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Camera.h

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+#ifndef CAMERA_CLASS_H
+#define CAMERA_CLASS_H
+#include <algorithm>
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
+#include <glm/gtc/quaternion.hpp>
+#include <cmath>
+#include <cstdlib>
+#include "common.h"
+#include "Window.h"
+#include "t.h"
+#include "tFunctions.h"
+#include "shaderClass.h"
+
+const glm::vec3 worldUp = { 0.0f, 1.0f, 0.0f };
+
+// Default mouse sensitivity in cm of mouse travel per 360 degree turn.
+inline float StartupCmPer360 = 16.0f;
+inline float StartupMouseDpi = 800.0f;
+
+class Camera {
+public:
+    bool  lockedcursor = true;
+    t     t;
+    float yaw = 0.0f;
+    float pitch = 0.0f;
+    const float originalspeed = 0.08f;
+    float speed = 0.08f;
+    float sensitivity = 0.001f;
+    float FOV = 110.0f;
+    float screenshake = 0.0f;           // 0 still to 1 shaking as hard as it does, wearing off over time
+    float shakeDecay = 1.2f;            // of full strength lost a second of game time
+    glm::vec3 shakeMaxAngles = glm::vec3(0.08f, 0.08f, 0.04f);   // radians of pitch, yaw and roll at full strength
+
+    Camera() {
+        if (StartupCmPer360 > 0.0f) SetSensitivityCm(StartupCmPer360, StartupMouseDpi);
+    }
+
+    // Turn sensitivity into "this many cm of mouse travel per full 360 degree turn" for a mouse
+    // of the given DPI (mouse counts per inch).
+    void SetSensitivityCm(float cmPer360, float dpi) {
+        sensitivity = 6.2831853f / (cmPer360 / 2.54f * dpi);
+    }
+
+    // Shakes the camera, amount of full strength on top of whatever shake there already is. Around 0.3 for a hit,
+    // 1 for something huge.
+    void AddScreenshake(float amount) {
+        screenshake = std::min(screenshake + amount, 1.0f);
+    }
+
+    void Matrix(float nearPlane, float farPlane, Shader& shader) {
+        shader.SetMat4("proj", GetProjectionMatrix(nearPlane, farPlane));
+        shader.SetMat4("view", GetViewMatrix());
+        shader.Set3F("viewPos", t.GetTranslation());
+    }
+
+    glm::mat4 GetViewMatrix() {
+        glm::vec3 front = t.GetFrontVector();
+        glm::vec3 up = t.GetUpVector();
+
+        if (screenshake > 0.0f) {
+            // Apply smooth shake offset stored in shakeOffset
+            glm::quat offsetRot = glm::quat(glm::vec3(
+                shakeOffset.x,
+                shakeOffset.y,
+                shakeOffset.z   // roll
+            ));
+            front = glm::normalize(offsetRot * front);
+            up = glm::normalize(offsetRot * up);
+        }
+
+        return glm::lookAt(t.GetTranslation(), t.GetTranslation() + front, up);
+    }
+
+    glm::mat4 GetProjectionMatrix(float nearPlane, float farPlane) {
+        // Quake Pro style: FOV is the horizontal angle on a 4:3 screen, so the vertical angle is fixed
+        // and wider windows/fullscreen reveal more to the sides instead of zooming in.
+        const float aspect = (float)window->width / (float)window->height;
+        const float vfov = 2.0f * atan(tan(glm::radians(FOV) * 0.5f) * 3.0f / 4.0f);
+        return glm::perspective(vfov, aspect, nearPlane, farPlane);
+    }
+
+    void Step(float dt) {
+        if (screenshake <= 0.0f) {
+            shakeOffset = glm::vec3(0.0f);
+            return;
+        }
+
+        // A smooth wobble on each axis, out of step with each other, scaled by how strong the shake still is
+        shakeTime += dt;
+        auto Wobble = [&](float seed) {
+            return (std::sin(shakeTime * 31.0f + seed) + std::sin(shakeTime * 57.3f + seed * 2.7f)) * 0.5f;
+        };
+        shakeOffset = shakeMaxAngles * screenshake * glm::vec3(Wobble(0.0f), Wobble(11.0f), Wobble(23.0f));
+
+        screenshake = std::max(screenshake - shakeDecay * dt, 0.0f);
+    }
+
+    // Back to looking where the mouse last had it, after something else has turned the camera
+    void RestoreLook() {
+        t.RotateToEulerAngles({ pitch, yaw, 0.0f });
+        t.NormalizeRotation();
+    }
+
+    void ProcessMouseMovement(float xoffset, float yoffset) {
+        xoffset *= sensitivity;
+        yoffset *= sensitivity;
+        yaw += xoffset;
+        pitch += yoffset;
+        pitch = glm::clamp(pitch, -glm::radians(85.0f), glm::radians(85.0f));
+        t.RotateToEulerAngles({ pitch, yaw, 0.0f });
+        t.NormalizeRotation();
+    }
+
+private:
+    glm::vec3 shakeOffset = glm::vec3(0.0f);  // this frame's turn from shaking, pitch, yaw and roll
+    float     shakeTime = 0.0f;               // runs the wobble along
+};
+
+#endif