# HG changeset patch
# User Wolfgang Lieff <>
# Date 1523032983 -3600
# Node ID 1618f87e1ae8a6aa0a7fa22890ffd353ab961f55
# Parent  fa71e9331b534c4b70b22add9fba882f4e0361f7
Additional loader for DDS file format

diff -r fa71e9331b53 -r 1618f87e1ae8 doc/docbook/GuideReferenceSupportedFormats.xml
--- a/doc/docbook/GuideReferenceSupportedFormats.xml	Tue Apr 03 13:08:34 2018 +0100
+++ b/doc/docbook/GuideReferenceSupportedFormats.xml	Fri Apr 06 17:43:03 2018 +0100
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <section id="GuideReferenceSupportedFormats">
   <title id="titleGuideReferenceSupportedFormats">Supported File Formats</title>
-  <para>3FR, ANI, APM, ARW, BMP, CR2, CRW, CUR, DNG, ERF, GIF, ICNS, ICO, JPE/JPEG/JPG, JPS, KDC, MEF, MPO, MOS, MRW, NEF, ORF, PEF, PTX, PBM/PGM/PNM/PPM, PNG, QIF/QTIF (QuickTime Image Format), RAF, RAW, RW2, SR2, SRF, SVG/SVGZ, TGA/TARGA, TIF/TIFF, WMF, XBM, XPM. Animated GIFs are supported.</para>
+  <para>3FR, ANI, APM, ARW, BMP, CR2, CRW, CUR, DDS, DNG, ERF, GIF, ICNS, ICO, JPE/JPEG/JPG, JPS, KDC, MEF, MPO, MOS, MRW, NEF, ORF, PEF, PTX, PBM/PGM/PNM/PPM, PNG, QIF/QTIF (QuickTime Image Format), RAF, RAW, RW2, SR2, SRF, SVG/SVGZ, TGA/TARGA, TIF/TIFF, WMF, XBM, XPM. Animated GIFs are supported.</para>
   <para>
     Refer to
     <link linkend="GuideReferencePixbufLoaders" endterm="titleGuideReferencePixbufLoaders" />
diff -r fa71e9331b53 -r 1618f87e1ae8 src/Makefile.am
--- a/src/Makefile.am	Tue Apr 03 13:08:34 2018 +0100
+++ b/src/Makefile.am	Fri Apr 06 17:43:03 2018 +0100
@@ -179,6 +179,8 @@
 	image_load_jpeg.h\
 	image_load_tiff.c\
 	image_load_tiff.h\
+	image_load_dds.c\
+	image_load_dds.h\
 	image_load_ffmpegthumbnailer.c\
 	image_load_ffmpegthumbnailer.h\
 	image-overlay.c	\
diff -r fa71e9331b53 -r 1618f87e1ae8 src/editors.c
--- a/src/editors.c	Tue Apr 03 13:08:34 2018 +0100
+++ b/src/editors.c	Fri Apr 06 17:43:03 2018 +0100
@@ -119,6 +119,7 @@
 		{"image/svg+xml",	".svg"},
 		{"image/svg+xml-compressed", 	".svg"},
 		{"image/tiff",		".tiff;.tif;.mef"},
+		{"image/vnd-ms.dds",	".dds"},
 		{"image/x-adobe-dng",	".dng"},
 		{"image/x-bmp",		".bmp"},
 		{"image/x-canon-crw",	".crw"},
diff -r fa71e9331b53 -r 1618f87e1ae8 src/filefilter.c
--- a/src/filefilter.c	Tue Apr 03 13:08:34 2018 +0100
+++ b/src/filefilter.c	Fri Apr 06 17:43:03 2018 +0100
@@ -288,6 +288,9 @@
 	filter_add_if_missing("mkv", "Matroska video file", ".mkv;.webm", FORMAT_CLASS_VIDEO, FALSE, FALSE, FALSE);
 	filter_add_if_missing("wmv", "Windows Media Video file", ".wmv;.asf", FORMAT_CLASS_VIDEO, FALSE, FALSE, FALSE);
 	filter_add_if_missing("flv", "Flash Video file", ".flv", FORMAT_CLASS_VIDEO, FALSE, FALSE, FALSE);
+
+	/* other supported formats */
+	filter_add_if_missing("dds", "DirectDraw Surface", ".dds", FORMAT_CLASS_IMAGE, FALSE, FALSE, TRUE);
 }
 
 GList *filter_to_list(const gchar *extensions)
diff -r fa71e9331b53 -r 1618f87e1ae8 src/image-load.c
--- a/src/image-load.c	Tue Apr 03 13:08:34 2018 +0100
+++ b/src/image-load.c	Fri Apr 06 17:43:03 2018 +0100
@@ -24,6 +24,7 @@
 #include "image_load_gdk.h"
 #include "image_load_jpeg.h"
 #include "image_load_tiff.h"
+#include "image_load_dds.h"
 #include "image_load_ffmpegthumbnailer.h"
 
 #include "exif.h"
@@ -636,6 +637,12 @@
 		}
 	else
 #endif
+	if (il->bytes_total >= 3 && il->mapped_file[0] == 0x44 && il->mapped_file[1] == 0x44 && il->mapped_file[2] == 0x53)
+		{
+		DEBUG_1("Using dds loader");
+		image_loader_backend_set_dds(&il->backend);
+		}
+	else
 		image_loader_backend_set_default(&il->backend);
 
 	il->loader = il->backend.loader_new(image_loader_area_updated_cb, image_loader_size_cb, image_loader_area_prepared_cb, il);
diff -r fa71e9331b53 -r 1618f87e1ae8 src/image_load_dds.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/image_load_dds.c	Fri Apr 06 17:43:03 2018 +0100
@@ -0,0 +1,613 @@
+/*
+ * Copyright (C) 2018 The Geeqie Team
+ *
+ * Author: Wolfgang Lieff
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+ * Derived from dds_reader written by:
+ * Copyright (c) 2015 Kenji Sasaki
+ * Released under the MIT license.
+ * https://github.com/npedotnet/DDSReader/blob/master/LICENSE
+
+ */
+
+#include "main.h"
+
+#include "image-load.h"
+#include "image_load_dds.h"
+
+typedef struct _ImageLoaderDDS ImageLoaderDDS;
+struct _ImageLoaderDDS {
+	ImageLoaderBackendCbAreaUpdated area_updated_cb;
+	ImageLoaderBackendCbSize size_cb;
+	ImageLoaderBackendCbAreaPrepared area_prepared_cb;
+	gpointer data;
+	GdkPixbuf *pixbuf;
+	guint requested_width;
+	guint requested_height;
+	gboolean abort;
+};
+
+static void free_buffer(guchar *pixels, gpointer data)
+{
+	g_free(pixels);
+}
+
+int ddsGetHeight(unsigned const char * buffer) {
+	return (buffer[12] & 0xFF) | (buffer[13] & 0xFF) << 8 | (buffer[14] & 0xFF) << 16 | (buffer[15] & 0xFF) << 24;
+}
+
+int ddsGetWidth(unsigned const char * buffer) {
+	return (buffer[16] & 0xFF) | (buffer[17] & 0xFF) << 8 | (buffer[18] & 0xFF) << 16 | (buffer[19] & 0xFF) << 24;
+}
+
+int ddsGetMipmap(unsigned const char * buffer) {
+	return (buffer[28] & 0xFF) | (buffer[29] & 0xFF) << 8 | (buffer[30] & 0xFF) << 16 | (buffer[31] & 0xFF) << 24;
+}
+
+int ddsGetPixelFormatFlags(unsigned const char * buffer) {
+	return (buffer[80] & 0xFF) | (buffer[81] & 0xFF) << 8 | (buffer[82] & 0xFF) << 16 | (buffer[83] & 0xFF) << 24;
+}
+
+int ddsGetFourCC(unsigned const char * buffer) {
+	return (buffer[84] & 0xFF) << 24 | (buffer[85] & 0xFF) << 16 | (buffer[86] & 0xFF) << 8 | (buffer[87] & 0xFF);
+}
+
+int ddsGetBitCount(unsigned const char * buffer) {
+	return (buffer[88] & 0xFF) | (buffer[89] & 0xFF) << 8 | (buffer[90] & 0xFF) << 16 | (buffer[91] & 0xFF) << 24;
+}
+
+int ddsGetRedMask(unsigned const char * buffer) {
+	return (buffer[92] & 0xFF) | (buffer[93] & 0xFF) << 8 | (buffer[94] & 0xFF) << 16 | (buffer[95] & 0xFF) << 24;
+}
+
+int ddsGetGreenMask(unsigned const char * buffer) {
+	return (buffer[96] & 0xFF) | (buffer[97] & 0xFF) << 8 | (buffer[98] & 0xFF) << 16 | (buffer[99] & 0xFF) << 24;
+}
+
+int ddsGetBlueMask(unsigned const char * buffer) {
+	return (buffer[100] & 0xFF) | (buffer[101] & 0xFF) << 8 | (buffer[102] & 0xFF) << 16 | (buffer[103] & 0xFF) << 24;
+}
+
+int ddsGetAlphaMask(unsigned const char * buffer) {
+	return (buffer[104] & 0xFF) | (buffer[105] & 0xFF) << 8 | (buffer[106] & 0xFF) << 16 | (buffer[107] & 0xFF) << 24;
+}
+
+// Image Type
+#define DXT1 (0x44585431)
+#define DXT2 (0x44585432)
+#define DXT3 (0x44585433)
+#define DXT4 (0x44585434)
+#define DXT5 (0x44585435)
+#define A1R5G5B5 ((1 << 16) | 2)
+#define X1R5G5B5 ((2 << 16) | 2)
+#define A4R4G4B4 ((3 << 16) | 2)
+#define X4R4G4B4 ((4 << 16) | 2)
+#define R5G6B5 ((5 << 16) | 2)
+#define R8G8B8 ((1 << 16) | 3)
+#define A8B8G8R8 ((1 << 16) | 4)
+#define X8B8G8R8 ((2 << 16) | 4)
+#define A8R8G8B8 ((3 << 16) | 4)
+#define X8R8G8B8 ((4 << 16) | 4)
+
+// RGBA Masks
+static const int A1R5G5B5_MASKS[] = { 0x7C00, 0x03E0, 0x001F, 0x8000 };
+static const int X1R5G5B5_MASKS[] = { 0x7C00, 0x03E0, 0x001F, 0x0000 };
+static const int A4R4G4B4_MASKS[] = { 0x0F00, 0x00F0, 0x000F, 0xF000 };
+static const int X4R4G4B4_MASKS[] = { 0x0F00, 0x00F0, 0x000F, 0x0000 };
+static const int R5G6B5_MASKS[] = { 0xF800, 0x07E0, 0x001F, 0x0000 };
+static const int R8G8B8_MASKS[] = { 0xFF0000, 0x00FF00, 0x0000FF, 0x000000 };
+static const int A8B8G8R8_MASKS[] = { 0x000000FF, 0x0000FF00, 0x00FF0000, 0xFF000000 };
+static const int X8B8G8R8_MASKS[] = { 0x000000FF, 0x0000FF00, 0x00FF0000, 0x00000000 };
+static const int A8R8G8B8_MASKS[] = { 0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000 };
+static const int X8R8G8B8_MASKS[] = { 0x00FF0000, 0x0000FF00, 0x000000FF, 0x00000000 };
+
+// BIT4 = 17 * index;
+static const int BIT5[] = { 0, 8, 16, 25, 33, 41, 49, 58, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, 197, 206, 214, 222, 230, 239, 247, 255 };
+static const int BIT6[] = { 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142, 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255 };
+
+static int ddsGetType(const unsigned char *buffer) {
+	int type = 0;
+	int flags = ddsGetPixelFormatFlags(buffer);
+	if ((flags & 0x04) != 0) {
+		// DXT
+		type = ddsGetFourCC(buffer);
+	}
+	else if ((flags & 0x40) != 0) {
+		// RGB
+		int bitCount = ddsGetBitCount(buffer);
+		int redMask = ddsGetRedMask(buffer);
+		int greenMask = ddsGetGreenMask(buffer);
+		int blueMask = ddsGetBlueMask(buffer);
+		int alphaMask = ((flags & 0x01) != 0) ? ddsGetAlphaMask(buffer) : 0; // 0x01 alpha
+		if (bitCount == 16) {
+			if (redMask == A1R5G5B5_MASKS[0] && greenMask == A1R5G5B5_MASKS[1] && blueMask == A1R5G5B5_MASKS[2] && alphaMask == A1R5G5B5_MASKS[3]) {
+				// A1R5G5B5
+				type = A1R5G5B5;
+			}
+			else if (redMask == X1R5G5B5_MASKS[0] && greenMask == X1R5G5B5_MASKS[1] && blueMask == X1R5G5B5_MASKS[2] && alphaMask == X1R5G5B5_MASKS[3]) {
+				// X1R5G5B5
+				type = X1R5G5B5;
+			}
+			else if (redMask == A4R4G4B4_MASKS[0] && greenMask == A4R4G4B4_MASKS[1] && blueMask == A4R4G4B4_MASKS[2] && alphaMask == A4R4G4B4_MASKS[3]) {
+				// A4R4G4B4
+				type = A4R4G4B4;
+			}
+			else if (redMask == X4R4G4B4_MASKS[0] && greenMask == X4R4G4B4_MASKS[1] && blueMask == X4R4G4B4_MASKS[2] && alphaMask == X4R4G4B4_MASKS[3]) {
+				// X4R4G4B4
+				type = X4R4G4B4;
+			}
+			else if (redMask == R5G6B5_MASKS[0] && greenMask == R5G6B5_MASKS[1] && blueMask == R5G6B5_MASKS[2] && alphaMask == R5G6B5_MASKS[3]) {
+				// R5G6B5
+				type = R5G6B5;
+			}
+			else {
+				// Unsupported 16bit RGB image
+			}
+		}
+		else if (bitCount == 24) {
+			if (redMask == R8G8B8_MASKS[0] && greenMask == R8G8B8_MASKS[1] && blueMask == R8G8B8_MASKS[2] && alphaMask == R8G8B8_MASKS[3]) {
+				// R8G8B8
+				type = R8G8B8;
+			}
+			else {
+				// Unsupported 24bit RGB image
+			}
+		}
+		else if (bitCount == 32) {
+			if (redMask == A8B8G8R8_MASKS[0] && greenMask == A8B8G8R8_MASKS[1] && blueMask == A8B8G8R8_MASKS[2] && alphaMask == A8B8G8R8_MASKS[3]) {
+				// A8B8G8R8
+				type = A8B8G8R8;
+			}
+			else if (redMask == X8B8G8R8_MASKS[0] && greenMask == X8B8G8R8_MASKS[1] && blueMask == X8B8G8R8_MASKS[2] && alphaMask == X8B8G8R8_MASKS[3]) {
+				// X8B8G8R8
+				type = X8B8G8R8;
+			}
+			else if (redMask == A8R8G8B8_MASKS[0] && greenMask == A8R8G8B8_MASKS[1] && blueMask == A8R8G8B8_MASKS[2] && alphaMask == A8R8G8B8_MASKS[3]) {
+				// A8R8G8B8
+				type = A8R8G8B8;
+			}
+			else if (redMask == X8R8G8B8_MASKS[0] && greenMask == X8R8G8B8_MASKS[1] && blueMask == X8R8G8B8_MASKS[2] && alphaMask == X8R8G8B8_MASKS[3]) {
+				// X8R8G8B8
+				type = X8R8G8B8;
+			}
+			else {
+				// Unsupported 32bit RGB image
+			}
+		}
+	}
+	else {
+		// YUV or LUMINANCE image
+	}
+	return type;
+}
+
+int ddsGetDXTColor2_1(int c0, int c1, int a) {
+	// 2*c0/3 + c1/3
+	int r = (2 * BIT5[(c0 & 0xFC00) >> 11] + BIT5[(c1 & 0xFC00) >> 11]) / 3;
+	int g = (2 * BIT6[(c0 & 0x07E0) >> 5] + BIT6[(c1 & 0x07E0) >> 5]) / 3;
+	int b = (2 * BIT5[c0 & 0x001F] + BIT5[c1 & 0x001F]) / 3;
+	return (a << 24) | (r << 0) | (g << 8) | (b << 16);
+}
+
+int ddsGetDXTColor1_1(int c0, int c1, int a) {
+	// (c0+c1) / 2
+	int r = (BIT5[(c0 & 0xFC00) >> 11] + BIT5[(c1 & 0xFC00) >> 11]) / 2;
+	int g = (BIT6[(c0 & 0x07E0) >> 5] + BIT6[(c1 & 0x07E0) >> 5]) / 2;
+	int b = (BIT5[c0 & 0x001F] + BIT5[c1 & 0x001F]) / 2;
+	return (a << 24) | (r << 0) | (g << 8) | (b << 16);
+}
+
+int ddsGetDXTColor1(int c, int a) {
+	int r = BIT5[(c & 0xFC00) >> 11];
+	int g = BIT6[(c & 0x07E0) >> 5];
+	int b = BIT5[(c & 0x001F)];
+	return (a << 24) | (r << 0) | (g << 8) | (b << 16);
+}
+
+int ddsGetDXTColor(int c0, int c1, int a, int t) {
+	switch (t) {
+	case 0: return ddsGetDXTColor1(c0, a);
+	case 1: return ddsGetDXTColor1(c1, a);
+	case 2: return (c0 > c1) ? ddsGetDXTColor2_1(c0, c1, a) : ddsGetDXTColor1_1(c0, c1, a);
+	case 3: return (c0 > c1) ? ddsGetDXTColor2_1(c1, c0, a) : 0;
+	}
+	return 0;
+}
+
+guchar *ddsDecodeDXT1(int width, int height, const unsigned char *buffer) {
+	int *pixels = g_try_malloc(4 * width*height);
+	int index = 128;
+	int w = (width + 3) / 4;
+	int h = (height + 3) / 4;
+	for (int i = 0; i<h; i++) {
+		for (int j = 0; j<w; j++) {
+			int c0 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			int c1 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			for (int k = 0; k<4; k++) {
+				if (4 * i + k >= height) break;
+				int t0 = (buffer[index] & 0x03);
+				int t1 = (buffer[index] & 0x0C) >> 2;
+				int t2 = (buffer[index] & 0x30) >> 4;
+				int t3 = (buffer[index++] & 0xC0) >> 6;
+				pixels[4 * width*i + 4 * j + width*k + 0] = ddsGetDXTColor(c0, c1, 0xFF, t0);
+				if (4 * j + 1 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 1] = ddsGetDXTColor(c0, c1, 0xFF, t1);
+				if (4 * j + 2 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 2] = ddsGetDXTColor(c0, c1, 0xFF, t2);
+				if (4 * j + 3 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 3] = ddsGetDXTColor(c0, c1, 0xFF, t3);
+			}
+		}
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsDecodeDXT3(int width, int height, const unsigned char *buffer) {
+	int *pixels = g_try_malloc(4 * width*height);
+	int index = 128;
+	int w = (width + 3) / 4;
+	int h = (height + 3) / 4;
+	int alphaTable[16];
+	for (int i = 0; i<h; i++) {
+		for (int j = 0; j<w; j++) {
+			// create alpha table(4bit to 8bit)
+			for (int k = 0; k<4; k++) {
+				int a0 = (buffer[index++] & 0xFF);
+				int a1 = (buffer[index++] & 0xFF);
+				// 4bit alpha to 8bit alpha
+				alphaTable[4 * k + 0] = 17 * ((a0 & 0xF0) >> 4);
+				alphaTable[4 * k + 1] = 17 * (a0 & 0x0F);
+				alphaTable[4 * k + 2] = 17 * ((a1 & 0xF0) >> 4);
+				alphaTable[4 * k + 3] = 17 * (a1 & 0x0F);
+			}
+			int c0 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			int c1 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			for (int k = 0; k<4; k++) {
+				if (4 * i + k >= height) break;
+				int t0 = (buffer[index] & 0x03);
+				int t1 = (buffer[index] & 0x0C) >> 2;
+				int t2 = (buffer[index] & 0x30) >> 4;
+				int t3 = (buffer[index++] & 0xC0) >> 6;
+				pixels[4 * width*i + 4 * j + width*k + 0] = ddsGetDXTColor(c0, c1, alphaTable[4 * k + 0], t0);
+				if (4 * j + 1 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 1] = ddsGetDXTColor(c0, c1, alphaTable[4 * k + 1], t1);
+				if (4 * j + 2 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 2] = ddsGetDXTColor(c0, c1, alphaTable[4 * k + 2], t2);
+				if (4 * j + 3 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 3] = ddsGetDXTColor(c0, c1, alphaTable[4 * k + 3], t3);
+			}
+		}
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsDecodeDXT2(int width, int height, const unsigned char *buffer) {
+	return ddsDecodeDXT3(width, height, buffer);
+}
+
+int ddsGetDXT5Alpha(int a0, int a1, int t) {
+	if (a0 > a1) switch (t) {
+	case 0: return a0;
+	case 1: return a1;
+	case 2: return (6 * a0 + a1) / 7;
+	case 3: return (5 * a0 + 2 * a1) / 7;
+	case 4: return (4 * a0 + 3 * a1) / 7;
+	case 5: return (3 * a0 + 4 * a1) / 7;
+	case 6: return (2 * a0 + 5 * a1) / 7;
+	case 7: return (a0 + 6 * a1) / 7;
+	}
+	else switch (t) {
+	case 0: return a0;
+	case 1: return a1;
+	case 2: return (4 * a0 + a1) / 5;
+	case 3: return (3 * a0 + 2 * a1) / 5;
+	case 4: return (2 * a0 + 3 * a1) / 5;
+	case 5: return (a0 + 4 * a1) / 5;
+	case 6: return 0;
+	case 7: return 255;
+	}
+	return 0;
+}
+
+guchar *ddsDecodeDXT5(int width, int height, const unsigned char *buffer) {
+	int *pixels = g_try_malloc(4 * width*height);
+	int index = 128;
+	int w = (width + 3) / 4;
+	int h = (height + 3) / 4;
+	int alphaTable[16];
+	for (int i = 0; i<h; i++) {
+		for (int j = 0; j<w; j++) {
+			// create alpha table
+			int a0 = (buffer[index++] & 0xFF);
+			int a1 = (buffer[index++] & 0xFF);
+			int b0 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8 | (buffer[index + 2] & 0xFF) << 16; index += 3;
+			int b1 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8 | (buffer[index + 2] & 0xFF) << 16; index += 3;
+			alphaTable[0] = b0 & 0x07;
+			alphaTable[1] = (b0 >> 3) & 0x07;
+			alphaTable[2] = (b0 >> 6) & 0x07;
+			alphaTable[3] = (b0 >> 9) & 0x07;
+			alphaTable[4] = (b0 >> 12) & 0x07;
+			alphaTable[5] = (b0 >> 15) & 0x07;
+			alphaTable[6] = (b0 >> 18) & 0x07;
+			alphaTable[7] = (b0 >> 21) & 0x07;
+			alphaTable[8] = b1 & 0x07;
+			alphaTable[9] = (b1 >> 3) & 0x07;
+			alphaTable[10] = (b1 >> 6) & 0x07;
+			alphaTable[11] = (b1 >> 9) & 0x07;
+			alphaTable[12] = (b1 >> 12) & 0x07;
+			alphaTable[13] = (b1 >> 15) & 0x07;
+			alphaTable[14] = (b1 >> 18) & 0x07;
+			alphaTable[15] = (b1 >> 21) & 0x07;
+			int c0 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			int c1 = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+			for (int k = 0; k<4; k++) {
+				if (4 * i + k >= height) break;
+				int t0 = (buffer[index] & 0x03);
+				int t1 = (buffer[index] & 0x0C) >> 2;
+				int t2 = (buffer[index] & 0x30) >> 4;
+				int t3 = (buffer[index++] & 0xC0) >> 6;
+				pixels[4 * width*i + 4 * j + width*k + 0] = ddsGetDXTColor(c0, c1, ddsGetDXT5Alpha(a0, a1, alphaTable[4 * k + 0]), t0);
+				if (4 * j + 1 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 1] = ddsGetDXTColor(c0, c1, ddsGetDXT5Alpha(a0, a1, alphaTable[4 * k + 1]), t1);
+				if (4 * j + 2 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 2] = ddsGetDXTColor(c0, c1, ddsGetDXT5Alpha(a0, a1, alphaTable[4 * k + 2]), t2);
+				if (4 * j + 3 >= width) continue;
+				pixels[4 * width*i + 4 * j + width*k + 3] = ddsGetDXTColor(c0, c1, ddsGetDXT5Alpha(a0, a1, alphaTable[4 * k + 3]), t3);
+			}
+		}
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsDecodeDXT4(int width, int height, const unsigned char *buffer) {
+	return ddsDecodeDXT5(width, height, buffer);
+}
+
+guchar *ddsReadA1R5G5B5(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4*width*height);
+	for (int i = 0; i<height*width; i++) {
+		int rgba = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+		int r = BIT5[(rgba & A1R5G5B5_MASKS[0]) >> 10];
+		int g = BIT5[(rgba & A1R5G5B5_MASKS[1]) >> 5];
+		int b = BIT5[(rgba & A1R5G5B5_MASKS[2])];
+		int a = 255 * ((rgba & A1R5G5B5_MASKS[3]) >> 15);
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadX1R5G5B5(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int rgba = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+		int r = BIT5[(rgba & X1R5G5B5_MASKS[0]) >> 10];
+		int g = BIT5[(rgba & X1R5G5B5_MASKS[1]) >> 5];
+		int b = BIT5[(rgba & X1R5G5B5_MASKS[2])];
+		int a = 255;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadA4R4G4B4(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int rgba = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+		int r = 17 * ((rgba & A4R4G4B4_MASKS[0]) >> 8);
+		int g = 17 * ((rgba & A4R4G4B4_MASKS[1]) >> 4);
+		int b = 17 * ((rgba & A4R4G4B4_MASKS[2]));
+		int a = 17 * ((rgba & A4R4G4B4_MASKS[3]) >> 12);
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadX4R4G4B4(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int rgba = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+		int r = 17 * ((rgba & A4R4G4B4_MASKS[0]) >> 8);
+		int g = 17 * ((rgba & A4R4G4B4_MASKS[1]) >> 4);
+		int b = 17 * ((rgba & A4R4G4B4_MASKS[2]));
+		int a = 255;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadR5G6B5(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int rgba = (buffer[index] & 0xFF) | (buffer[index + 1] & 0xFF) << 8; index += 2;
+		int r = BIT5[((rgba & R5G6B5_MASKS[0]) >> 11)];
+		int g = BIT6[((rgba & R5G6B5_MASKS[1]) >> 5)];
+		int b = BIT5[((rgba & R5G6B5_MASKS[2]))];
+		int a = 255;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadR8G8B8(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int b = buffer[index++] & 0xFF;
+		int g = buffer[index++] & 0xFF;
+		int r = buffer[index++] & 0xFF;
+		int a = 255;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadA8B8G8R8(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int r = buffer[index++] & 0xFF;
+		int g = buffer[index++] & 0xFF;
+		int b = buffer[index++] & 0xFF;
+		int a = buffer[index++] & 0xFF;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadX8B8G8R8(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int r = buffer[index++] & 0xFF;
+		int g = buffer[index++] & 0xFF;
+		int b = buffer[index++] & 0xFF;
+		int a = 255; index++;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadA8R8G8B8(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int b = buffer[index++] & 0xFF;
+		int g = buffer[index++] & 0xFF;
+		int r = buffer[index++] & 0xFF;
+		int a = buffer[index++] & 0xFF;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+guchar *ddsReadX8R8G8B8(int width, int height, const unsigned char *buffer) {
+	int index = 128;
+	int *pixels = g_try_malloc(4 * width*height);
+	for (int i = 0; i<height*width; i++) {
+		int b = buffer[index++] & 0xFF;
+		int g = buffer[index++] & 0xFF;
+		int r = buffer[index++] & 0xFF;
+		int a = 255; index++;
+		pixels[i] = (a << 24) | (r << 0) | (g << 8) | (b << 16);
+	}
+	return (guchar *) pixels;
+}
+
+static gboolean image_loader_dds_load (gpointer loader, const guchar *buf, gsize count, GError **error)
+{
+	ImageLoaderDDS *ld = (ImageLoaderDDS *) loader;
+	int width = ddsGetWidth(buf);
+	int height = ddsGetHeight(buf);
+	int type = ddsGetType(buf);
+	if (type == 0) return FALSE;
+	{
+		guchar *pixels = NULL;
+		gint rowstride = width * 4;
+		switch (type) {
+		case DXT1: pixels = ddsDecodeDXT1(width, height, buf); break;
+		case DXT2: pixels = ddsDecodeDXT2(width, height, buf); break;
+		case DXT3: pixels = ddsDecodeDXT3(width, height, buf); break;
+		case DXT4: pixels = ddsDecodeDXT4(width, height, buf); break;
+		case DXT5: pixels = ddsDecodeDXT5(width, height, buf); break;
+		case A1R5G5B5: pixels = ddsReadA1R5G5B5(width, height, buf); break;
+		case X1R5G5B5: pixels = ddsReadX1R5G5B5(width, height, buf); break;
+		case A4R4G4B4: pixels = ddsReadA4R4G4B4(width, height, buf); break;
+		case X4R4G4B4: pixels = ddsReadX4R4G4B4(width, height, buf); break;
+		case R5G6B5: pixels = ddsReadR5G6B5(width, height, buf); break;
+		case R8G8B8: pixels = ddsReadR8G8B8(width, height, buf); break;
+		case A8B8G8R8: pixels = ddsReadA8B8G8R8(width, height, buf); break;
+		case X8B8G8R8: pixels = ddsReadX8B8G8R8(width, height, buf); break;
+		case A8R8G8B8: pixels = ddsReadA8R8G8B8(width, height, buf); break;
+		case X8R8G8B8: pixels = ddsReadX8R8G8B8(width, height, buf); break;
+		}
+		ld->pixbuf = gdk_pixbuf_new_from_data (pixels, GDK_COLORSPACE_RGB, TRUE, 8, width, height, rowstride, free_buffer, NULL);
+		ld->area_updated_cb(loader, 0, 0, width, height, ld->data);
+		return TRUE;
+	}
+}
+
+static gpointer image_loader_dds_new(ImageLoaderBackendCbAreaUpdated area_updated_cb, ImageLoaderBackendCbSize size_cb, ImageLoaderBackendCbAreaPrepared area_prepared_cb, gpointer data)
+{
+	ImageLoaderDDS *loader = g_new0(ImageLoaderDDS, 1);
+	loader->area_updated_cb = area_updated_cb;
+	loader->size_cb = size_cb;
+	loader->area_prepared_cb = area_prepared_cb;
+	loader->data = data;
+	return (gpointer) loader;
+}
+
+static void image_loader_dds_set_size(gpointer loader, int width, int height)
+{
+	ImageLoaderDDS *ld = (ImageLoaderDDS *) loader;
+	ld->requested_width = width;
+	ld->requested_height = height;
+}
+
+static GdkPixbuf* image_loader_dds_get_pixbuf(gpointer loader)
+{
+	ImageLoaderDDS *ld = (ImageLoaderDDS *) loader;
+	return ld->pixbuf;
+}
+
+static gchar* image_loader_dds_get_format_name(gpointer loader)
+{
+	return g_strdup("dds");
+}
+static gchar** image_loader_dds_get_format_mime_types(gpointer loader)
+{
+	static gchar *mime[] = {"image/vnd-ms.dds", NULL};
+	return g_strdupv(mime);
+}
+
+static gboolean image_loader_dds_close(gpointer loader, GError **error)
+{
+	return TRUE;
+}
+
+static void image_loader_dds_abort(gpointer loader)
+{
+	ImageLoaderDDS *ld = (ImageLoaderDDS *) loader;
+	ld->abort = TRUE;
+}
+
+static void image_loader_dds_free(gpointer loader)
+{
+	ImageLoaderDDS *ld = (ImageLoaderDDS *) loader;
+	if (ld->pixbuf) g_object_unref(ld->pixbuf);
+	g_free(ld);
+}
+
+void image_loader_backend_set_dds(ImageLoaderBackend *funcs)
+{
+	funcs->loader_new = image_loader_dds_new;
+	funcs->set_size = image_loader_dds_set_size;
+	funcs->load = image_loader_dds_load;
+	funcs->write = NULL;
+	funcs->get_pixbuf = image_loader_dds_get_pixbuf;
+	funcs->close = image_loader_dds_close;
+	funcs->abort = image_loader_dds_abort;
+	funcs->free = image_loader_dds_free;
+	funcs->get_format_name = image_loader_dds_get_format_name;
+	funcs->get_format_mime_types = image_loader_dds_get_format_mime_types;
+}
+
+/* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */
diff -r fa71e9331b53 -r 1618f87e1ae8 src/image_load_dds.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/image_load_dds.h	Fri Apr 06 17:43:03 2018 +0100
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 The Geeqie Team
+ *
+ * Author: Wolfgang Lieff
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef IMAGE_LOAD_DDS_H
+#define IMAGE_LOAD_DDS_H
+
+void image_loader_backend_set_dds(ImageLoaderBackend *funcs);
+
+#endif
+
+/* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */
diff -r fa71e9331b53 -r 1618f87e1ae8 web/help/GuideReferenceSupportedFormats.html
--- a/web/help/GuideReferenceSupportedFormats.html	Tue Apr 03 13:08:34 2018 +0100
+++ b/web/help/GuideReferenceSupportedFormats.html	Fri Apr 06 17:43:03 2018 +0100
@@ -458,7 +458,7 @@
 <li class="linktrail linktrail-first"><a class="linktrail" href="GuideIndex.html" title="The Geeqie User Manual">The Geeqie User Manual</a></li>
 <li class="linktrail linktrail-last"><a class="linktrail" href="GuideReference.html" title="Reference">Reference</a></li>
 </ul>
-<p class="para block block-first">3FR, ANI, APM, ARW, BMP, CR2, CRW, CUR, DNG, ERF, GIF, ICNS, ICO, JPE/JPEG/JPG, JPS, KDC, MEF, MPO, MOS, MRW, NEF, ORF, PEF, PTX, PBM/PGM/PNM/PPM, PNG, QIF/QTIF (QuickTime Image Format), RAF, RAW, RW2, SR2, SRF, SVG/SVGZ, TGA/TARGA, TIF/TIFF, WMF, XBM, XPM. Animated GIFs are supported.</p>
+<p class="para block block-first">3FR, ANI, APM, ARW, BMP, CR2, CRW, CUR, DDS, DNG, ERF, GIF, ICNS, ICO, JPE/JPEG/JPG, JPS, KDC, MEF, MPO, MOS, MRW, NEF, ORF, PEF, PTX, PBM/PGM/PNM/PPM, PNG, QIF/QTIF (QuickTime Image Format), RAF, RAW, RW2, SR2, SRF, SVG/SVGZ, TGA/TARGA, TIF/TIFF, WMF, XBM, XPM. Animated GIFs are supported.</p>
 <p class="para block">
     Refer to
     <a class="link" href="GuideReferencePixbufLoaders.html" title="Additional pixbuf loaders">Additional pixbuf loaders</a>