Ray casting now working

camera.cpp

@@ -49,7 +49,7 @@ static void drawRays(Camera* camera, sf::RenderWindow* window)
 
 		float distance = level_rayCastDistance(camera->pos, rayDirection);
 
-		drawLine(window, camera->pos, rayDirection, distance, sf::Color::Blue);
+		drawLine(window, camera->pos, rayDirection, distance, sf::Color(150, 150, 100));
 
 		if ((i + isOddResolution) % 2) rayDirectionOffset += rayDirectionStep;
 	}

level.cpp

@@ -10,17 +10,17 @@ static void drawGrid();
 static void drawGridLine(unsigned int step, bool isHorizontal);
 static sf::Vertex getGridLineVertex(unsigned int n, unsigned int maxDimension, bool isStart, bool isHorizontal);
 
-static void castRay(sf::Vector2f point, float direction);
+static float castRay(sf::Vector2f point, float direction);
 static void getGridIndex(sf::Vector2f point, int* x, int* y);
 
 static sf::RenderWindow* window = nullptr;
 
 static unsigned int level[WIDTH * HEIGHT] = {
 	1, 1, 1, 1, 1,
-	1, 0, 0, 0, 0,
+	0, 0, 0, 0, 0,
-	1, 0, 1, 0, 1,
+	0, 0, 1, 0, 1,
-	1, 0, 0, 0, 0,
+	0, 0, 0, 0, 0,
-	1, 0, 1, 0, 1,
+	0, 0, 1, 0, 1,
 };
 
 int level_init(sf::RenderWindow* renderWindow)
@@ -45,8 +45,7 @@ void level_end()
 
 float level_rayCastDistance(sf::Vector2f point, float direction)
 {
-	castRay(point, direction);
+	return castRay(point, direction);
-	return 1000.f;
 }
 
 static void drawGrid()
@@ -107,73 +106,97 @@ static sf::Vertex getGridLineVertex(unsigned int offset, unsigned int maxDimensi
 	return isStart? start : end;
 }
 
-static void castRay(sf::Vector2f point, float direction)
+static float castRay(sf::Vector2f point, float direction)
 {
 	const sf::Vector2u windowSize = window->getSize();
 	const unsigned int tileWidth = windowSize.x/WIDTH;
 	const unsigned int tileHeight = windowSize.y/HEIGHT;
 
-	// dx and dy are the delta x and delta y of closest grid intersection
 	int indexX, indexY;
-	float dx, dy;
-
 	getGridIndex(point, &indexX, &indexY);
 
-	direction = maths_modulo(direction, 2.0f*PI);
+	// The horizontal* and vertical* variables correspond to variables, that
+	// are used to calculate the horizontal and vertical grid intersection points
+	// respectively. The horizontal and vertical grid intersections are done 
+	// separately.
+	// 
+	// The *Dy and *Dx variables are the deltas to the nearest grid boundary.
+	//
+	// The *StepX and *StepY variables are the regular x and y steps from the 
+	// initial boundary intersection along the ray.
+	//
+	// The *ProjectedX and *ProjectedY variables are projected coordinates of the 
+	// grid intersections along the ray.
+	// 
+	// The *DistCoeff variables store the coefficient of sin(direction) used to 
+	// calculate distance travelled along the ray, without having to do extra
+	// calls to sin(), as the direction doesn't change.
+	direction = maths_modulo(direction, 2.0f*PI); // modulo to keep the angle between 0 and 2 PI radians
 	bool goingDown = direction < PI;
 	int signDown = goingDown? 1 : -1;
 
-	dy = (float)((indexY + goingDown) * tileHeight) - point.y;
+	float horizontalDy = (float)((indexY + goingDown) * tileHeight) - point.y;
-	dx = dy/tan(direction);
+	float horizontalDx = horizontalDy/tan(direction);
 
 	float horizontalStepX = (float)(signDown * (tileWidth/tan(direction)));
 	float horizontalStepY = (float)(signDown * (int)tileHeight);
-	float horizontalProjectedX = point.x + dx;
+	float horizontalProjectedX = point.x + horizontalDx;
 	float horizontalProjectedY = (indexY + goingDown) * tileHeight;
 
-	direction = maths_modulo(direction + 0.5f*PI, 2.0f*PI);
+	float horizontalDistCoeff = sin(direction);
+	float horizontalRayDist = std::abs(horizontalDy/horizontalDistCoeff);
+
+	direction = maths_modulo(direction + 0.5f*PI, 2.0f*PI); // rotate angle by 90 degrees for ease of calaculation
 	bool goingRight = direction < PI;
 	int signRight = goingRight? 1 : -1;
 
-	dx = (float)((indexX + goingRight) * tileWidth) - point.x;
+	float verticalDx = (float)((indexX + goingRight) * tileWidth) - point.x;
-	dy = -dx/tan(direction);
+	float verticalDy = -verticalDx/tan(direction); // y axis needs to be flipped 
 
-	float verticalStepY = -(float)(signRight * (tileHeight/tan(direction)));
+	float verticalStepY = -(float)(signRight * (tileHeight/tan(direction))); // y axis also flipped here
 	float verticalStepX = (float)(signRight * (int)tileHeight);
-	float verticalProjectedY = point.y + dy;
+	float verticalProjectedY = point.y + verticalDy;
 	float verticalProjectedX = (indexX + goingRight) * tileWidth;
 
-	bool inLevel; 
+	float verticalDistCoeff = sin(direction);
-	do {
+	float verticalRayDist = std::abs(verticalDx/verticalDistCoeff);
-		const float circleRadius = 3.f;
-		sf::CircleShape circle(circleRadius);
 
-		circle.setFillColor(sf::Color::Red);
+	while (true) {
-
+		int indexX0, indexY0; // store grid indices for horizontal intersections
-		circle.setPosition(sf::Vector2f(horizontalProjectedX, horizontalProjectedY));
+		int indexX1, indexY1; // store grid indices for vertical intersections
-		circle.setOrigin(circleRadius, circleRadius);
-		window->draw(circle);
-
-		circle.setPosition(sf::Vector2f(verticalProjectedX, verticalProjectedY));
-		circle.setOrigin(circleRadius, circleRadius);
-		window->draw(circle);
-
-		horizontalProjectedX += horizontalStepX;
-		horizontalProjectedY += horizontalStepY;
-
-		verticalProjectedX += verticalStepX;
-		verticalProjectedY += verticalStepY;
-
-		int indexX0, indexY0;
-		int indexX1, indexY1;
 		getGridIndex(sf::Vector2f(horizontalProjectedX, horizontalProjectedY), &indexX0, &indexY0);
 		getGridIndex(sf::Vector2f(verticalProjectedX,   verticalProjectedY),   &indexX1, &indexY1);
 
-		bool inLevel0 = ((indexX0 >= 0 && indexX0 < WIDTH) && (indexY0 >= 0 && indexY0 < HEIGHT));
+		// If the ray going up or to left, the intersection points will give an index 
-		bool inLevel1 = ((indexX1 >= 0 && indexX1 < WIDTH) && (indexY1 >= 0 && indexY1 < HEIGHT));
+		// of the cells below or to the right of the cell boundaries. For those cases, 
+		// the appropriate indices will be reduced by one.
+		indexY0 -= !goingDown;
+		indexX1 -= !goingRight;
 
-		inLevel = inLevel0 || inLevel1;
+		bool inLevel0 = indexX0 != -1 && indexY0 != -1;
-	} while (inLevel);
+		bool inLevel1 = indexX1 != -1 && indexY1 != -1;
+
+		if (!(inLevel0 || inLevel1)) break; 
+
+		if (horizontalRayDist < verticalRayDist) {
+			if (level[indexY0 * WIDTH + indexX0]) return horizontalRayDist;
+
+			horizontalProjectedX += horizontalStepX;
+			horizontalProjectedY += horizontalStepY;
+
+			horizontalRayDist += std::abs(horizontalStepY/horizontalDistCoeff);
+		}
+		else {
+			if (level[indexY1 * WIDTH + indexX1]) return verticalRayDist;
+
+			verticalProjectedX += verticalStepX;
+			verticalProjectedY += verticalStepY;
+
+			verticalRayDist += std::abs(verticalStepX/verticalDistCoeff);
+		}
+	};
+
+	return 1000.f;
 }
 
 static void getGridIndex(sf::Vector2f point, int* x, int* y)

view.cpp

@@ -12,7 +12,7 @@ static sf::Uint32 style = sf::Style::Titlebar;
 static sf::RenderWindow window(sf::VideoMode(500, 500), "Raycasting", style);
 static sf::Clock timer;
 
-static Camera camera = { sf::Vector2f(300.f, 250.f), 0.f, 50, 2.0f*PI };
+static Camera camera = { sf::Vector2f(300.f, 250.f), 0.f, 100, 2.0f*PI };
 
 int view_init()
 {