initial commit, 4.5 stable

thirdparty/basis_universal/encoder/basisu_resampler.h

@@ -0,0 +1,198 @@
+// basisu_resampler.h
+// Copyright (C) 2019-2024 Binomial LLC. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#pragma once
+#include "../transcoder/basisu.h"
+
+#define BASISU_RESAMPLER_DEBUG_OPS (0)
+#define BASISU_RESAMPLER_DEFAULT_FILTER "lanczos4"
+#define BASISU_RESAMPLER_MAX_DIMENSION (16384)
+
+namespace basisu
+{
+	// float or double
+	typedef float Resample_Real;
+
+	class Resampler
+	{
+	public:
+		typedef Resample_Real Sample;
+
+		struct Contrib
+		{
+			Resample_Real weight;
+			uint16_t pixel;
+		};
+
+		struct Contrib_List
+		{
+			uint16_t 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 = BASISU_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);
+
+		static void free_clist(Contrib_List* p) { if (p) { free(p->p); free(p); } }
+
+	private:
+		Resampler();
+		Resampler(const Resampler &o);
+		Resampler &operator=(const Resampler &o);
+
+#ifdef BASISU_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;
+		uint8_t *m_Psrc_y_flag;
+
+		// The maximum number of scanlines that can be buffered at one time.
+		enum
+		{
+			MAX_SCAN_BUF_SIZE = BASISU_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 basisu