Implement moving the player

Player: Add rotation and linear speeds, as well as their current state.
Player: Allow to move in the local coordinates and compute
    world-speed equivalent.
Player: Update movement axis while rotating.

World: Add a function to advance a step.
Main: Handle key events, add world step in the main loop.

Player.cpp

@@ -14,15 +14,32 @@ void Player::move(float dx, float dy)
     y += dy;
 }
 
-void Player::rotate(int alpha)
+void Player::rotate(float alpha)
 {
-    orientation += alpha%360;
+    orientation += fmodf(alpha, 360);
-    if(orientation >= 360)
+    if(orientation > 360)
     {
         orientation -= 360;
     }
-    if(orientation <= 360)
+    else if(orientation < 0)
     {
         orientation += 360;
     }
+
+	/*
+	 * Rotate the movement vector along the new angle, assumes that the only
+	 * speed influencing the player is its own movement.
+	 */
+	float prevSpeedX = currentMoveSpeedX;
+	float prevSpeedY = currentMoveSpeedY;
+	currentMoveSpeedX = cosf(-alpha * deg_to_rad) * prevSpeedX
+					    - sinf(-alpha * deg_to_rad) * prevSpeedY;
+	currentMoveSpeedY = sinf(-alpha * deg_to_rad) * prevSpeedX
+					    + cosf(-alpha * deg_to_rad) * prevSpeedY;
+}
+
+void Player::updateSpeed(float localX, float localY) {
+	// TODO: Support strafing.
+	currentMoveSpeedX = localX * sinf(orientation*deg_to_rad)*moveSpeed;
+	currentMoveSpeedY = localX * cosf(orientation*deg_to_rad)*moveSpeed;
 }

Player.h

@@ -5,6 +5,9 @@
 #ifndef RAYCASTING_PLAYER_H
 #define RAYCASTING_PLAYER_H
 
+#include <cmath>
+
+static constexpr float deg_to_rad = 3.14159265/180;
 
 class Player {
 public:
@@ -14,10 +17,22 @@ public:
     float y;
     float orientation;
 
+    float moveSpeed = 5;
+    float rotationSpeed = 180;
+
+    float currentMoveSpeedX = 0;
+    float currentMoveSpeedY = 0;
+
+    float currentRotationSpeed = 0;
+
+    /* View properties. */
     float fov = 70;
+    float sensorSize = 0.035; /* 35mm, about equivalent to human eye ? */
+    float focalLength = sensorSize / (2*tanf((fov*deg_to_rad)/2));
 
     void move(float dx, float dy);
-    void rotate(int alpha);
+    void rotate(float alpha);
+    void updateSpeed(float localX, float localY);
 };
 
 

World.cpp

@@ -3,6 +3,7 @@
 //
 
 #include "World.h"
+#include <cmath>
 
 
 World::World(int w, int h, sf::Color groundColor, sf::Color ceilingColor, std::vector<BlockType> worldMap) : w(w), h(h),
@@ -92,32 +93,119 @@ void World::fillColumn(sf::RenderWindow& window, int column, float scale, sf::Co
     window.draw(pixelColumn);
 }
 
-float World::castRay(float originX, float originY, float orientation)
+float World::castRay(float originX, float originY, float orientation) const
 {
     /*
      * Reference used for ray intersection computations :
      * https://web.archive.org/web/20220628034315/https://yunes.informatique.univ-paris-diderot.fr/wp-content/uploads/cours/INFOGRAPHIE/08-Raycasting.pdf
+     * The logic is as follows :
+     *  - This computes one set of point per edge crossings (horizontal/vertical)
+     *  - The origin not being confined to the grid, offsets are computed to
+     *    align the intersections properly
+     *  - The intersections are at multiples of the tangent of the relevant
+     *    angle for the axis of interest, and simply on successive edges of
+     *    the grid for the other one
+     *  - Depending on the orientation, signs must be taken into account
+     *    to work 360°
      */
-    float deltaX;
+    /* Offsets to get back on the grid from the ray's origin. */
-    float deltaY;
+    float hOffsetX;
-    if(orientation < 45 || orientation > 315)
+    float hOffsetY;
-    {
+    float vOffsetX;
+    float vOffsetY;
 
+    /* Signs controlling the direction of travel. */
+    float hDir;
+    float vDir;
+    /* Need offset for rounding in the right direction ? */
+    float hRound;
+    float vRound;
+
+    float rads = orientation * deg_to_rad;
+    /* Used for vertical intersections. */
+    float rads_offset = (90 - orientation) * deg_to_rad;
+
+    /* Tangents used for the different axes. */
+    float hTan = tanf(rads);
+    float vTan = tanf(rads_offset);
+
+    /* Check if cos > 0 for horizontal hits formulas. */
+    if (orientation < 90 || orientation > 270) {
+        hOffsetX = ceilf(originY) - originY;
+        hOffsetY = ceilf(originY);
+        hDir = +1;
+        hRound = 0;
+    } else {
+        hOffsetX = originY - floorf(originY);
+        hOffsetY = floorf(originY);
+        hDir = -1;
+        hRound = -1;
     }
-    else if(orientation < 135)
+    hTan *= hDir;
-    {
+    hOffsetX *= hTan;
 
+    /* Check if sin > 0 for vertical hits formulas. */
+    if (orientation < 180) {
+        vOffsetX = ceilf(originX);
+        vOffsetY = ceilf(originX) - originX;
+        vDir = +1;
+        vRound = 0;
+    } else {
+        vOffsetX = floorf(originX);
+        vOffsetY = originX - floorf(originX);
+        vDir = -1;
+        vRound = -1;
     }
-    else if(orientation < 225)
+    vTan *= vDir;
-    {
+    vOffsetY *= vTan;
-
-    }
-    else
-    {
 
+    /*
+     * Now we have all the constants and deltas to work with, cast the ray.
+     * Generated points follow the formulas :
+     *  - h-intersect : (originX + hOffsetX + hTan*i, hOffsetY + hDir*i)
+     *  - v-intersect : (vOffsetX + vDir*i, originY + vOffsetY + vTan*i)
+     */
+    int i = 0;
+    float hCheckX = originX + hOffsetX;
+    float hCheckY = hOffsetY;
+    /* Bounds + sanity check. */
+    while (hCheckX >= 0 && hCheckX <= w && hCheckY >= 0 && hCheckY <= h && i < h) {
+        if (getBlock(floorf(hCheckX), floorf(hCheckY) + hRound) == BlockType::WALL) {
+            break;
         }
 
-    return 0;
+        hCheckX += hTan;
+        hCheckY += hDir;
+        i++;
+    }
+
+    i = 0;
+    float vCheckX = vOffsetX;
+    float vCheckY = originY + vOffsetY;
+
+    /* Bounds + sanity check. */
+    while (vCheckX >= 0 && vCheckX < w && vCheckY >= 0 && vCheckY < h && i < w) {
+        if (getBlock(floorf(vCheckX) + vRound, floorf(vCheckY)) == BlockType::WALL) {
+            break;
+        }
+
+        vCheckX += vDir;
+        vCheckY += vTan;
+        i++;
+    }
+
+    /*
+     * We may or may not have hit something. Check which coordinates are closest
+     * and use those for computing the apparent size on screen.
+     */
+    float hDist = sqrtf((originX - hCheckX)*(originX - hCheckX) +
+                        (originY - hCheckY)*(originY - hCheckY));
+    float vDist = sqrtf((originX - vCheckX)*(originX - vCheckX) +
+                        (originY - vCheckY)*(originY - vCheckY));
+    float finalDist = hDist > vDist ? vDist : hDist;
+
+    /* 2 Is wall height in meters. */
+    return player.focalLength*2/finalDist;
 }
 
 void World::render(sf::RenderWindow& window) const
@@ -143,7 +231,25 @@ void World::render(sf::RenderWindow& window) const
      */
     for(int i = 0;i<window.getSize().x;i++)
     {
-        fillColumn(window, i, 0.5);
+        float deltaAngle = (player.fov/window.getSize().x) * (i-window.getSize().x/2.0);
+        float rayAngle = player.orientation + deltaAngle;
+        if (rayAngle < 0) {
+            rayAngle += 360;
+        } else if (rayAngle > 360) {
+            rayAngle -= 360;
+        }
+        float obstacleScale = castRay(player.x, player.y, rayAngle)/player.sensorSize;
+        fillColumn(window, i, obstacleScale);
     }
-
+}
+
+void World::step(const float& stepTime) {
+    player.move(player.currentMoveSpeedX*stepTime,
+                player.currentMoveSpeedY*stepTime);
+	/* Undo last move if the player would end up in a wall. */
+	if (getBlock((int)player.x, (int)player.y) != BlockType::AIR) {
+		player.move(-player.currentMoveSpeedX*stepTime,
+					-player.currentMoveSpeedY*stepTime);
+	}
+    player.rotate(player.currentRotationSpeed*stepTime);
 }

World.h

@@ -23,16 +23,24 @@ class World {
 public:
     Player player;
 
-    World(int w, int h, sf::Color groundColor = sf::Color::Green, sf::Color ceilingColor = sf::Color::Blue,
+    World(int w, int h,
+          sf::Color groundColor = sf::Color{67, 137, 39},
+          sf::Color ceilingColor = sf::Color{39, 69, 137},
           std::vector<BlockType> worldMap = {});
     int getW() const;
     int getH() const;
 
-    BlockType getBlock(float x, float y) const;
+    inline BlockType getBlock(float x, float y) const;
     void setBlock(BlockType block, int x, int y, int width = 1, int height = 1);
 
     void render(sf::RenderWindow&) const;
 
+    /**
+     * Move the world one step forward.
+     * @param stepTime delta time since last step, in seconds
+     */
+    void step(const float& stepTime);
+
     friend std::ostream& operator<<(std::ostream& ostream, World const & world);
 private:
     int w;
@@ -42,15 +50,16 @@ private:
     sf::Color groundColor;
     sf::Color ceilingColor;
 
-    void fillColumn(sf::RenderWindow&, int column, float scale, sf::Color wallColor = sf::Color(127,127,127)) const;
+    void fillColumn(sf::RenderWindow&, int column, float scale,
+                    sf::Color wallColor = sf::Color(84,56,34)) const;
     /**
      * Cast a ray from a given position and return the on-screen scale.
-     * @param originX Ray X origin
+     * @param originX Ray X origin, strictly positive
-     * @param originY Ray Y origin
+     * @param originY Ray Y origin, strictly positive
-     * @param orientation Angle to cast to, in degrees
+     * @param orientation Angle to cast to, in degrees between 0 and 360
      * @return Scale on the screen of the hit wall.
      */
-    float castRay(float originX, float originY, float orientation);
+    float castRay(float originX, float originY, float orientation) const;
 };
 
 

main.cpp

@@ -1,22 +1,12 @@
 #include <iostream>
-#include "SFML/Graphics.hpp"
+#include <SFML/Graphics.hpp>
 
 #include "World.h"
 
-// TODO: Handle inputs to move player
-// TODO: Raycast from player position
-// TODO: Fix raycasts and use it correctly
-// TODO: Render world in event loop
-// TODO: Understand what the code was doing (looks like scale from fill column is the output of the raycast)
-// Ref: https://lodev.org/cgtutor/raycasting.html
-// Ref: http://yunes.informatique.univ-paris-diderot.fr/wp-content/uploads/cours/INFOGRAPHIE/08-Raycasting.pdf
-// TODO: Update player for camera plane
-// TODO: Camera plane represents screen, rays go through it proportional to the screen
 // TODO: Find a way to go to edges instead of just equally split (?)
 
 int main()
 {
-    std::cout << "Hello, World!" << std::endl;
     World world(10,10);
     world.setBlock(BlockType::AIR,1,1,8,8);
     world.setBlock(BlockType::WALL,4,4,2,2);
@@ -27,15 +17,56 @@ int main()
     world.render(window);
     window.display();
 
+    sf::Event event{};
+    sf::Clock frameTime;
     while (window.isOpen())
     {
-        sf::Event event;
         while (window.pollEvent(event))
         {
             if (event.type == sf::Event::Closed)
                 window.close();
+            else if (event.type == sf::Event::KeyPressed) {
+                switch (event.key.code) {
+                    case sf::Keyboard::Key::Escape:
+                        window.close();
+                        break;
+                    case sf::Keyboard::Key::Left:
+                        world.player.currentRotationSpeed = -world.player.rotationSpeed;
+                        break;
+                    case sf::Keyboard::Key::Right:
+                        world.player.currentRotationSpeed = world.player.rotationSpeed;
+                        break;
+					case sf::Keyboard::Key::Up:
+						world.player.updateSpeed(1, 0);
+						break;
+					case sf::Keyboard::Key::Down:
+						world.player.updateSpeed(-1, 0);
+						break;
+                    default:
+                        break;
                 }
             }
+            else if (event.type == sf::Event::KeyReleased) {
+                switch (event.key.code) {
+                    case sf::Keyboard::Key::Left:
+                    case sf::Keyboard::Key::Right:
+                        world.player.currentRotationSpeed = 0;
+                        break;
+					case sf::Keyboard::Key::Up:
+					case sf::Keyboard::Key::Down:
+						world.player.updateSpeed(0, 0);
+						break;
+                    default:
+                        break;
+                }
+            }
+        }
+        window.clear();
+
+        world.step(frameTime.restart().asSeconds());
+        world.render(window);
+        window.display();
+    }
 
     return 0;
 }