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00025 #ifndef __SYNFIG_GAMMA_H
00026 #define __SYNFIG_GAMMA_H
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00030 #include <cmath>
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00038 namespace synfig {
00039
00044 class Gamma
00045 {
00046 float gamma_r;
00047 float gamma_g;
00048 float gamma_b;
00049 float black_level;
00050 float red_blue_level;
00051
00052 unsigned char table_r_U16_to_U8[65536];
00053 unsigned char table_g_U16_to_U8[65536];
00054 unsigned char table_b_U16_to_U8[65536];
00055
00056 float table_r_U8_to_F32[256];
00057 float table_g_U8_to_F32[256];
00058 float table_b_U8_to_F32[256];
00059
00060 public:
00061 Gamma(float x=1):black_level(0) { set_gamma(x); }
00062
00063 void set_gamma(float x);
00064 void set_gamma_r(float x);
00065 void set_gamma_g(float x);
00066 void set_gamma_b(float x);
00067 void set_black_level(float x);
00068
00069 void set_red_blue_level(float x);
00070 void set_all(float r, float g, float b, float black, float red_blue=1.0f);
00071
00072 float get_gamma()const { return (gamma_r+gamma_g+gamma_b)*0.33333333; }
00073 float get_gamma_r()const { return gamma_r; }
00074 float get_gamma_g()const { return gamma_g; }
00075 float get_gamma_b()const { return gamma_b; }
00076 float get_black_level()const { return black_level; }
00077 float get_red_blue_level()const { return red_blue_level; }
00078
00079 void refresh_gamma_r();
00080 void refresh_gamma_g();
00081 void refresh_gamma_b();
00082
00083 const unsigned char &r_U16_to_U8(int i)const { return table_r_U16_to_U8[i]; }
00084 const unsigned char &g_U16_to_U8(int i)const { return table_g_U16_to_U8[i]; }
00085 const unsigned char &b_U16_to_U8(int i)const { return table_b_U16_to_U8[i]; }
00086
00087 const unsigned char &r_F32_to_U8(float x)const { return table_r_U16_to_U8[(int)(x*65535.0f)]; }
00088 const unsigned char &g_F32_to_U8(float x)const { return table_g_U16_to_U8[(int)(x*65535.0f)]; }
00089 const unsigned char &b_F32_to_U8(float x)const { return table_b_U16_to_U8[(int)(x*65535.0f)]; }
00090
00091 unsigned short r_F32_to_U16(float x)const { return (unsigned short)table_r_U16_to_U8[(int)(x*65535.0f)]<<8; }
00092 unsigned short g_F32_to_U16(float x)const { return (unsigned short)table_g_U16_to_U8[(int)(x*65535.0f)]<<8; }
00093 unsigned short b_F32_to_U16(float x)const { return (unsigned short)table_b_U16_to_U8[(int)(x*65535.0f)]<<8; }
00094
00095 const float& r_U8_to_F32(int i)const { return table_r_U8_to_F32[i]; }
00096 const float& g_U8_to_F32(int i)const { return table_g_U8_to_F32[i]; }
00097 const float& b_U8_to_F32(int i)const { return table_b_U8_to_F32[i]; }
00098
00099 float r_F32_to_F32(float x)const { return static_cast<float>(pow(x,gamma_r)*(1.0f-black_level)+black_level); }
00100 float g_F32_to_F32(float x)const { return static_cast<float>(pow(x,gamma_g)*(1.0f-black_level)+black_level); }
00101 float b_F32_to_F32(float x)const { return static_cast<float>(pow(x,gamma_b)*(1.0f-black_level)+black_level); }
00102 };
00103
00104 };
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00108 #endif