Get rid of one abuse of the vga palette index of a COLOR to store state.

git-svn-id: svn://svn.code.sf.net/p/sc2/code/trunk@3358 8092fc87-c524-0410-9efc-e669fe64eaf9

sc2/src/uqm/element.h

@@ -123,7 +123,10 @@ struct element
 		COUNT crew_level;
 		COUNT hit_points;
 		COUNT facing; /* Planetside: lava-spot direction of travel */
-		COUNT cycle;  /* Planetside: lightning cycle length */
+		COUNT cycle;
+				/* Planetside: lightning cycle length
+				 * Melee: color cycle index of ion trails and warp shadows
+				 */
 	};
 	union
 	{

sc2/src/uqm/tactrans.c

@@ -578,14 +578,51 @@ ship_death (ELEMENT *ShipPtr)
 
 #define START_ION_COLOR BUILD_COLOR (MAKE_RGB15 (0x1F, 0x15, 0x00), 0x7A)
 
+// Called from the death_func of an element for an ion trail pixel, or a
+// ship shadow (when warping in/out).
+void
+cycle_ion_trail (ELEMENT *ElementPtr)
+{
+	static const COLOR color_tab[] =
+	{
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x15, 0x00), 0x7a),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x11, 0x00), 0x7b),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x0E, 0x00), 0x7c),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x0A, 0x00), 0x7d),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x07, 0x00), 0x7e),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x03, 0x00), 0x7f),
+		BUILD_COLOR (MAKE_RGB15 (0x1F, 0x00, 0x00), 0x2a),
+		BUILD_COLOR (MAKE_RGB15 (0x1B, 0x00, 0x00), 0x2b),
+		BUILD_COLOR (MAKE_RGB15 (0x17, 0x00, 0x00), 0x2c),
+		BUILD_COLOR (MAKE_RGB15 (0x13, 0x00, 0x00), 0x2d),
+		BUILD_COLOR (MAKE_RGB15 (0x0F, 0x00, 0x00), 0x2e),
+		BUILD_COLOR (MAKE_RGB15 (0x0B, 0x00, 0x00), 0x2f),
+	};
+#define NUM_TAB_COLORS (sizeof color_tab / sizeof color_tab[0])
+			
+	assert (!(ElementPtr->state_flags & PLAYER_SHIP));
+
+	ElementPtr->cycle++;
+	if (ElementPtr->cycle != NUM_TAB_COLORS)
+	{
+		ElementPtr->life_span = ElementPtr->thrust_wait;
+				// Reset the life span.
+		
+		SetPrimColor (&DisplayArray[ElementPtr->PrimIndex],
+				color_tab[ElementPtr->cycle]);
+
+		ElementPtr->state_flags &= ~DISAPPEARING;
+		ElementPtr->state_flags |= CHANGING;
+	} // else, the element disappears.
+}
+
 void
 spawn_ion_trail (ELEMENT *ElementPtr)
-{
-		  
-	if (ElementPtr->state_flags & PLAYER_SHIP)
 {
 	HELEMENT hIonElement;
 
+	assert (ElementPtr->state_flags & PLAYER_SHIP);
+
 	hIonElement = AllocElement ();
 	if (hIonElement)
 	{
@@ -604,10 +641,15 @@ spawn_ion_trail (ELEMENT *ElementPtr)
 		LockElement (hIonElement, &IonElementPtr);
 		IonElementPtr->playerNr = NEUTRAL_PLAYER_NUM;
 		IonElementPtr->state_flags = APPEARING | FINITE_LIFE | NONSOLID;
-			IonElementPtr->life_span = IonElementPtr->thrust_wait = ION_LIFE;
+		IonElementPtr->thrust_wait = ION_LIFE;
+		IonElementPtr->life_span = IonElementPtr->thrust_wait;
+				// When the element "dies", in the death_func
+				// 'cycle_ion_trail', it is given new life a number of
+				// times, by setting life_span to thrust_wait.
 		SetPrimType (&DisplayArray[IonElementPtr->PrimIndex], POINT_PRIM);
 		SetPrimColor (&DisplayArray[IonElementPtr->PrimIndex],
 				START_ION_COLOR);
+		IonElementPtr->cycle = 0;
 		IonElementPtr->current.image.frame =
 				DecFrameIndex (stars_in_space);
 		IonElementPtr->current.image.farray = &stars_in_space;
@@ -616,7 +658,7 @@ spawn_ion_trail (ELEMENT *ElementPtr)
 				(COORD)COSINE (angle, r.extent.height);
 		IonElementPtr->current.location.y +=
 				(COORD)SINE (angle, r.extent.height);
-			IonElementPtr->death_func = spawn_ion_trail;
+		IonElementPtr->death_func = cycle_ion_trail;
 
 		SetElementStarShip (IonElementPtr, StarShipPtr);
 
@@ -633,48 +675,6 @@ spawn_ion_trail (ELEMENT *ElementPtr)
 		UnlockElement (hIonElement);
 	}
 }
-	else
-	{
-		static const COLOR color_tab[] =
-		{
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x00, 0x00), 0x2a),
-			BUILD_COLOR (MAKE_RGB15 (0x1B, 0x00, 0x00), 0x2b),
-			BUILD_COLOR (MAKE_RGB15 (0x17, 0x00, 0x00), 0x2c),
-			BUILD_COLOR (MAKE_RGB15 (0x13, 0x00, 0x00), 0x2d),
-			BUILD_COLOR (MAKE_RGB15 (0x0F, 0x00, 0x00), 0x2e),
-			BUILD_COLOR (MAKE_RGB15 (0x0B, 0x00, 0x00), 0x2f),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x15, 0x00), 0x7a),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x11, 0x00), 0x7b),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x0E, 0x00), 0x7c),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x0A, 0x00), 0x7d),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x07, 0x00), 0x7e),
-			BUILD_COLOR (MAKE_RGB15 (0x1F, 0x03, 0x00), 0x7f),
-		};
-#define NUM_TAB_COLORS (sizeof (color_tab) / sizeof (color_tab[0]))
-				
-		COUNT color_index = 0;
-		COLOR Color;
-
-		Color = COLOR_256 (GetPrimColor (&DisplayArray[ElementPtr->PrimIndex]));
-		if (Color != 0x2F)
-		{
-			ElementPtr->life_span = ElementPtr->thrust_wait;
-			
-			++Color;
-			if (Color > 0x7F)
-				Color = 0x2A;
-			if (Color <= 0x2f && Color >= 0x2a)
-				color_index = (COUNT)Color - 0x2a;
-			else /* color is between 0x7a and 0x7f */
-				color_index = (COUNT)(Color - 0x7a) + (NUM_TAB_COLORS >> 1);
-			SetPrimColor (&DisplayArray[ElementPtr->PrimIndex],
-					color_tab[color_index]);
-
-			ElementPtr->state_flags &= ~DISAPPEARING;
-			ElementPtr->state_flags |= CHANGING;
-		}
-	}
-}
 
 // Preprocess function for spawning a ship into or out of battle.
 // Used when a new ship warps in, or a ship escapes by warping out, but not
@@ -743,12 +743,16 @@ ship_transition (ELEMENT *ElementPtr)
 			LockElement (hShipImage, &ShipImagePtr);
 			ShipImagePtr->playerNr = NEUTRAL_PLAYER_NUM;
 			ShipImagePtr->state_flags = APPEARING | FINITE_LIFE | NONSOLID;
-			ShipImagePtr->life_span = ShipImagePtr->thrust_wait =
+			ShipImagePtr->thrust_wait = TRANSITION_LIFE;
-					TRANSITION_LIFE;
+			ShipImagePtr->life_span = ShipImagePtr->thrust_wait;
+					// When the element "dies", in the death_func
+					// 'cycle_ion_trail', it is given new life a number of
+					// times, by setting life_span to thrust_wait.
 			SetPrimType (&DisplayArray[ShipImagePtr->PrimIndex],
 					STAMPFILL_PRIM);
 			SetPrimColor (&DisplayArray[ShipImagePtr->PrimIndex],
 					START_ION_COLOR);
+			ShipImagePtr->cycle = 0;
 			ShipImagePtr->current.image = ElementPtr->current.image;
 			ShipImagePtr->current.location = ElementPtr->current.location;
 			if (!(ElementPtr->state_flags & PLAYER_SHIP))
@@ -774,7 +778,7 @@ ship_transition (ELEMENT *ElementPtr)
 						WRAP_Y (ShipImagePtr->current.location.y);
 			}
 			ShipImagePtr->preprocess_func = ship_transition;
-			ShipImagePtr->death_func = spawn_ion_trail;
+			ShipImagePtr->death_func = cycle_ion_trail;
 			SetElementStarShip (ShipImagePtr, StarShipPtr);
 
 			UnlockElement (hShipImage);