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00024 #if defined(_MSC_VER)
00025 #pragma once
00026 #endif
00027
00028 #ifndef PBRT_TEXTURES_MARBLE_H
00029 #define PBRT_TEXTURES_MARBLE_H
00030
00031
00032 #include "pbrt.h"
00033 #include "texture.h"
00034 #include "paramset.h"
00035
00036
00037 class MarbleTexture : public Texture<Spectrum> {
00038 public:
00039
00040 ~MarbleTexture() {
00041 delete mapping;
00042 }
00043 MarbleTexture(int oct, float roughness, float sc, float var,
00044 TextureMapping3D *map)
00045 : octaves(oct), omega(roughness), scale(sc), variation(var),
00046 mapping(map) { }
00047 Spectrum Evaluate(const DifferentialGeometry &dg) const {
00048 Vector dpdx, dpdy;
00049 Point P = mapping->Map(dg, &dpdx, &dpdy);
00050 P *= scale;
00051 float marble = P.y + variation *
00052 FBm(P, scale * dpdx, scale * dpdy, omega, octaves);
00053 float t = .5f + .5f * sinf(marble);
00054
00055 static float c[][3] = { { .58f, .58f, .6f }, { .58f, .58f, .6f }, { .58f, .58f, .6f },
00056 { .5f, .5f, .5f }, { .6f, .59f, .58f }, { .58f, .58f, .6f },
00057 { .58f, .58f, .6f }, {.2f, .2f, .33f }, { .58f, .58f, .6f }, };
00058 #define NC sizeof(c) / sizeof(c[0])
00059 #define NSEG (NC-3)
00060 int first = Floor2Int(t * NSEG);
00061 t = (t * NSEG - first);
00062 Spectrum c0 = Spectrum::FromRGB(c[first]);
00063 Spectrum c1 = Spectrum::FromRGB(c[first+1]);
00064 Spectrum c2 = Spectrum::FromRGB(c[first+2]);
00065 Spectrum c3 = Spectrum::FromRGB(c[first+3]);
00066
00067 Spectrum s0 = (1.f - t) * c0 + t * c1;
00068 Spectrum s1 = (1.f - t) * c1 + t * c2;
00069 Spectrum s2 = (1.f - t) * c2 + t * c3;
00070 s0 = (1.f - t) * s0 + t * s1;
00071 s1 = (1.f - t) * s1 + t * s2;
00072
00073 return 1.5f * ((1.f - t) * s0 + t * s1);
00074 }
00075 private:
00076
00077 int octaves;
00078 float omega, scale, variation;
00079 TextureMapping3D *mapping;
00080 };
00081
00082
00083 Texture<float> *CreateMarbleFloatTexture(const Transform &tex2world,
00084 const TextureParams &tp);
00085 MarbleTexture *CreateMarbleSpectrumTexture(const Transform &tex2world,
00086 const TextureParams &tp);
00087
00088 #endif // PBRT_TEXTURES_MARBLE_H