Implementing Rotation of the camera by mouse input

client/src/main/java/core/engine/Engine.java

@@ -8,12 +8,14 @@ import core.engine.model.TexturedModel;
 import core.engine.renderer.MasterRenderer;
 import core.engine.terrain.Terrain;
 import core.engine.textures.ModelTexture;
+import org.lwjgl.BufferUtils;
 import org.lwjgl.Version;
 import org.lwjgl.glfw.*;
 import org.lwjgl.opengl.GL;
 import org.lwjgl.system.MemoryStack;
 import utils.vectors.Vector3f;
 
+import java.nio.DoubleBuffer;
 import java.nio.IntBuffer;
 
 import static org.lwjgl.glfw.Callbacks.glfwFreeCallbacks;
@@ -30,6 +32,10 @@ public class Engine {
     private final Loader loader = new Loader();
     public static int WINDOW_WIDTH = 1280;
     public static int WINDOW_HEIGHT = 720;
+    private static boolean isMouseWheelPressed = false;
+    private static DoubleBuffer lastCursorX = BufferUtils.createDoubleBuffer(1);
+    private static DoubleBuffer lastCursorY = BufferUtils.createDoubleBuffer(1);
+
 
     public Engine() {
 
@@ -112,41 +118,7 @@ public class Engine {
         glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
         Camera camera = new Camera();
 
-        GLFWScrollCallback glfwScrollCallback = new GLFWScrollCallback() {
+        input(camera);
-            @Override
-            public void invoke(long window, double xOffset, double yOffset) {
-                if(yOffset > 0) {
-                    camera.zoomIn();
-                } else if(yOffset < 0) {
-                    camera.zoomOut();
-                }
-            }
-        };
-
-        glfwSetScrollCallback(window, glfwScrollCallback);
-        glfwSetKeyCallback(window, glfwKeyCallback = new GLFWKeyCallback() {
-            @Override
-            public void invoke(long window, int key, int scancode, int action, int mods) {
-                if(key == GLFW_KEY_A) {
-                    //move camera to left
-                    camera.moveLeft();
-                }
-
-                if(key == GLFW_KEY_D) {
-                    //move camera to right
-                    camera.moveRight();
-                }
-
-                if(key == GLFW_KEY_W) {
-                    camera.moveForward();
-                }
-
-                if(key == GLFW_KEY_S) {
-                    camera.moveBackward();
-                }
-            }
-        });
-
 
         Light light = new Light(new Vector3f(0,0,-20), new Vector3f(1,1,1));
         RawModel model = OBJLoader.loadOBJModel("dragon", loader);
@@ -177,4 +149,89 @@ public class Engine {
         loader.cleanUp();
     }
 
+    private void input(Camera camera) {
+
+        GLFWScrollCallback glfwScrollCallback = new GLFWScrollCallback() {
+            @Override
+            public void invoke(long window, double xOffset, double yOffset) {
+                if(yOffset > 0) {
+                    camera.zoomIn();
+                } else if(yOffset < 0) {
+                    camera.zoomOut();
+                }
+            }
+        };
+
+        GLFWMouseButtonCallback glfwMouseButtonCallback = new GLFWMouseButtonCallback() {
+            @Override
+            public void invoke(long window, int button, int action, int mods) {
+                if (button == GLFW.GLFW_MOUSE_BUTTON_MIDDLE && action == GLFW.GLFW_PRESS) {
+                    // Middle mouse button pressed
+                    isMouseWheelPressed = true;
+                    glfwGetCursorPos(window, lastCursorX, lastCursorY);
+                } else if (button == GLFW.GLFW_MOUSE_BUTTON_MIDDLE && action == GLFW.GLFW_RELEASE) {
+                    // Middle mouse button released
+                    isMouseWheelPressed = false;
+                }
+            }
+        };
+
+        // Define the cursor position callback function
+        GLFWCursorPosCallback cursorPosCallback = new GLFWCursorPosCallback() {
+            @Override
+            public void invoke(long window, double xpos, double ypos) {
+                if (isMouseWheelPressed) {
+                    // Calculate the offset
+                    double xOffset = xpos - lastCursorX.get(0);
+                    double yOffset = ypos - lastCursorY.get(0);
+
+                    // Use xOffset and yOffset for your desired functionality
+                    if(yOffset > 0) {
+                        camera.decreasePitch();
+                    } else if(yOffset < 0) {
+                        camera.increasePitch();
+                    }
+
+                    if(xOffset > 0) {
+                        camera.decreaseYaw();
+                    } else if(xOffset < 0) {
+                        camera.increaseYaw();
+                    }
+
+                    // Update the last cursor position
+                    lastCursorX.put(0, xpos);
+                    lastCursorY.put(0, ypos);
+                }
+            }
+        };
+
+        glfwSetMouseButtonCallback(window, glfwMouseButtonCallback);
+        glfwSetCursorPosCallback(window, cursorPosCallback);
+
+        glfwSetScrollCallback(window, glfwScrollCallback);
+        glfwSetKeyCallback(window, glfwKeyCallback = new GLFWKeyCallback() {
+            @Override
+            public void invoke(long window, int key, int scancode, int action, int mods) {
+                if(key == GLFW_KEY_A) {
+                    //move camera to left
+                    camera.moveLeft();
+                }
+
+                if(key == GLFW_KEY_D) {
+                    //move camera to right
+                    camera.moveRight();
+                }
+
+                if(key == GLFW_KEY_W) {
+                    camera.moveForward();
+                }
+
+                if(key == GLFW_KEY_S) {
+                    camera.moveBackward();
+                }
+            }
+        });
+
+    }
+
 }

client/src/main/java/core/engine/entity/Camera.java

@@ -33,6 +33,22 @@ public class Camera {
         position.y -= 0.5f;
     }
 
+    public void increasePitch() {
+        this.pitch += .5f;
+    }
+
+    public void decreasePitch() {
+        this.pitch -= .5f;
+    }
+
+    public void increaseYaw() {
+        this.yaw += 0.5f;
+    }
+
+    public void decreaseYaw() {
+        this.yaw -= 0.5f;
+    }
+
     public Vector3f getPosition() {
         return position;
     }
@@ -48,4 +64,16 @@ public class Camera {
     public float getRoll() {
         return roll;
     }
+
+    public void setPitch(float pitch) {
+        this.pitch += pitch;
+    }
+
+    public void setYaw(float yaw) {
+        this.yaw += yaw;
+    }
+
+    public void setRoll(float roll) {
+        this.roll += roll;
+    }
 }