44907db895
https://github.com/xonotic/netradiant/pull/1 https://gitlab.com/xonotic/netradiant/-/issues/5 This pull request adds support for Khronos Textures to NetRadiant and Q3Map2, with OpenGL ES 2.0 formats, Ericsson Texture Compression version 1, and BGR/BGRA. The patent-free Ericsson Texture Compression format will be used in the next version of Warsow to significantly reduce VRAM usage on mobile GPUs and the integrated GPU of Intel Broadwell.
115 lines
3.3 KiB
C
115 lines
3.3 KiB
C
// Copyright 2009 Google Inc.
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//
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// Based on the code from Android ETC1Util.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "etclib.h"
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static void ETC_DecodeETC1SubBlock( byte *out, bool outRGBA, int r, int g, int b, int tableIndex, unsigned int low, bool second, bool flipped ){
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int baseX = 0, baseY = 0;
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const int modifierTable[] = {
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2, 8, -2, -8,
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5, 17, -5, -17,
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9, 29, -9, -29,
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13, 42, -13, -42,
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18, 60, -18, -60,
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24, 80, -24, -80,
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33, 106, -33, -106,
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47, 183, -47, -183
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};
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const int *table = modifierTable + tableIndex * 4;
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int i;
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if ( second ) {
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if ( flipped ) {
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baseY = 2;
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}
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else {
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baseX = 2;
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}
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}
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for ( i = 0; i < 8; i++ )
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{
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int x, y, k, delta;
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int qr, qg, qb;
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byte *q;
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if ( flipped ) {
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x = baseX + ( i >> 1 );
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y = baseY + ( i & 1 );
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}
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else {
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x = baseX + ( i >> 2 );
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y = baseY + ( i & 3 );
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}
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k = y + ( x * 4 );
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delta = table[( ( low >> k ) & 1 ) | ( ( low >> ( k + 15 ) ) & 2 )];
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qr = r + delta;
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qg = g + delta;
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qb = b + delta;
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if ( outRGBA ) {
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q = out + 4 * ( x + 4 * y );
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}
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else {
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q = out + 3 * ( x + 4 * y );
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}
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*( q++ ) = ( ( qr > 0 ) ? ( ( qr < 255 ) ? qr : 255 ) : 0 );
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*( q++ ) = ( ( qg > 0 ) ? ( ( qg < 255 ) ? qg : 255 ) : 0 );
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*( q++ ) = ( ( qb > 0 ) ? ( ( qb < 255 ) ? qb : 255 ) : 0 );
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if ( outRGBA ) {
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*( q++ ) = 255;
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}
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}
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}
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void ETC_DecodeETC1Block( const byte* in, byte* out, bool outRGBA ){
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const unsigned int high = ( in[0] << 24 ) | ( in[1] << 16 ) | ( in[2] << 8 ) | in[3];
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const unsigned int low = ( in[4] << 24 ) | ( in[5] << 16 ) | ( in[6] << 8 ) | in[7];
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int r1, r2, g1, g2, b1, b2;
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const bool flipped = ( ( high & 1 ) != 0 );
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if ( high & 2 ) {
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int rBase, gBase, bBase;
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const int lookup[] = { 0, 1, 2, 3, -4, -3, -2, -1 };
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rBase = ( high >> 27 ) & 31;
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r1 = ( rBase << 3 ) | ( rBase >> 2 );
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rBase = ( rBase + ( lookup[( high >> 24 ) & 7] ) ) & 31;
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r2 = ( rBase << 3 ) | ( rBase >> 2 );
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gBase = ( high >> 19 ) & 31;
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g1 = ( gBase << 3 ) | ( gBase >> 2 );
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gBase = ( gBase + ( lookup[( high >> 16 ) & 7] ) ) & 31;
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g2 = ( gBase << 3 ) | ( gBase >> 2 );
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bBase = ( high >> 11 ) & 31;
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b1 = ( bBase << 3 ) | ( bBase >> 2 );
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bBase = ( bBase + ( lookup[( high >> 8 ) & 7] ) ) & 31;
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b2 = ( bBase << 3 ) | ( bBase >> 2 );
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}
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else {
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r1 = ( ( high >> 24 ) & 0xf0 ) | ( ( high >> 28 ) & 0xf );
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r2 = ( ( high >> 20 ) & 0xf0 ) | ( ( high >> 24 ) & 0xf );
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g1 = ( ( high >> 16 ) & 0xf0 ) | ( ( high >> 20 ) & 0xf );
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g2 = ( ( high >> 12 ) & 0xf0 ) | ( ( high >> 16 ) & 0xf );
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b1 = ( ( high >> 8 ) & 0xf0 ) | ( ( high >> 12 ) & 0xf );
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b2 = ( ( high >> 4 ) & 0xf0 ) | ( ( high >> 8 ) & 0xf );
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}
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ETC_DecodeETC1SubBlock( out, outRGBA, r1, g1, b1, ( high >> 5 ) & 7, low, false, flipped );
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ETC_DecodeETC1SubBlock( out, outRGBA, r2, g2, b2, ( high >> 2 ) & 7, low, true, flipped );
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}
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