Add support for .relative & .centered

When using .relative & .centered tags for PixelScrolling, do the following:
- Get half the width/height of the screen
- Move screen by ( h/v - screen_width/height ) divided by two.

When compared to Maniacs Patch 240822, it works as expected.
Tested using different resolutions, works like it should.

Revert "Add support for .relative & .centered"

This reverts commit 7525e75.

Add support for .relative & .centered

When using .relative & .centered tags for PixelScrolling, do the following:
- Get half the width/height of the screen
- Move screen by ( h/v - screen_width/height ) divided by two.

When compared to Maniacs Patch 240822, it works as expected.
Tested using different resolutions, works like it should.

src/game_interpreter_map.cpp

@@ -608,15 +608,6 @@ bool Game_Interpreter_Map::CommandPanScreen(lcf::rpg::EventCommand const& com) {
 	int speed;
 	bool waiting_pan_screen = false;
 
-	// Maniac has new functions for pixel scrolling, which also have X and Y offsets
-	bool is_maniac = Player::IsPatchManiac();
-	int h;
-	int v;
-	double h_speed;
-	double v_speed;
-	bool centered = false;
-	bool relative = false;
-
 	auto& player = *Main_Data::game_player;
 
 	switch (com.parameters[0]) {
@@ -645,34 +636,6 @@ bool Game_Interpreter_Map::CommandPanScreen(lcf::rpg::EventCommand const& com) {
 		distance /= SCREEN_TILE_SIZE;
 		break;
 	}
-	if (is_maniac && com.parameters.size() > 5) {
-		h = ValueOrVariableBitfield(com, 1, 0, 2);
-		v = ValueOrVariableBitfield(com, 1, 1, 3);
-		waiting_pan_screen = (com.parameters[4] & 0x01) != 0;
-		speed = ValueOrVariableBitfield(com, 1, 2, 5);
-		switch (com.parameters[0]) {
-		case 4: // Relative Pixel Pan (speed)
-			centered = false;
-			relative = true;
-			player.StartPixelPan(h, v, speed, false, centered, relative);
-			break;
-		case 5: // Relative Pixel Pan (interpolated)
-			centered = false;
-			relative = true;
-			player.StartPixelPan(h, v, speed, true, centered, relative);
-			break;
-		case 6: // Absolute Pixel Pan (speed)
-			centered = (com.parameters[4] & 0x02) != 0;
-			relative = (com.parameters[4] & 0x04) != 0;
-			player.StartPixelPan(h, v, speed, false, centered, relative);
-			break;
-		case 7: // Absolute Pixel Pan (interpolated)
-			centered = (com.parameters[4] & 0x02) != 0;
-			relative = (com.parameters[4] & 0x04) != 0;
-			player.StartPixelPan(h, v, speed, true, centered, relative);
-			break;
-		}
-	}
 
 	if (Player::IsPatchManiac() && com.parameters.size() > 5) {
 		// Pixel scrolling with h/v offsets

src/game_player.cpp

@@ -811,8 +811,12 @@ void Game_Player::StartPixelPan(int h, int v, int speed, bool interpolated, bool
 	int new_pan_x;
 	int new_pan_y;
 
-	// FIXME: Fails when relative and centered are used in combination
-	if (relative) {
+	if (relative && centered) {
+		int screen_width = static_cast<int>(std::ceil(static_cast<float>(Player::screen_width) / 2)) * TILE_SIZE;
+		int screen_height = static_cast<int>(std::ceil(static_cast<float>(Player::screen_height) / 2)) * TILE_SIZE;
+		new_pan_x = data()->pan_finish_x - (h - screen_width) * 0.5;
+		new_pan_y = data()->pan_finish_y - (v - screen_height) * 0.5;
+	} else if (relative) {
 		new_pan_x = data()->pan_finish_x - h;
 		new_pan_y = data()->pan_finish_y - v;
 	} else if (centered) {