Make texture compression optional.

Two variants:

1. Use the --notexturecompression command line option.

2. Put "notexturecompression=1" into the config file. Can be overridden
with the --texturecompression command line option.

Closes #2864.

doc/warzone2100.6.asciidoc

@@ -71,6 +71,11 @@ work anymore.
 *--(no)sound*::
       Toggle the sound.
 
+*--(no)texturecompression*::
+      Toggle texture compression (default on). At least on systems where Mesa's
+      libtxc-dxtn handles texture compression, loading is slower with it enabled.
+      In-game FPS are also higher though.
+
 The fullscreen/window, resolution,  sound,  and  shadows  settings  are
 stored,  so  they  only  need to be specified once, or when you want to
 change them.

lib/ivis_opengl/piemode.cpp

@@ -53,7 +53,7 @@ bool pie_Initialise(void)
 	pie_TexInit();
 
 	/* Find texture compression extension */
-	if (GLEW_ARB_texture_compression)
+	if (GLEW_ARB_texture_compression && wz_texture_compression != GL_RGBA)
 	{
 		debug(LOG_TEXTURE, "Texture compression: Yes");
 		wz_texture_compression = GL_COMPRESSED_RGBA_ARB;

lib/ivis_opengl/screen.cpp

@@ -43,7 +43,7 @@
 #include "src/levels.h"
 
 /* global used to indicate preferred internal OpenGL format */
-int wz_texture_compression;
+int wz_texture_compression = 0;
 
 static bool		bBackDrop = false;
 static char		screendump_filename[PATH_MAX];

lib/ivis_opengl/screen.h

@@ -34,6 +34,7 @@
 #endif
 
 #include "lib/framework/types.h"
+#include "lib/framework/vector.h"
 
 /* ------------------------------------------------------------------------------------------- */
 

src/clparse.cpp

@@ -25,6 +25,8 @@
  */
 
 #include "lib/framework/frame.h"
+#include "lib/framework/opengl.h"
+#include "lib/ivis_opengl/screen.h"
 #include "lib/netplay/netplay.h"
 
 #include "clparse.h"
@@ -229,6 +231,8 @@ typedef enum
 	CLI_HOSTLAUNCH,
 	CLI_NOASSERT,
 	CLI_CRASH,
+	CLI_TEXTURECOMPRESSION,
+	CLI_NOTEXTURECOMPRESSION,
 } CLI_OPTIONS;
 
 static const struct poptOption* getOptionsTable(void)
@@ -259,6 +263,8 @@ static const struct poptOption* getOptionsTable(void)
 		{ "selftest",   '\0', POPT_ARG_NONE,   NULL, CLI_SELFTEST,   N_("Activate self-test"),                NULL },
 		{ "join",       '\0', POPT_ARG_STRING, NULL, CLI_CONNECTTOIP,N_("connect directly to IP/hostname"),   N_("host") },
 		{ "host",       '\0', POPT_ARG_NONE,   NULL, CLI_HOSTLAUNCH, N_("go directly to host screen"),        NULL },
+		{ "texturecompression", '\0', POPT_ARG_NONE, NULL, CLI_TEXTURECOMPRESSION, N_("Enable texture compression"), NULL },
+		{ "notexturecompression", '\0', POPT_ARG_NONE, NULL, CLI_NOTEXTURECOMPRESSION, N_("Disable texture compression"), NULL },
 		// Terminating entry
 		{ NULL,         '\0', 0,               NULL, 0,              NULL,                                    NULL },
 	};
@@ -587,6 +593,14 @@ bool ParseCommandLine(int argc, const char** argv)
 			case CLI_SELFTEST:
 				selfTest = true;
 				break;
+
+			case CLI_TEXTURECOMPRESSION:
+				wz_texture_compression = GL_COMPRESSED_RGBA_ARB;
+				break;
+
+			case CLI_NOTEXTURECOMPRESSION:
+				wz_texture_compression = GL_RGBA;
+				break;
 		};
 	}
 

src/configuration.cpp

@@ -66,6 +66,7 @@ bool loadConfig()
 	if (ini.contains("music_enabled")) war_SetMusicEnabled(ini.value("music_enabled").toBool());
 	if (ini.contains("language")) setLanguage(ini.value("language").toString().toUtf8().constData());
 	if (ini.contains("nomousewarp")) setMouseWarp(ini.value("nomousewarp").toBool());
+	if (ini.contains("notexturecompression")) wz_texture_compression = GL_RGBA;
 	showFPS = ini.value("showFPS", false).toBool();
 	scroll_speed_accel = ini.value("scroll", DEFAULTSCROLL).toInt();
 	setShakeStatus(ini.value("shake", false).toBool());