2011-12-27 21:18:07 +00:00
commit 9f98ea7e22
192 changed files with 77747 additions and 0 deletions
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+// File: crn_resampler.h
+// RG: This is public domain code, originally derived from Graphics Gems 3, see: http://code.google.com/p/imageresampler/
+#pragma once
+
+namespace crnlib
+{
+   #define CRNLIB_RESAMPLER_DEBUG_OPS 0
+   #define CRNLIB_RESAMPLER_DEFAULT_FILTER "lanczos4"
+
+   #define CRNLIB_RESAMPLER_MAX_DIMENSION 16384
+
+   // float or double
+   typedef float Resample_Real;
+
+   class Resampler
+   {
+   public:
+      typedef Resample_Real Sample;
+
+      struct Contrib
+      {
+         Resample_Real weight;
+         unsigned short pixel;
+      };
+
+      struct Contrib_List
+      {
+         unsigned short n;
+         Contrib* p;
+      };
+
+      enum Boundary_Op
+      {
+         BOUNDARY_WRAP = 0,
+         BOUNDARY_REFLECT = 1,
+         BOUNDARY_CLAMP = 2
+      };
+
+      enum Status
+      {
+         STATUS_OKAY = 0,
+         STATUS_OUT_OF_MEMORY = 1,
+         STATUS_BAD_FILTER_NAME = 2,
+         STATUS_SCAN_BUFFER_FULL = 3
+      };
+      
+      // src_x/src_y - Input dimensions
+      // dst_x/dst_y - Output dimensions
+      // boundary_op - How to sample pixels near the image boundaries
+      // sample_low/sample_high - Clamp output samples to specified range, or disable clamping if sample_low >= sample_high
+      // Pclist_x/Pclist_y - Optional pointers to contributor lists from another instance of a Resampler
+      // src_x_ofs/src_y_ofs - Offset input image by specified amount (fractional values okay)
+      Resampler(
+         int src_x, int src_y,
+         int dst_x, int dst_y,
+         Boundary_Op boundary_op = BOUNDARY_CLAMP,
+         Resample_Real sample_low = 0.0f, Resample_Real sample_high = 0.0f,		
+         const char* Pfilter_name = CRNLIB_RESAMPLER_DEFAULT_FILTER,
+         Contrib_List* Pclist_x = NULL,
+         Contrib_List* Pclist_y = NULL,
+         Resample_Real filter_x_scale = 1.0f,
+         Resample_Real filter_y_scale = 1.0f,
+         Resample_Real src_x_ofs = 0.0f, 
+         Resample_Real src_y_ofs = 0.0f);
+
+      ~Resampler();
+
+      // Reinits resampler so it can handle another frame.
+      void restart();
+
+      // false on out of memory.
+      bool put_line(const Sample* Psrc);
+
+      // NULL if no scanlines are currently available (give the resampler more scanlines!)
+      const Sample* get_line();
+
+      Status status() const { return m_status; }
+
+      // Returned contributor lists can be shared with another Resampler. 
+      void get_clists(Contrib_List** ptr_clist_x, Contrib_List** ptr_clist_y);
+      Contrib_List* get_clist_x() const {	return m_Pclist_x; }
+      Contrib_List* get_clist_y() const {	return m_Pclist_y; }
+
+      // Filter accessors.
+      static int get_filter_num();
+      static const char* get_filter_name(int filter_num);
+      
+      static Contrib_List* make_clist(
+         int src_x, int dst_x, Boundary_Op boundary_op,
+         Resample_Real (*Pfilter)(Resample_Real),
+         Resample_Real filter_support,
+         Resample_Real filter_scale,
+         Resample_Real src_ofs);
+      
+   private:
+      Resampler();
+      Resampler(const Resampler& o);
+      Resampler& operator= (const Resampler& o);
+
+   #ifdef CRNLIB_RESAMPLER_DEBUG_OPS
+      int total_ops;
+   #endif
+
+      int m_intermediate_x;
+
+      int m_resample_src_x;
+      int m_resample_src_y;
+      int m_resample_dst_x;
+      int m_resample_dst_y;
+
+      Boundary_Op m_boundary_op;
+
+      Sample* m_Pdst_buf;
+      Sample* m_Ptmp_buf;
+
+      Contrib_List* m_Pclist_x;
+      Contrib_List* m_Pclist_y;
+
+      bool m_clist_x_forced;
+      bool m_clist_y_forced;
+
+      bool m_delay_x_resample;
+
+      int* m_Psrc_y_count;
+      unsigned char* m_Psrc_y_flag;
+
+      // The maximum number of scanlines that can be buffered at one time.
+      enum { MAX_SCAN_BUF_SIZE = CRNLIB_RESAMPLER_MAX_DIMENSION };
+      
+      struct Scan_Buf
+      {
+         int scan_buf_y[MAX_SCAN_BUF_SIZE];
+         Sample* scan_buf_l[MAX_SCAN_BUF_SIZE];
+      };
+
+      Scan_Buf* m_Pscan_buf;
+
+      int m_cur_src_y;
+      int m_cur_dst_y;
+
+      Status m_status;
+
+      void resample_x(Sample* Pdst, const Sample* Psrc);
+      void scale_y_mov(Sample* Ptmp, const Sample* Psrc, Resample_Real weight, int dst_x);
+      void scale_y_add(Sample* Ptmp, const Sample* Psrc, Resample_Real weight, int dst_x);
+      void clamp(Sample* Pdst, int n);
+      void resample_y(Sample* Pdst);
+
+      static int reflect(const int j, const int src_x, const Boundary_Op boundary_op);
+      
+      inline int count_ops(Contrib_List* Pclist, int k)
+      {
+         int i, t = 0;
+         for (i = 0; i < k; i++)
+            t += Pclist[i].n;
+         return (t);
+      }
+
+      Resample_Real m_lo;
+      Resample_Real m_hi;
+
+      inline Resample_Real clamp_sample(Resample_Real f) const
+      {
+         if (f < m_lo)
+            f = m_lo;
+         else if (f > m_hi)
+            f = m_hi;
+         return f;
+      }   
+   };
+
+} // namespace crnlib
+