OpenSubdiv/examples/common/mtlPtexCommon.metal
2017-04-19 16:49:53 -07:00

384 lines
13 KiB
Metal

#line 0 "examples/common/mtlPtexCommon.metal"
//
// Copyright 2013 Pixar
//
// Licensed under the Apache License, Version 2.0 (the "Apache License")
// with the following modification; you may not use this file except in
// compliance with the Apache License and the following modification to it:
// Section 6. Trademarks. is deleted and replaced with:
//
// 6. Trademarks. This License does not grant permission to use the trade
// names, trademarks, service marks, or product names of the Licensor
// and its affiliates, except as required to comply with Section 4(c) of
// the License and to reproduce the content of the NOTICE file.
//
// You may obtain a copy of the Apache License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the Apache License with the above modification is
// distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the Apache License for the specific
// language governing permissions and limitations under the Apache License.
//
//----------------------------------------------------------
// Ptex.Common
//----------------------------------------------------------
template<typename T>
T lerp(T x, T y, float a)
{
return x + (y - x) * a;
}
template<>
int lerp<int>(int x, int y, float a)
{
return x + (y - x) * a;
}
struct PtexPacking {
int page;
int nMipmap;
int uOffset;
int vOffset;
int adjSizeDiffs[4];
int width;
int height;
};
PtexPacking getPtexPacking(device ushort* packings, int faceID)
{
PtexPacking packing;
packing.page = packings[faceID*6+0];
packing.nMipmap = packings[faceID*6+1];
packing.uOffset = packings[faceID*6+2];
packing.vOffset = packings[faceID*6+3];
int wh = packings[faceID*6+5];
packing.width = 1 << (wh >> 8);
packing.height = 1 << (wh & 0xff);
int adjSizeDiffs = packings[faceID*6+4];
packing.adjSizeDiffs[0] = (adjSizeDiffs >> 12) & 0xf;
packing.adjSizeDiffs[1] = (adjSizeDiffs >> 8) & 0xf;
packing.adjSizeDiffs[2] = (adjSizeDiffs >> 4) & 0xf;
packing.adjSizeDiffs[3] = (adjSizeDiffs >> 0) & 0xf;
return packing;
}
int computeMipmapOffsetU(int w, int level)
{
int width = 1 << w;
int m = (0x55555555 & (width | (width-1))) << (w&1);
int x = ~((1 << (w -((level-1)&~1))) - 1);
return (m & x) + ((level+1)&~1);
}
int computeMipmapOffsetV(int h, int level)
{
int height = 1 << h;
int m = (0x55555555 & (height-1)) << ((h+1)&1);;
int x = ~((1 << (h - (level&~1))) - 1 );
return (m & x) + (level&~1);
}
PtexPacking getPtexPacking(device ushort* packings, int faceID, int level)
{
PtexPacking packing;
packing.page = packings[faceID*6+0];
packing.nMipmap = packings[faceID*6+1];
packing.uOffset = packings[faceID*6+2];
packing.vOffset = packings[faceID*6+3];
//int sizeDiffs = packings[faceID*6+4];
int wh = packings[faceID*6+5];
int w = wh >> 8;
int h = wh & 0xff;
// clamp max level
level = min(level, packing.nMipmap);
packing.uOffset += computeMipmapOffsetU(w, level);
packing.vOffset += computeMipmapOffsetV(h, level);
packing.width = 1 << (w-level);
packing.height = 1 << (h-level);
return packing;
}
void evalQuadraticBSpline(float u, thread float3& B, thread float3& BU)
{
B[0] = 0.5 * (u*u - 2.0*u + 1);
B[1] = 0.5 + u - u*u;
B[2] = 0.5 * u*u;
BU[0] = u - 1.0;
BU[1] = 1 - 2 * u;
BU[2] = u;
}
// ----------------------------------------------------------------------------
// Non-Mipmap Lookups
// ----------------------------------------------------------------------------
template<typename Texture>
auto PtexLookupNearest(float4 patchCoord,
Texture data,
device ushort* packings) -> decltype(data.read(uint2(), int()))
{
float2 uv = clamp(patchCoord.xy, float2(0,0), float2(1,1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return float4(data.read(uint2(coords.x, coords.y), ppack.page));
}
template<typename Texture>
auto PtexLookupNearest(float4 patchCoord,
int level,
Texture data,
device ushort* packings) -> decltype(data.read(uint2(), int()))
{
float2 uv = clamp(patchCoord.xy, float2(0,0), float2(1,1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return float4(data.read(uint2(coords.x, coords.y), ppack.page));
}
template<typename Texture>
auto PtexLookupFast(float4 patchCoord,
Texture data,
device ushort* packings) -> decltype(data.sample(sampler(), float2(), int()))
{
constexpr sampler smp(coord::normalized, address::clamp_to_edge, filter::linear);
float2 uv = clamp(patchCoord.xy, float2(0), float2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID);
float2 coords = float2((uv.x * ppack.width + ppack.uOffset),
(uv.y * ppack.height + ppack.vOffset)) / float2(data.get_width(), data.get_height());
return data.sample(smp, coords, ppack.page);
}
template<typename Texture>
auto PtexLookupFast(float4 patchCoord,
float level,
Texture data,
device ushort* packings) -> decltype(data.sample(sampler(), float2(), int(), bias(level)))
{
constexpr sampler smp(coord::normalized, address::clamp_to_edge, filter::linear);
float2 uv = clamp(patchCoord.xy, float2(0), float2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2((uv.x * ppack.width + ppack.uOffset),
(uv.y * ppack.height + ppack.vOffset)) / float2(data.get_width(), data.get_height());
return data.sample(smp, coords, ppack.page, bias(level));
}
template<typename Texture>
auto PtexLookup(float4 patchCoord,
int level,
Texture data,
device ushort* packings) -> decltype(data.read(uint2(), int()))
{
float2 uv = clamp(patchCoord.xy, float2(0,0), float2(1,1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= float2(0.5, 0.5);
int c0X = int(floor(coords.x));
int c1X = int(ceil(coords.x));
int c0Y = int(floor(coords.y));
int c1Y = int(ceil(coords.y));
float t = coords.x - float(c0X);
float s = coords.y - float(c0Y);
const auto d0 = float4(data.read(uint2(c0X, c0Y), ppack.page));
const auto d1 = float4(data.read(uint2(c0X, c1Y), ppack.page));
const auto d2 = float4(data.read(uint2(c1X, c0Y), ppack.page));
const auto d3 = float4(data.read(uint2(c1X, c1Y), ppack.page));
const auto result = (1.0f-t) * ((1.0f-s)*d0 + s*d1) + t * ((1.0f-s)*d2 + s*d3);
return result;
}
template<typename Texture>
auto PtexLookupQuadratic(thread float4& du,
thread float4& dv,
float4 patchCoord,
int level,
Texture data,
device ushort* packings) -> decltype(data.read(uint2(), int()))
{
using dataType = decltype(data.read(uint2(), int()));
float2 uv = clamp(patchCoord.xy, float2(0,0), float2(1,1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
float2 coords = float2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= float2(0.5, 0.5);
int cX = int(round(coords.x));
int cY = int(round(coords.y));
float x = 0.5 - (float(cX) - coords.x);
float y = 0.5 - (float(cY) - coords.y);
dataType d[9];
d[0] = data.read(uint2(cX-1, cY-1), ppack.page);
d[1] = data.read(uint2(cX-1, cY-0), ppack.page);
d[2] = data.read(uint2(cX-1, cY+1), ppack.page);
d[3] = data.read(uint2(cX-0, cY-1), ppack.page);
d[4] = data.read(uint2(cX-0, cY-0), ppack.page);
d[5] = data.read(uint2(cX-0, cY+1), ppack.page);
d[6] = data.read(uint2(cX+1, cY-1), ppack.page);
d[7] = data.read(uint2(cX+1, cY-0), ppack.page);
d[8] = data.read(uint2(cX+1, cY+1), ppack.page);
float3 B, D;
dataType BUCP[3] = {dataType(0), dataType(0), dataType(0)},
DUCP[3] = {dataType(0), dataType(0), dataType(0)};
evalQuadraticBSpline(y, B, D);
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; j++) {
float4 A = d[i*3+j];
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
}
}
evalQuadraticBSpline(x, B, D);
dataType result = dataType(0);
du = dataType(0);
dv = dataType(0);
for (int i = 0; i < 3; ++i) {
result += B[i] * BUCP[i];
du += D[i] * BUCP[i];
dv += B[i] * DUCP[i];
}
du *= ppack.width;
dv *= ppack.height;
return result;
}
// ----------------------------------------------------------------------------
// MipMap Lookups
// ----------------------------------------------------------------------------
template<typename Texture>
auto PtexMipmapLookupNearest(float4 patchCoord,
float level,
Texture data,
device ushort* packings) -> decltype(PtexLookupNearest(patchCoord, int(), data, packings))
{
#if SEAMLESS_MIPMAP
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
const auto result = (1-t) * PtexLookupNearest(patchCoord, levelm, data, packings)
+ t * PtexLookupNearest(patchCoord, levelp, data, packings);
return result;
}
template<typename Texture>
auto PtexMipmapLookup(float4 patchCoord,
float level,
Texture data,
device ushort* packings) -> decltype(PtexLookup(patchCoord, int(), data, packings))
{
#if SEAMLESS_MIPMAP
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
const auto result = (1-t) * PtexLookup(patchCoord, levelm, data, packings)
+ t * PtexLookup(patchCoord, levelp, data, packings);
return result;
}
template<typename Texture>
auto PtexMipmapLookupQuadratic(thread float4& du,
thread float4& dv,
float4 patchCoord,
float level,
Texture data,
device ushort* packings) -> decltype(PtexLookupQuadratic(du, dv, patchCoord, int(), data, packings))
{
using dataType = decltype(PtexLookupQuadratic(du, dv, patchCoord, int(), data, packings));
#if SEAMLESS_MIPMAP
// diff level
int faceID = int(patchCoord.w);
float2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += lerp(lerp(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
lerp(packing.adjSizeDiffs[3], packing.adjSizeDiffs[2], uv.x),
uv.y);
#endif
int levelm = int(floor(level));
int levelp = int(ceil(level));
float t = level - float(levelm);
float4 du0, du1, dv0, dv1;
const auto r0 = PtexLookupQuadratic(du0, dv0, patchCoord, levelm, data, packings);
const auto r1 = PtexLookupQuadratic(du1, dv1, patchCoord, levelp, data, packings);
const auto result = lerp(r0, r1, t);
du = lerp(du0, du1, t);
dv = lerp(dv0, dv1, t);
return result;
}
template<typename Texture>
auto PtexMipmapLookupQuadratic(float4 patchCoord,
float level,
Texture data,
device ushort* packings) -> decltype(data.read(uint2(), int())) //decltype(PtexMipmapLookupQuadratic(float4(), float4(), patchCoord, level, packings)) //Not using the correct decltpye due to the need for thread& types
{
float4 du, dv;
return PtexMipmapLookupQuadratic(du, dv, patchCoord, level, data, packings);
}