Implement simple train car

For now, the car just exists at a certain tile and has a 'progress'
timer until it moves to the next track tile.

4 files changed, 90 insertions, 0 deletions

diff --git a/car.png b/car.png
new file mode 100644
index 0000000..ae7c6ff
--- /dev/null
+++ b/car.png
diff --git a/main.cpp b/main.cpp
index 9e3b621..610dbb1 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,6 +4,7 @@
 #include "window.h"
 #include "bitmap.h"
 #include "level.h"
+#include "train.h"
 
 struct Point2D {
 	float x, y;
@@ -89,6 +90,8 @@ int main(int argc, char **argv)
 	int xDrag, yDrag;
 	bool isDragging = false;
 
+	TrainCar car(0, 0);
+
 	window.onMouseDown([&](int button, int x, int y) {
 		if (button == 1) {
 			static const auto update_direction = [&](int xt, int yt) {
@@ -117,6 +120,12 @@ int main(int argc, char **argv)
 			xDrag = x;
 			yDrag = y;
 			isDragging = true;
+		} else {
+			float mx = x / Scale + xOffs;
+			float my = y / Scale + yOffs;
+			auto pos = screenToTile({ mx, my });
+			car.x = pos.x;
+			car.y = pos.y;
 		}
 	});
 
@@ -137,6 +146,8 @@ int main(int argc, char **argv)
 	while (!window.shouldClose()) {
 		window.update();
 		DrawLevel(bitmap, tiles, level, xOffs, yOffs);
+		car.update(level);
+		car.draw(bitmap, xOffs, yOffs);
 		window.draw(bitmap);
 	}
 
diff --git a/train.cpp b/train.cpp
new file mode 100644
index 0000000..e369887
--- /dev/null
+++ b/train.cpp
@@ -0,0 +1,52 @@
+#include "train.h"
+
+#include "level.h"
+#include "bitmap.h"
+
+void TrainCar::update(Level& level)
+{
+	auto tile = level.get(x, y);
+	if (tile == 0)
+		return;
+
+	if (m_progress < 12) {
+		m_progress++;
+		return;
+	}
+	else {
+		m_progress = 0;
+	}
+
+	auto n = level.get(x, y - 1);
+	auto e = level.get(x + 1, y);
+	auto s = level.get(x, y + 1);
+	auto w = level.get(x - 1, y);
+
+	if (m_dir == North) {
+		if (n == SouthEast) m_dir = East;
+		if (n == SouthWest) m_dir = West;
+		y--;
+	}
+	else if (m_dir == East) {
+		if (e == NorthWest) m_dir = North;
+		if (e == SouthWest) m_dir = South;
+		x++;
+	}
+	else if (m_dir == South) {
+		if (s == NorthEast) m_dir = East;
+		if (s == NorthWest) m_dir = West;
+		y++;
+	}
+	else if (m_dir == West) {
+		if (w == NorthEast) m_dir = North;
+		if (w == SouthEast) m_dir = South;
+		x--;
+	}
+}
+
+void TrainCar::draw(Bitmap& bitmap, int xo, int yo)
+{
+	int xx = (x - y) * (24 / 2) - xo;
+	int yy = (x + y) * (24 / 4) - yo;
+	bitmap.blit(m_sprite, xx, yy, 0, 0, 24, 24);
+}
\ No newline at end of file
diff --git a/train.h b/train.h
new file mode 100644
index 0000000..249d92e
--- /dev/null
+++ b/train.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#include "bitmap.h"
+
+enum CarDirection {
+	North,
+	East,
+	South,
+	West
+};
+
+class Level;
+
+class TrainCar {
+public:
+	TrainCar(int x, int y) 
+		: x(x), y(y), m_sprite("car.png") {}
+
+	void update(Level&);
+	void draw(Bitmap&, int, int);
+
+	int x, y;
+private:
+	Bitmap m_sprite;
+	int m_progress;
+	CarDirection m_dir;
+};
\ No newline at end of file