From f2f8ccc1c24ab372ffe5e932780eeb1c49a4d277 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Fri, 21 Feb 2020 05:10:13 +0100
Subject: Add third person camera (orbit camera)

---
 src/ThirdPersonCamera.cpp | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/ThirdPersonCamera.cpp

(limited to 'src/ThirdPersonCamera.cpp')

diff --git a/src/ThirdPersonCamera.cpp b/src/ThirdPersonCamera.cpp
new file mode 100644
index 0000000..2404daf
--- /dev/null
+++ b/src/ThirdPersonCamera.cpp
@@ -0,0 +1,58 @@
+#include "../include/ThirdPersonCamera.hpp"
+#include <glm/gtc/type_ptr.hpp>
+#include <stdio.h>
+
+#define HALF_PI 1.5707963267948966f
+#define PI 3.141592653589793f
+#define TAU 6.283185307179586f
+
+namespace amalgine {
+    ThirdPersonCamera::ThirdPersonCamera() : target_pos(glm::vec3()), camera_distance(3.0f), angle_horizontal(0.0f), angle_vertical(0.0f) {
+
+    }
+
+    void ThirdPersonCamera::zoom(float distance) {
+        camera_distance += distance;
+        if(camera_distance < 0.1f)
+            camera_distance = 0.1f;
+    }
+
+    void ThirdPersonCamera::rotate_horizontal(float radians) {
+        angle_horizontal = std::fmod(angle_horizontal + radians, TAU);
+    }
+
+    void ThirdPersonCamera::rotate_vertical(float radians) {
+        const float max_angle = 1.56079632679f;
+
+        angle_vertical = std::fmod(angle_vertical + radians, TAU);
+        if(angle_vertical > max_angle)
+            angle_vertical = max_angle;
+        else if(angle_vertical < -max_angle)
+            angle_vertical = -max_angle;
+    }
+
+    void ThirdPersonCamera::set_target_position(const glm::vec3 &target_pos) {
+        this->target_pos = target_pos;
+    }
+
+    glm::mat4 ThirdPersonCamera::get_matrix() const {
+        glm::vec3 eye = target_pos - get_forward_vector() * camera_distance;
+        return glm::lookAt(eye, target_pos, glm::vec3(0.0f, 0.0f, 1.0f));
+    }
+
+    glm::vec3 ThirdPersonCamera::get_forward_vector() const {
+        glm::vec3 vec;
+        vec.x = std::sin(angle_horizontal) * std::cos(angle_vertical);
+        vec.y = std::cos(angle_horizontal) * std::cos(angle_vertical);
+        vec.z = std::sin(angle_vertical);
+        return vec;
+    }
+
+    glm::vec3 ThirdPersonCamera::get_right_vector() const {
+        glm::vec3 vec = get_forward_vector();
+        float temp = vec.x;
+        vec.x = vec.y;
+        vec.y = -temp;
+        return vec;
+    }
+}
\ No newline at end of file
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