Add `etcpak` library for faster ETC/ETC2/S3TC imports.

- `etc` module was renamed to `etcpak` and modified to use the new library.
- PKM importer is removed in the process, it's obsolete.
- Old library `etc2comp` is removed.
- S3TC compression no longer done via `squish` (but decompression still is).
- Slight modifications to etcpak sources for MinGW compatibility,
  to fix LLVM `-Wc++11-narrowing` errors, and to allow using vendored or
  system libpng.

Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>

1 files changed, 0 insertions, 148 deletions

diff --git a/thirdparty/etc2comp/EtcBlock4x4Encoding.h b/thirdparty/etc2comp/EtcBlock4x4Encoding.h
deleted file mode 100644
index c14c3b8616..0000000000
--- a/thirdparty/etc2comp/EtcBlock4x4Encoding.h
+++ /dev/null
@@ -1,148 +0,0 @@
-/*
- * Copyright 2015 The Etc2Comp Authors.
- *
- * 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 "EtcColorFloatRGBA.h"
-
-#include "EtcErrorMetric.h"
-
-#include <assert.h>
-#include <float.h>
-
-namespace Etc
-{
-	class Block4x4;
-
-	// abstract base class for specific encodings
-	class Block4x4Encoding
-	{
-	public:
-
-		static const unsigned int ROWS = 4;
-		static const unsigned int COLUMNS = 4;
-		static const unsigned int PIXELS = ROWS * COLUMNS;
-		static const float LUMA_WEIGHT;
-		static const float CHROMA_BLUE_WEIGHT;
-
-		typedef enum
-		{
-			MODE_UNKNOWN,
-			//
-			MODE_ETC1,
-			MODE_T,
-			MODE_H,
-			MODE_PLANAR,
-			MODE_R11,
-			MODE_RG11,
-			//
-			MODES
-		} Mode;
-
-		Block4x4Encoding(void);
-		//virtual ~Block4x4Encoding(void) =0;
-		virtual ~Block4x4Encoding(void) {}
-		virtual void InitFromSource(Block4x4 *a_pblockParent,
-									ColorFloatRGBA *a_pafrgbaSource,
-
-									unsigned char *a_paucEncodingBits, ErrorMetric a_errormetric) = 0;
-
-		virtual void InitFromEncodingBits(Block4x4 *a_pblockParent,
-											unsigned char *a_paucEncodingBits,
-											ColorFloatRGBA *a_pafrgbaSource,
-
-											ErrorMetric a_errormetric) = 0;
-
-		// perform an iteration of the encoding
-		// the first iteration must generate a complete, valid (if poor) encoding
-		virtual void PerformIteration(float a_fEffort) = 0;
-
-		void CalcBlockError(void);
-
-		inline float GetError(void)
-		{
-			assert(m_fError >= 0.0f);
-
-			return m_fError;
-		}
-
-		inline ColorFloatRGBA * GetDecodedColors(void)
-		{
-			return m_afrgbaDecodedColors;
-		}
-
-		inline float * GetDecodedAlphas(void)
-		{
-			return m_afDecodedAlphas;
-		}
-
-		virtual void SetEncodingBits(void) = 0;
-
-		virtual bool GetFlip(void) = 0;
-
-		virtual bool IsDifferential(void) = 0;
-
-		virtual bool HasSeverelyBentDifferentialColors(void) const = 0;
-
-		inline Mode GetMode(void)
-		{
-			return m_mode;
-		}
-
-		inline bool IsDone(void)
-		{
-			return m_boolDone;
-		}
-
-		inline void SetDoneIfPerfect()
-		{
-			if (GetError() == 0.0f)
-			{
-				m_boolDone = true;
-			}
-		}
-
-		float CalcPixelError(ColorFloatRGBA a_frgbaDecodedColor, float a_fDecodedAlpha,
-								ColorFloatRGBA a_frgbaSourcePixel);
-
-	protected:
-
-		void Init(Block4x4 *a_pblockParent,
-					ColorFloatRGBA *a_pafrgbaSource,
-
-					ErrorMetric a_errormetric);
-
-		Block4x4		*m_pblockParent;
-		ColorFloatRGBA	*m_pafrgbaSource;
-
-		bool			m_boolBorderPixels;				// if block has any border pixels
-
-		ColorFloatRGBA	m_afrgbaDecodedColors[PIXELS];	// decoded RGB components, ignore Alpha
-		float			m_afDecodedAlphas[PIXELS];		// decoded alpha component
-		float			m_fError;						// error for RGBA relative to m_pafrgbaSource
-
-		// intermediate encoding
-		Mode			m_mode;
-
-		unsigned int	m_uiEncodingIterations;
-		bool			m_boolDone;						// all iterations have been done
-		ErrorMetric		m_errormetric;
-
-	private:
-
-	};
-
-} // namespace Etc