From d19ef1d0ccee480cd8f56c1f8518f08348098aa4 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@alientrap.org>
Date: Fri, 24 Dec 2010 18:16:33 +0100
Subject: [PATCH] make the texture compression control sensitive towards
 support of the feature

---
 qcsrc/menu/xonotic/slider_picmip.c |  8 +++---
 qcsrc/menu/xonotic/util.qc         | 41 +++++++++++++++++++++++++++---
 qcsrc/menu/xonotic/util.qh         |  3 +++
 3 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/qcsrc/menu/xonotic/slider_picmip.c b/qcsrc/menu/xonotic/slider_picmip.c
index e906242fe4..7ffc626a8b 100644
--- a/qcsrc/menu/xonotic/slider_picmip.c
+++ b/qcsrc/menu/xonotic/slider_picmip.c
@@ -3,6 +3,7 @@ CLASS(XonoticPicmipSlider) EXTENDS(XonoticTextSlider)
 	METHOD(XonoticPicmipSlider, configureXonoticPicmipSlider, void(entity))
 	METHOD(XonoticPicmipSlider, draw, void(entity))
 	METHOD(XonoticPicmipSlider, autofix, void(entity))
+	ATTRIB(XonoticPicmipSlider, have_s3tc, float, 0)
 ENDCLASS(XonoticPicmipSlider)
 entity makeXonoticPicmipSlider(); // note: you still need to call addValue and configureXonoticTextSliderValues!
 #endif
@@ -19,14 +20,15 @@ void XonoticPicmipSlider_configureXonoticPicmipSlider(entity me)
 {
 	me.configureXonoticTextSlider(me, "gl_picmip");
 	me.autofix(me);
+	me.have_s3tc = GL_Have_TextureCompression();
 }
-float texmemsize()
+float texmemsize(float s3tc)
 {
 	return
 	(
 		  2500 * pow(0.5, max(0, cvar("gl_picmip") + cvar("gl_picmip_other")))
 		+ 1500 * pow(0.5, max(0, cvar("gl_picmip") + cvar("gl_picmip_world")))
-	) * ((cvar("r_texture_dds_load") || cvar("gl_texturecompression")) ? 0.4 : 1.0); // TC: normalmaps 50%, other 25%, few incompressible, guessing 40% as conservative average
+	) * (s3tc && ((cvar("r_texture_dds_load") || cvar("gl_texturecompression")) ? 0.4 : 1.0)); // TC: normalmaps 50%, other 25%, few incompressible, guessing 40% as conservative average
 }
 void XonoticPicmipSlider_autofix(entity me)
 {
@@ -35,7 +37,7 @@ void XonoticPicmipSlider_autofix(entity me)
 	max_soft = cvar("sys_memsize_physical");
 	if(max_hard > 0)
 	{
-		while(me.value > 0 && texmemsize() > max_hard)
+		while(me.value > 0 && texmemsize(me.have_s3tc) > max_hard)
 			me.setValue(me, me.value - 1);
 	}
 	// TODO also check the soft limit!
diff --git a/qcsrc/menu/xonotic/util.qc b/qcsrc/menu/xonotic/util.qc
index c968c60acc..f6ffa387c9 100644
--- a/qcsrc/menu/xonotic/util.qc
+++ b/qcsrc/menu/xonotic/util.qc
@@ -1,3 +1,13 @@
+float GL_CheckExtension(string ext)
+{
+	return (strstrofs(strcat(" ", cvar_string("gl_info_extensions"), " "), strcat(" ", ext, " "), 0) >= 0);
+}
+
+float GL_Have_TextureCompression()
+{
+	return (GL_CheckExtension("GL_EXT_texture_compression_s3tc") && GL_CheckExtension("GL_ARB_texture_compression"));
+}
+
 float tooltipdb;
 void loadTooltips()
 {
@@ -459,29 +469,52 @@ float updateCompression()
 {
 	float fh;
 	float have_dds, have_jpg, have_tga;
+	float can_dds;
 	if((have_dds = ((fh = fopen("dds/particles/particlefont.dds", FILE_READ)) >= 0)))
 		fclose(fh);
 	if((have_jpg = ((fh = fopen("particles/particlefont.jpg", FILE_READ)) >= 0)))
 		fclose(fh);
 	if((have_tga = ((fh = fopen("particles/particlefont.tga", FILE_READ)) >= 0)))
 		fclose(fh);
+	can_dds = GL_Have_TextureCompression();
 	if(have_dds && (have_jpg || have_tga))
 	{
 		// both? Let's only use good quality precompressed files
-		cvar_set("gl_texturecompression", "0");
-		return 1;
+		// but ONLY if we actually support it!
+		if(can_dds)
+		{
+			cvar_set("gl_texturecompression", "0");
+			return 1;
+		}
+		else
+		{
+			cvar_set("gl_texturecompression", "0");
+			cvar_set("r_texture_dds_load", "0");
+			return 0;
+		}
 	}
 	else if(have_dds)
 	{
 		// DDS only? We probably always want texture compression
 		cvar_set("gl_texturecompression", "1");
 		cvar_set("r_texture_dds_load", "1");
+		if(!can_dds)
+			print("^1ERROR: Texture compression is required but not supported.\n^1Expect visual problems.\n");
 		return 0;
 	}
 	else
 	{
 		// TGA only? Allow runtime compression
-		cvar_set("gl_texturecompression", cvar_string("r_texture_dds_load"));
-		return 2;
+		if(can_dds)
+		{
+			cvar_set("gl_texturecompression", cvar_string("r_texture_dds_load"));
+			return 2;
+		}
+		else
+		{
+			cvar_set("gl_texturecompression", "0");
+			cvar_set("r_texture_dds_load", "0");
+			return 0;
+		}
 	}
 }
diff --git a/qcsrc/menu/xonotic/util.qh b/qcsrc/menu/xonotic/util.qh
index ace912dc21..053c507309 100644
--- a/qcsrc/menu/xonotic/util.qh
+++ b/qcsrc/menu/xonotic/util.qh
@@ -1,3 +1,6 @@
+float GL_CheckExtension(string ext);
+float GL_Have_TextureCompression();
+
 void forAllDescendants(entity root, void(entity, entity) funcPre, void(entity, entity) funcPost, entity pass);
 void saveAllCvars(entity root);
 void loadAllCvars(entity root);
-- 
2.39.2