult.In;
return insideCount == 4;
}
// Internal function to clip against 1 plane of a cube, with additional 2 side planes for false-positive detection (normally 4 planes, but near and far planes are ignored).
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static ClipResult ClipPartial(float4 plane, float4 sidePlaneA, float4 sidePlaneB, float3 posVS, float radius, float radiusSq, ref int insideCount)
{
float d = DistanceToPlane(plane, posVS);
if (d + radius <= 0.0f) // completely outside
return ClipResult.Out;
else if (d < 0.0f) // intersection: further check: only need to consider case where more than half the sphere is outside
{
float3 p = posVS - plane.xyz * d;
float rSq = radiusSq - d * d;
if (SignedSq(DistanceToPlane(sidePlaneA, p)) >= -rSq
&& SignedSq(DistanceToPlane(sidePlaneB, p)) >= -rSq)
return ClipResult.In;
}
else // consider as good as completely inside
++insideCount;
return ClipResult.Unknown;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float4 MakePlane(float3 pb, float3 pc)
{
float3 v0 = pb;
float3 v1 = pc;
float3 n = cross(v0, v1);
n = normalize(n);
// The planes pass all by the origin.
return new float4(n.x, n.y, n.z, 0.0f);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float4 MakePlane(float3 pa, float3 pb, float3 pc)
{
float3 v0 = pb - pa;
float3 v1 = pc - pa;
float3 n = cross(v0, v1);
n = normalize(n);
return new float4(n.x, n.y, n.z, -dot(n, pa));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float DistanceToPlane(float4 plane, float3 p)
{
return plane.x * p.x + plane.y * p.y + plane.z * p.z + plane.w;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float SignedSq(float f)
{
// slower!
//return Mathf.Sign(f) * (f * f);
return (f < 0.0f ? -1.0f : 1.0f) * (f * f);
}
// Unity.Mathematics.max() function calls Single_IsNan() which significantly slow down the code (up to 20% of CullFinalLights())!
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float min2(float a, float b)
{
return a < b ? a : b;
}
// Unity.Mathematics.min() function calls Single_IsNan() which significantly slow down the code (up to 20% of CullFinalLights())!
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float max2(float a, float b)
{
return a > b ? a : b;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float max3(float a, float b, float c)
{
return a > b ? (a > c ? a : c) : (b > c ? b : c);
}
// This is copy-pasted from Unity.Mathematics.math.f32tof16(), but use min2() function that does not check for NaN (which would consume 10% of the execution time of CullFinalLights()).
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint _f32tof16(float x)
{
const int infinity_32 = 255 << 23;
const uint msk = 0x7FFFF000u;
uint ux = asuint(x);
uint uux = ux & msk;
uint h = (uint)(asuint(min2(asfloat(uux) * 1.92592994e-34f, 260042752.0f)) + 0x1000) >> 13; // Clamp to signed infinity if overflowed
h = select(h, select(0x7c00u, 0x7e00u, (int)uux > infinity_32), (int)uux >= infinity_32); // NaN->qNaN and Inf->Inf
return h | (ux & ~msk) >> 16;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static int Align(int s, int alignment)
{
return ((s + alignment - 1) / alignment) * alignment;
}
}
}