Add an option to color crosshair according to player health + shield

Shield is taken into account and is added to health for the calculation,
as the vast majority of damage types are fully blocked by a shield.

3 modes are available:

- Off (default)
- On (Green): Goes through a red-yellow-green-cyan gradient,
  closer to vanilla.
- On (White): Goes through a red-yellow-white-green gradient,
  closer to games like Xonotic.

When set to either of the On modes, the crosshair color setting
is ignored but the crosshair alpha setting is still used.

port/src/main.c

@@ -176,5 +176,6 @@ PD_CONSTRUCTOR static void gameConfigInit(void)
 		configRegisterInt(strFmt("Game.Player%d.ExtendedControls", i), &g_PlayerExtCfg[j].extcontrols, 0, 1);
 		configRegisterUInt(strFmt("Game.Player%d.CrosshairColour", i), &g_PlayerExtCfg[j].crosshaircolour, 0, 0xFFFFFFFF);
 		configRegisterUInt(strFmt("Game.Player%d.CrosshairSize", i), &g_PlayerExtCfg[j].crosshairsize, 0, 4);
+		configRegisterInt(strFmt("Game.Player%d.CrosshairHealth", i), &g_PlayerExtCfg[j].crosshairhealth, 0, CROSSHAIR_HEALTH_ON_WHITE);
 	}
 }

port/src/optionsmenu.c

@@ -1040,6 +1040,30 @@ static MenuItemHandlerResult menuhandlerCrosshairSize(s32 operation, struct menu
 	return 0;
 }
 
+static MenuItemHandlerResult menuhandlerCrosshairHealth(s32 operation, struct menuitem *item, union handlerdata *data)
+{
+	static const char *opts[] = {
+		"Off",
+		"On (Green)",
+		"On (White)"
+	};
+
+	switch (operation) {
+	case MENUOP_GETOPTIONCOUNT:
+		data->dropdown.value = ARRAYCOUNT(opts);
+		break;
+	case MENUOP_GETOPTIONTEXT:
+		return (intptr_t)opts[data->dropdown.value];
+	case MENUOP_SET:
+		g_PlayerExtCfg[g_ExtMenuPlayer].crosshairhealth = data->dropdown.value;
+		break;
+	case MENUOP_GETSELECTEDINDEX:
+		data->dropdown.value = g_PlayerExtCfg[g_ExtMenuPlayer].crosshairhealth;
+	}
+
+	return 0;
+}
+
 struct menuitem g_ExtendedGameCrosshairColourMenuItems[] = {
 	{
 		MENUITEMTYPE_SLIDER,
@@ -1158,6 +1182,14 @@ struct menuitem g_ExtendedGameMenuItems[] = {
 		0,
 		(void*)&g_ExtendedGameCrosshairColourMenuDialog,
 	},
+	{
+		MENUITEMTYPE_DROPDOWN,
+		0,
+		MENUITEMFLAG_LITERAL_TEXT,
+		(uintptr_t)"Crosshair Colour by Health",
+		0,
+		menuhandlerCrosshairHealth,
+	},
 	{
 		MENUITEMTYPE_SEPARATOR,
 		0,

src/game/mplayer/mplayer.c

@@ -124,6 +124,7 @@ struct mpweapon g_MpWeapons[NUM_MPWEAPONS] = {
 	.extcontrols = true, \
 	.crosshaircolour = 0x00ff0028, \
 	.crosshairsize = 2, \
+	.crosshairhealth = CROSSHAIR_HEALTH_OFF, \
 }
 
 struct extplayerconfig g_PlayerExtCfg[MAX_PLAYERS] = { 

src/game/sight.c

@@ -23,9 +23,55 @@
 #include <math.h>
 #include "video.h"
 
-#define SIGHT_COLOUR PLAYER_EXTCFG().crosshaircolour
+#define SIGHT_COLOUR ((PLAYER_EXTCFG().crosshairhealth >= CROSSHAIR_HEALTH_ON_GREEN) ? sightGetCrosshairHealthColor(g_Vars.currentplayer->bondhealth, g_Vars.currentplayer->prop->chr->cshield * 0.125f) : PLAYER_EXTCFG().crosshaircolour)
 #define SIGHT_SCALE PLAYER_EXTCFG().crosshairsize
 
+static u32 sightGetCrosshairHealthColor(float health, float shield)
+{
+	const float ratio = MAX(0.0f, MIN(health + shield, 2.0f));
+
+	int red = 0;
+	int green = 0;
+	int blue = 0;
+	if (ratio < 0.2f) {
+		// Red (critical health level)
+		red = 255;
+		green = 0;
+		blue = 0;
+	} else if (ratio < 0.6f) {
+		// Red-yellow
+		red = 255;
+		green = 255 * ((ratio - 0.2f) / 0.4f);
+		blue = 0;
+	} else if (ratio < 1.0f) {
+		if (PLAYER_EXTCFG().crosshairhealth == CROSSHAIR_HEALTH_ON_GREEN) {
+			// Yellow-green
+			red = 255 * ((ratio - 0.6f) / 0.4f);
+			green = 255;
+			blue = 0;
+		} else {
+			// Yellow-white
+			red = 255;
+			green = 255;
+			blue = 255 * ((ratio - 0.6f) / 0.4f);
+		}
+	} else {
+		if (PLAYER_EXTCFG().crosshairhealth == CROSSHAIR_HEALTH_ON_GREEN) {
+			// Green-cyan (overheal via shield)
+			red = 0;
+			green = 255;
+			blue = 255 * (ratio - 1.0f);
+		} else {
+			// White-green (overheal via shield)
+			red = 255 * (2.0f - ratio);
+			green = 255;
+			blue = 255 * (2.0f - ratio);
+		}
+	}
+
+	return (red << 24) + (green << 16) + (blue << 8) + (PLAYER_EXTCFG().crosshaircolour & 0xff);
+}
+
 static inline f32 sightGetScaleX(void)
 {
 	return (videoGetAspect() / SCREEN_ASPECT);

src/include/constants.h

@@ -4718,6 +4718,10 @@ enum weaponnum {
 #define CROUCHMODE_TOGGLE 2 // press the crouch buttons to toggle stance
 #define CROUCHMODE_TOGGLE_ANALOG (CROUCHMODE_ANALOG | CROUCHMODE_TOGGLE)
 
+#define CROSSHAIR_HEALTH_OFF 0
+#define CROSSHAIR_HEALTH_ON_GREEN 1
+#define CROSSHAIR_HEALTH_ON_WHITE 2
+
 #endif
 
 #endif

src/include/types.h

@@ -6141,6 +6141,7 @@ struct extplayerconfig {
 	s32 extcontrols;
 	u32 crosshaircolour;
 	u32 crosshairsize;
+	s32 crosshairhealth;
 };
 
 #endif