squish: Clean up patches, add LICENSE.txt

Confirmed that there's no changes in upstream r110 worth including
compared to our r104 tagged version.

thirdparty/README.md

@@ -838,11 +838,13 @@ folder.
 
 Files extracted from upstream source:
 
+- `LICENSE.txt`
 - All `.cpp`, `.h` and `.inl` files
 
-Important: Some files have Godot-made changes.
-They are marked with `// -- GODOT start --` and `// -- GODOT end --`
-comments and a patch is provided in the squish/ folder.
+Some downstream changes have been made and are identified by
+`// -- GODOT begin --` and `// -- GODOT end --` comments.
+They can be reapplied using the patches included in the `patches`
+folder.
 
 
 ## tinyexr

thirdparty/squish/LICENSE.txt

@@ -0,0 +1,20 @@
+Copyright (c) 2006 Simon Brown                          si@sjbrown.co.uk
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

thirdparty/squish/patches/config_sse.patch

@@ -0,0 +1,31 @@
+diff --git a/thirdparty/squish/config.h b/thirdparty/squish/config.h
+index 92edefe966..05f8d72598 100644
+--- a/thirdparty/squish/config.h
++++ b/thirdparty/squish/config.h
+@@ -32,6 +32,26 @@
+ #endif
+
+ // Set to 1 or 2 when building squish to use SSE or SSE2 instructions.
++// -- GODOT start --
++#ifdef _MSC_VER
++  #if defined(_M_IX86_FP)
++    #if _M_IX86_FP >= 2
++      #define SQUISH_USE_SSE 2
++    #elif _M_IX86_FP >= 1
++      #define SQUISH_USE_SSE 1
++    #endif
++  #elif defined(_M_X64)
++    #define SQUISH_USE_SSE 2
++  #endif
++#else
++  #if defined(__SSE2__)
++    #define SQUISH_USE_SSE 2
++  #elif defined(__SSE__)
++    #define SQUISH_USE_SSE 1
++  #endif
++#endif
++// -- GODOT end --
++
+ #ifndef SQUISH_USE_SSE
+ #define SQUISH_USE_SSE 0
+ #endif

thirdparty/squish/patches/decompress_bc4_bc5.patch

@@ -0,0 +1,85 @@
+diff --git a/thirdparty/squish/colourblock.cpp b/thirdparty/squish/colourblock.cpp
+index af8b980365..f14c9362bd 100644
+--- a/thirdparty/squish/colourblock.cpp
++++ b/thirdparty/squish/colourblock.cpp
+@@ -24,6 +24,9 @@
+    -------------------------------------------------------------------------- */
+
+ #include "colourblock.h"
++// -- GODOT start --
++#include "alpha.h"
++// -- GODOT end --
+
+ namespace squish {
+
+@@ -211,4 +214,34 @@ void DecompressColour( u8* rgba, void const* block, bool isDxt1 )
+     }
+ }
+
++// -- GODOT start --
++void DecompressColourBc4( u8* rgba, void const* block)
++{
++    DecompressAlphaDxt5(rgba,block);
++    for ( int i = 0; i < 16; ++i ) {
++        rgba[i*4] = rgba[i*4 + 3];
++		rgba[i*4 + 1] = 0;
++		rgba[i*4 + 2] = 0;
++        rgba[i*4 + 3] = 255;
++    }
++}
++
++void DecompressColourBc5( u8* rgba, void const* block)
++{
++    void const* rblock = block;
++    void const* gblock = reinterpret_cast< u8 const* >( block ) + 8;
++    DecompressAlphaDxt5(rgba,rblock);
++    for ( int i = 0; i < 16; ++i ) {
++        rgba[i*4] = rgba[i*4 + 3];
++    }
++    DecompressAlphaDxt5(rgba,gblock);
++    for ( int i = 0; i < 16; ++i ) {
++        rgba[i*4+1] = rgba[i*4 + 3];
++        rgba[i*4 + 2] = 0;
++        rgba[i*4 + 3] = 255;
++    }
++}
++// -- GODOT end --
++
++
+ } // namespace squish
+diff --git a/thirdparty/squish/colourblock.h b/thirdparty/squish/colourblock.h
+index fee2cd7c5d..e1eb9e4917 100644
+--- a/thirdparty/squish/colourblock.h
++++ b/thirdparty/squish/colourblock.h
+@@ -35,6 +35,10 @@ void WriteColourBlock3( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void*
+ void WriteColourBlock4( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void* block );
+
+ void DecompressColour( u8* rgba, void const* block, bool isDxt1 );
++// -- GODOT start --
++void DecompressColourBc4( u8* rgba, void const* block );
++void DecompressColourBc5( u8* rgba, void const* block );
++// -- GODOT end --
+
+ } // namespace squish
+
+diff --git a/thirdparty/squish/squish.cpp b/thirdparty/squish/squish.cpp
+index 1d22a64ad6..086ba11cd0 100644
+--- a/thirdparty/squish/squish.cpp
++++ b/thirdparty/squish/squish.cpp
+@@ -135,7 +135,15 @@ void Decompress( u8* rgba, void const* block, int flags )
+         colourBlock = reinterpret_cast< u8 const* >( block ) + 8;
+
+     // decompress colour
+-    DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
++    // -- GODOT start --
++    //DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
++    if(( flags & ( kBc4 ) ) != 0)
++        DecompressColourBc4( rgba, colourBlock);
++    else if(( flags & ( kBc5 ) ) != 0)
++        DecompressColourBc5( rgba, colourBlock);
++    else
++        DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
++    // -- GODOT end --
+
+     // decompress alpha separately if necessary
+     if( ( flags & kDxt3 ) != 0 )