gamma.h

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00001 /* === S Y N F I G ========================================================= */
00021 /* ========================================================================= */
00022 
00023 /* === S T A R T =========================================================== */
00024 
00025 #ifndef __SYNFIG_GAMMA_H
00026 #define __SYNFIG_GAMMA_H
00027 
00028 /* === H E A D E R S ======================================================= */
00029 
00030 #include <cmath>
00031 
00032 /* === M A C R O S ========================================================= */
00033 
00034 /* === T Y P E D E F S ===================================================== */
00035 
00036 /* === C L A S S E S & S T R U C T S ======================================= */
00037 
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 }; // END of class Gamma
00103     
00104 }; // END of namespace synfig
00105 
00106 /* === E N D =============================================================== */
00107 
00108 #endif

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