Use stb_image for retexturing support, also support png, no more libjpeg

Retexturing support is now always on (you can still switch it off with
the gl_retexturing  CVAR), as we don't have the additional libjpeg
dependency anymore.

stb_image is used for tga, jpg and the newly supported png, so the
old tga and jpeg loading code has been removed.

I furthermore cleaned up the somehow messy and possibly slightly broken
retexturing selection code in R_FindImage()

Author: DanielGibson

Makefile

@@ -11,7 +11,6 @@
 #  - libGL                                               #
 #                                                        #
 # Further dependencies:                                  #
-#  - libjpeg                                             #
 #  - libogg                                              #
 #  - libvorbis                                           #
 #  - OpenAL                                              #
@@ -45,10 +44,6 @@ WITH_OGG:=yes
 # installed
 WITH_OPENAL:=yes
 
-# Enables retexturing support. Adds
-# a dependency to libjpeg
-WITH_RETEXTURING:=yes
-
 # Use SDL2 instead of SDL1.2. Disables CD audio support,
 # because SDL2 has none. Use OGG/Vorbis music instead :-)
 # On Windows sdl-config isn't used, so make sure that
@@ -165,7 +160,7 @@ CFLAGS := -O2 -fno-strict-aliasing -fomit-frame-pointer \
 CFLAGS += $(OSX_ARCH)
 else
 CFLAGS := -O2 -fno-strict-aliasing -fomit-frame-pointer \
-		  -Wall -pipe -g -MMD
+		  -Wall -pipe -g -ggdb -MMD
 endif
 
 # ----------
@@ -312,7 +307,6 @@ config:
 	@echo "============================"
 	@echo "WITH_CDA = $(WITH_CDA)"
 	@echo "WITH_OPENAL = $(WITH_OPENAL)"
-	@echo "WITH_RETEXTURING = $(WITH_RETEXTURING)"
 	@echo "WITH_SDL2 = $(WITH_SDL2)"
 	@echo "WITH_X11GAMMA = $(WITH_X11GAMMA)"
 	@echo "WITH_ZIP = $(WITH_ZIP)"
@@ -376,11 +370,6 @@ ifeq ($(WITH_ZIP),yes)
 release/quake2.exe : CFLAGS += -DZIP -DNOUNCRYPT
 release/quake2.exe : LDFLAGS += -lz
 endif
- 
-ifeq ($(WITH_RETEXTURING),yes)
-release/quake2.exe : CFLAGS += -DRETEXTURE
-release/quake2.exe : LDFLAGS += -ljpeg
-endif 
 
 ifeq ($(WITH_SDL2),yes)
 release/quake2.exe : CFLAGS += -DSDL2
@@ -438,15 +427,6 @@ ifeq ($(WITH_X11GAMMA),yes)
 release/quake2 : CFLAGS += -DX11GAMMA
 endif
 
-ifeq ($(WITH_RETEXTURING),yes)
-release/quake2 : CFLAGS += -DRETEXTURE
-ifeq ($(OSTYPE), Darwin)
-release/quake2 : LDFLAGS += -framework libjpeg
-else
-release/quake2 : LDFLAGS += -ljpeg
-endif
-endif
-
 ifeq ($(WITH_SDL2),yes)
 release/quake2 : CFLAGS += -DSDL2
 endif
@@ -649,8 +629,7 @@ CLIENT_OBJS_ := \
 	src/client/refresh/files/md2.o \
 	src/client/refresh/files/pcx.o \
 	src/client/refresh/files/sp2.o \
-	src/client/refresh/files/tga.o \
-	src/client/refresh/files/jpeg.o \
+	src/client/refresh/files/stb.o \
 	src/client/refresh/files/wal.o \
 	src/client/menu/menu.o \
 	src/client/menu/qmenu.o \

src/client/refresh/files/jpeg.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 1997-2001 Id Software, Inc.
+ * Copyright (C) 2015 Daniel Gibson
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * =======================================================================
+ *
+ * File formats supported by stb_image, for now only tga, png, jpg
+ * See also https://github.com/nothings/stb
+ *
+ * =======================================================================
+ */
+
+#include <stdlib.h>
+
+#include "../header/local.h"
+
+// don't need HDR stuff
+#define STBI_NO_LINEAR
+#define STBI_NO_HDR
+// make sure STB_image uses standard malloc(), as we'll use standard free() to deallocate
+#define STBI_MALLOC(sz)    malloc(sz)
+#define STBI_REALLOC(p,sz) realloc(p,sz)
+#define STBI_FREE(p)       free(p)
+// include implementation part of stb_image into this file
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+
+/*
+ * origname: the filename to be opened, might be without extension
+ * type: extension of the type we wanna open ("jpg", "png" or "tga")
+ * pic: pointer RGBA pixel data will be assigned to
+ */
+qboolean
+LoadSTB(const char *origname, const char* type, byte **pic, int *width, int *height)
+{
+	char filename[256];
+
+	Q_strlcpy(filename, origname, sizeof(filename));
+
+	/* Add the extension */
+	if (strcmp(COM_FileExtension(filename), type) != 0)
+	{
+		Q_strlcat(filename, ".", sizeof(filename));
+		Q_strlcat(filename, type, sizeof(filename));
+	}
+
+	*pic = NULL;
+
+	byte* rawdata = NULL;
+	int rawsize = FS_LoadFile(filename, (void **)&rawdata);
+	if (rawdata == NULL)
+	{
+		return false;
+	}
+
+	int w, h, bytesPerPixel;
+	byte* data = NULL;
+	data = stbi_load_from_memory(rawdata, rawsize, &w, &h, &bytesPerPixel, STBI_rgb_alpha);
+	if (data == NULL)
+	{
+		VID_Printf(PRINT_ALL, "stb_image couldn't load data from %s: %s!\n", filename, stbi_failure_reason());
+		FS_FreeFile(rawdata);
+		return false;
+	}
+
+	FS_FreeFile(rawdata);
+
+	VID_Printf(PRINT_DEVELOPER, "LoadSTB() loaded: %s\n", filename);
+
+	*pic = data;
+	*width = w;
+	*height = h;
+	return true;
+}
+
+
+