dds/etc1/pbm/pvr: Make those modules and split thirdparty files

They are not particularly packaged in Linux distros so we do not
facilitate unbundling via SCons. There could be done if/when there
is interest.

Also s/pnm/pbm/, long-lived typo :)

1 files changed, 76 insertions, 0 deletions

diff --git a/thirdparty/rg-etc1/rg_etc1.h b/thirdparty/rg-etc1/rg_etc1.h
new file mode 100644
index 0000000000..9ce89a6cc6
--- /dev/null
+++ b/thirdparty/rg-etc1/rg_etc1.h
@@ -0,0 +1,76 @@
+// File: rg_etc1.h - Fast, high quality ETC1 block packer/unpacker - Rich Geldreich <richgel99@gmail.com>
+// Please see ZLIB license at the end of this file.
+#pragma once
+
+namespace rg_etc1
+{
+   // Unpacks an 8-byte ETC1 compressed block to a block of 4x4 32bpp RGBA pixels.
+   // Returns false if the block is invalid. Invalid blocks will still be unpacked with clamping.
+   // This function is thread safe, and does not dynamically allocate any memory.
+   // If preserve_alpha is true, the alpha channel of the destination pixels will not be overwritten. Otherwise, alpha will be set to 255.
+   bool unpack_etc1_block(const void *pETC1_block, unsigned int* pDst_pixels_rgba, bool preserve_alpha = false);
+
+   // Quality setting = the higher the quality, the slower. 
+   // To pack large textures, it is highly recommended to call pack_etc1_block() in parallel, on different blocks, from multiple threads (particularly when using cHighQuality).
+   enum etc1_quality
+   { 
+      cLowQuality,
+      cMediumQuality,
+      cHighQuality,
+   };
+      
+   struct etc1_pack_params
+   {
+      etc1_quality m_quality;
+      bool m_dithering;
+                              
+      inline etc1_pack_params() 
+      {
+         clear();
+      }
+
+      void clear()
+      {
+         m_quality = cHighQuality;
+         m_dithering = false;
+      }
+   };
+
+   // Important: pack_etc1_block_init() must be called before calling pack_etc1_block().
+   void pack_etc1_block_init();
+
+   // Packs a 4x4 block of 32bpp RGBA pixels to an 8-byte ETC1 block.
+   // 32-bit RGBA pixels must always be arranged as (R,G,B,A) (R first, A last) in memory, independent of platform endianness. A should always be 255.
+   // Returns squared error of result.
+   // This function is thread safe, and does not dynamically allocate any memory.
+   // pack_etc1_block() does not currently support "perceptual" colorspace metrics - it primarily optimizes for RGB RMSE.
+   unsigned int pack_etc1_block(void* pETC1_block, const unsigned int* pSrc_pixels_rgba, etc1_pack_params& pack_params);
+            
+} // namespace rg_etc1
+
+//------------------------------------------------------------------------------
+//
+// rg_etc1 uses the ZLIB license:
+// http://opensource.org/licenses/Zlib
+//
+// Copyright (c) 2012 Rich Geldreich
+//
+// This software is provided 'as-is', without any express or implied
+// warranty.  In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+// claim that you wrote the original software. If you use this software
+// in a product, an acknowledgment in the product documentation would be
+// appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not be
+// misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+//------------------------------------------------------------------------------