TA: ISP_BACKGND_D has only 28 bits of precision

Calculate background depth accordingly
add extradepthscaling of 0.1 to wince games so the last four bits of
depth are significant

core/hw/pvr/ta_vtx.cpp

@@ -1726,18 +1726,20 @@ void FillBGP(TA_context* ctx)
 	}
 
 	float ZV=0;
+	f32 bg_depth = ISP_BACKGND_D.f;
+	reinterpret_cast<u32&>(bg_depth) &= 0xFFFFFFF0;	// ISP_BACKGND_D has only 28 bits
 
 	cv[0].x=-2000;
 	cv[0].y=-2000;
-	cv[0].z=ISP_BACKGND_D.f;
+	cv[0].z=bg_depth;
 
 	cv[1].x=640*scale_x + 2000;
 	cv[1].y=0;
-	cv[1].z=ISP_BACKGND_D.f;
+	cv[1].z=bg_depth;
 
 	cv[2].x=-2000;
 	cv[2].y=480+2000;
-	cv[2].z=ISP_BACKGND_D.f;
+	cv[2].z=bg_depth;
 
 	cv[3]=cv[2];
 	cv[3].x=640*scale_x+2000;

core/nullDC.cpp

@@ -138,6 +138,13 @@ void LoadSpecialSettings()
 	tr_poly_depth_mask_game = false;
 	extra_depth_game = false;
 	
+	if (reios_windows_ce)
+	{
+		printf("Enabling Extra depth scaling for Windows CE games\n");
+		settings.rend.ExtraDepthScale = 0.1;
+		extra_depth_game = true;
+	}
+
 	// Tony Hawk's Pro Skater 2
 	if (!strncmp("T13008D", reios_product_number, 7) || !strncmp("T13006N", reios_product_number, 7)
 			// Tony Hawk's Pro Skater 1

core/reios/reios.cpp

@@ -114,6 +114,7 @@ char reios_boot_filename[17];
 char reios_software_company[17];
 char reios_software_name[129];
 char reios_bootfile[32];
+bool reios_windows_ce = false;
 
 bool pre_init = false;
 
@@ -150,6 +151,7 @@ char* reios_disk_id() {
 	memcpy(&reios_boot_filename[0], &ip_bin[96],   16 * sizeof(char));
 	memcpy(&reios_software_company[0], &ip_bin[112],   16 * sizeof(char));
 	memcpy(&reios_software_name[0], &ip_bin[128],   128 * sizeof(char));
+	reios_windows_ce = memcmp("0WINCEOS.BIN", &reios_boot_filename[0], 12) == 0;
 
 	return reios_product_number;
 }

core/reios/reios.h

@@ -14,6 +14,7 @@ void DYNACALL reios_trap(u32 op);
 char* reios_disk_id();
 extern char reios_software_name[129];
 extern char reios_product_number[11];
+extern bool reios_windows_ce;
 
 #define REIOS_OPCODE 0x085B