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//
// 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
//----------------------------------------------------------
struct PtexPacking {
int page;
int nMipmap;
int uOffset;
int vOffset;
int adjSizeDiffs[4];
int width;
int height;
};
PtexPacking getPtexPacking(isamplerBuffer packings, int faceID)
{
PtexPacking packing;
packing.page = texelFetch(packings, faceID*6).x;
packing.nMipmap = texelFetch(packings, faceID*6+1).x;
packing.uOffset = texelFetch(packings, faceID*6+2).x;
packing.vOffset = texelFetch(packings, faceID*6+3).x;
int wh = texelFetch(packings, faceID*6+5).x;
packing.width = 1 << (wh >> 8);
packing.height = 1 << (wh & 0xff);
int adjSizeDiffs = texelFetch(packings, faceID*6+4).x;
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(isamplerBuffer packings, int faceID, int level)
{
PtexPacking packing;
packing.page = texelFetch(packings, faceID*6).x;
packing.nMipmap = texelFetch(packings, faceID*6+1).x;
packing.uOffset = texelFetch(packings, faceID*6+2).x;
packing.vOffset = texelFetch(packings, faceID*6+3).x;
int sizeDiffs = texelFetch(packings, faceID*6+4).x;
int wh = texelFetch(packings, faceID*6+5).x;
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, out float B[3], out float BU[3])
{
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
// ----------------------------------------------------------------------------
vec4 PtexLookupNearest(vec4 patchCoord,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID);
vec2 coords = vec2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return texelFetch(data, ivec3(int(coords.x), int(coords.y), ppack.page), 0);
}
vec4 PtexLookupNearest(vec4 patchCoord,
int level,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
vec2 coords = vec2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
return texelFetch(data, ivec3(int(coords.x), int(coords.y), ppack.page), 0);
}
vec4 PtexLookupFast(vec4 patchCoord,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID);
ivec3 size = textureSize(data, 0);
vec2 coords = vec2((uv.x * ppack.width + ppack.uOffset)/size.x,
(uv.y * ppack.height + ppack.vOffset)/size.y);
return texture(data, vec3(coords.x, coords.y, ppack.page));
}
vec4 PtexLookupFast(vec4 patchCoord,
int level,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
ivec3 size = textureSize(data, 0);
vec2 coords = vec2((uv.x * ppack.width + ppack.uOffset)/size.x,
(uv.y * ppack.height + ppack.vOffset)/size.y);
return texture(data, vec3(coords.x, coords.y, ppack.page));
}
vec4 PtexLookup(vec4 patchCoord,
int level,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
vec2 coords = vec2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= vec2(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);
vec4 d0 = texelFetch(data, ivec3(c0X, c0Y, ppack.page), 0);
vec4 d1 = texelFetch(data, ivec3(c0X, c1Y, ppack.page), 0);
vec4 d2 = texelFetch(data, ivec3(c1X, c0Y, ppack.page), 0);
vec4 d3 = texelFetch(data, ivec3(c1X, c1Y, ppack.page), 0);
vec4 result = (1-t) * ((1-s)*d0 + s*d1) + t * ((1-s)*d2 + s*d3);
return result;
}
vec4 PtexLookupQuadratic(out vec4 du,
out vec4 dv,
vec4 patchCoord,
int level,
sampler2DArray data,
isamplerBuffer packings)
{
vec2 uv = clamp(patchCoord.xy, vec2(0), vec2(1));
int faceID = int(patchCoord.w);
PtexPacking ppack = getPtexPacking(packings, faceID, level);
vec2 coords = vec2(uv.x * ppack.width + ppack.uOffset,
uv.y * ppack.height + ppack.vOffset);
coords -= vec2(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);
vec4 d[9];
d[0] = texelFetch(data, ivec3(cX-1, cY-1, ppack.page), 0);
d[1] = texelFetch(data, ivec3(cX-1, cY-0, ppack.page), 0);
d[2] = texelFetch(data, ivec3(cX-1, cY+1, ppack.page), 0);
d[3] = texelFetch(data, ivec3(cX-0, cY-1, ppack.page), 0);
d[4] = texelFetch(data, ivec3(cX-0, cY-0, ppack.page), 0);
d[5] = texelFetch(data, ivec3(cX-0, cY+1, ppack.page), 0);
d[6] = texelFetch(data, ivec3(cX+1, cY-1, ppack.page), 0);
d[7] = texelFetch(data, ivec3(cX+1, cY-0, ppack.page), 0);
d[8] = texelFetch(data, ivec3(cX+1, cY+1, ppack.page), 0);
float B[3], D[3];
vec4 BUCP[3] = vec4[3](vec4(0,0,0,0), vec4(0,0,0,0), vec4(0,0,0,0)),
DUCP[3] = vec4[3](vec4(0,0,0,0), vec4(0,0,0,0), vec4(0,0,0,0));
evalQuadraticBSpline(y, B, D);
for (int i = 0; i < 3; ++i) {
for (int j = 0; j < 3; j++) {
vec4 A = d[i*3+j];
BUCP[i] += A * B[j];
DUCP[i] += A * D[j];
}
}
evalQuadraticBSpline(x, B, D);
vec4 result = vec4(0);
du = vec4(0);
dv = vec4(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
// ----------------------------------------------------------------------------
vec4 PtexMipmapLookupNearest(vec4 patchCoord,
float level,
sampler2DArray data,
isamplerBuffer packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
vec2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += mix(mix(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
mix(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);
vec4 result = (1-t) * PtexLookupNearest(patchCoord, levelm, data, packings)
+ t * PtexLookupNearest(patchCoord, levelp, data, packings);
return result;
}
vec4 PtexMipmapLookup(vec4 patchCoord,
float level,
sampler2DArray data,
isamplerBuffer packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
vec2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += mix(mix(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
mix(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);
vec4 result = (1-t) * PtexLookup(patchCoord, levelm, data, packings)
+ t * PtexLookup(patchCoord, levelp, data, packings);
return result;
}
vec4 PtexMipmapLookupQuadratic(out vec4 du,
out vec4 dv,
vec4 patchCoord,
float level,
sampler2DArray data,
isamplerBuffer packings)
{
#if defined(SEAMLESS_MIPMAP)
// diff level
int faceID = int(patchCoord.w);
vec2 uv = patchCoord.xy;
PtexPacking packing = getPtexPacking(packings, faceID);
level += mix(mix(packing.adjSizeDiffs[0], packing.adjSizeDiffs[1], uv.x),
mix(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);
vec4 du0, du1, dv0, dv1;
vec4 r0 = PtexLookupQuadratic(du0, dv0, patchCoord, levelm, data, packings);
vec4 r1 = PtexLookupQuadratic(du1, dv1, patchCoord, levelp, data, packings);
vec4 result = mix(r0, r1, t);
du = mix(du0, du1, t);
dv = mix(dv0, dv1, t);
return result;
}
vec4 PtexMipmapLookupQuadratic(vec4 patchCoord,
float level,
sampler2DArray data,
isamplerBuffer packings)
{
vec4 du, dv;
return PtexMipmapLookupQuadratic(du, dv, patchCoord, level, data, packings);
}
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