Basic camera, mesh, rendering systems

Not used yet!

CMakeLists.txt

@@ -7,7 +7,7 @@ find_package(OpenGL REQUIRED)
 find_package(glfw3 REQUIRED)
 find_package(glm REQUIRED)
 
-add_executable(ecsgame Util/glad.c Util/OBJ_Loader.h Rendering/Shader.cpp Rendering/Shader.h main.cpp ECS/Components/Transform.h ECS/Components/Movement.h ECS/Events/InputEvent.h ECS/Systems/GravitySystem.h ECS/Systems/PositionDebugSystem.h ECS/Systems/KeyboardMovementSystem.h ECS/Components/Camera.h)
+add_executable(ecsgame Util/glad.c Util/OBJ_Loader.h Rendering/Shader.cpp Rendering/Shader.h main.cpp ECS/Components/Transform.h ECS/Components/Movement.h ECS/Events/InputEvent.h ECS/Systems/GravitySystem.h ECS/Systems/PositionDebugSystem.h ECS/Systems/KeyboardMovementSystem.h ECS/Components/Camera.h ECS/Systems/RenderSystem.h ECS/Components/Mesh.h)
 
 include_directories(${OPENGL_INCLUDE_DIRS})
 

ECS/Components/Camera.h

@@ -0,0 +1,19 @@
+//
+// Created by karl on 07.01.20.
+//
+
+#ifndef ECSGAME_CAMERA_H
+#define ECSGAME_CAMERA_H
+
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+
+struct Camera {
+    /// Create a camera with a field of view (in degrees), width and height (in any unit) and near and far distances
+    Camera(float fov, float width, float height, float near, float far) : projection(
+            glm::perspective(glm::radians(fov), width / height, near, far)) {}
+
+    glm::mat4 projection;
+};
+
+#endif //ECSGAME_CAMERA_H

ECS/Components/Mesh.h

@@ -0,0 +1,45 @@
+//
+// Created by karl on 07.01.20.
+//
+
+#ifndef ECSGAME_MESH_H
+#define ECSGAME_MESH_H
+
+#include <glad/glad.h>
+#include <GLFW/glfw3.h>
+#include <vector>
+
+struct Mesh {
+    explicit Mesh(std::vector<float> vertices_vector) : vertices(&vertices_vector[0]), vertex_count(vertices_vector.size()) {
+        glGenVertexArrays(1, &VAO);
+        glGenBuffers(1, &VBO);
+
+        glBindVertexArray(VAO);
+
+        glBindBuffer(GL_ARRAY_BUFFER, VBO);
+        glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+        // position attribute
+        glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
+        glEnableVertexAttribArray(0);
+
+        // texture coord attribute
+        glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
+        glEnableVertexAttribArray(1);
+    }
+
+    void render() {
+        glBindVertexArray(VAO);
+        glDrawArrays(GL_TRIANGLES, 0, vertex_count);
+    }
+
+private:
+    unsigned int VBO;
+    unsigned int VAO;
+    unsigned int vertex_count;
+
+    /// Vertices in the format x, y, z, u, v
+    float *vertices;
+};
+
+#endif //ECSGAME_MESH_H

ECS/Components/Transform.h

@@ -26,6 +26,10 @@ struct Transform {
         matrix = glm::scale(matrix, factors);
     }
 
+    void rotate(float degrees, glm::vec3 axis) {
+        matrix = glm::rotate(matrix, glm::radians(degrees), axis);
+    }
+
     glm::vec3 getPosition() {
         return matrix * glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
     }

ECS/Systems/RenderSystem.h

@@ -0,0 +1,35 @@
+//
+// Created by karl on 07.01.20.
+//
+
+#ifndef ECSGAME_RENDERSYSTEM_H
+#define ECSGAME_RENDERSYSTEM_H
+
+#include "../ECS.h"
+#include "../Components/Transform.h"
+#include "../Components/Mesh.h"
+#include "../Components/Camera.h"
+#include "../../Rendering/Shader.h"
+
+using namespace ECS;
+
+class RenderSystem : public EntitySystem {
+public:
+    void render(World *pWorld, Shader shader) {
+        pWorld->each<Camera, Transform>([&](Entity *ent, ComponentHandle<Camera> camera, ComponentHandle<Transform> camera_transform) {
+            shader.setMat4("projection", camera->projection);
+            shader.setMat4("view", camera_transform->matrix);
+
+            pWorld->each<Mesh, Transform>([&](Entity *ent, ComponentHandle<Mesh> mesh, ComponentHandle<Transform> transform) {
+                shader.setMat4("model", transform->matrix);
+
+                mesh->render();
+            });
+        });
+    }
+
+private:
+    float gravityAmount;
+};
+
+#endif //ECSGAME_RENDERSYSTEM_H

README.md

@@ -5,3 +5,5 @@ C++ ECS OpenGL game demo
 Some code adapted from Joey de Vries' (https://twitter.com/JoeyDeVriez) tutorials at https://learnopengl.com/About licensed under https://creativecommons.org/licenses/by-nc/4.0/.
 
 OBJ-Loader from https://github.com/Bly7/OBJ-Loader.
+
+ECS library from https://github.com/redxdev/ECS.

Rendering/Shader.cpp

@@ -9,6 +9,7 @@
 #include <fstream>
 #include <sstream>
 #include <iostream>
+#include <glm/gtc/type_ptr.hpp>
 
 Shader::Shader(const char *vertexPath, const char *fragmentPath) {
     // 1. retrieve the vertex/fragment source code from filePath
@@ -87,6 +88,10 @@ void Shader::setFloat(const std::string &name, float value) const {
     glUniform1f(glGetUniformLocation(ID, name.c_str()), value);
 }
 
+void Shader::setMat4(const std::string &name, glm::mat4 mat) const {
+    glUniformMatrix4fv(glGetUniformLocation(ID, name.c_str()), 10, GL_FALSE, glm::value_ptr(mat));
+}
+
 void Shader::checkCompileErrors(unsigned int shader, const std::string &type) {
     int success;
     char infoLog[1024];

Rendering/Shader.h

@@ -6,6 +6,7 @@
 #define ECSGAME_SHADER_H
 
 #include <string>
+#include <glm/glm.hpp>
 
 class Shader {
 public:
@@ -28,6 +29,9 @@ public:
     /// Set a uniform float in the shader
     void setFloat(const std::string &name, float value) const;
 
+    /// Set a uniform mat4 in the shader
+    void setMat4(const std::string &name, glm::mat4 mat) const;
+
 private:
     static void checkCompileErrors(unsigned int shader, const std::string &type);
 };

main.cpp

@@ -9,6 +9,7 @@
 #include "ECS/Systems/GravitySystem.h"
 #include "ECS/Systems/PositionDebugSystem.h"
 #include "ECS/Systems/KeyboardMovementSystem.h"
+#include "ECS/Systems/RenderSystem.h"
 
 using namespace ECS;
 
@@ -24,17 +25,6 @@ static void key_callback(GLFWwindow *window, int key, int scancode, int action,
 }
 
 int main() {
-    // TODO: Could be automated by getting all classes within 'ECS/Systems'
-    world->registerSystem(new GravitySystem(-9.8f));
-    world->registerSystem(new PositionDebugOutputSystem());
-    world->registerSystem(new KeyboardMovementSystem());
-
-    Entity *ent = world->create();
-    ent->assign<Transform>();
-    ent->assign<Movement>(glm::vec3(1.f, 1.f, 1.f));
-
-    ComponentHandle<Transform> pos = ent->get<Transform>();
-
     GLFWwindow *window;
 
     /* Initialize the library */
@@ -61,6 +51,21 @@ int main() {
         return -1;
     }
 
+    // TODO: Could be automated by getting all classes within 'ECS/Systems'
+    // world->registerSystem(new GravitySystem(-9.8f));
+    world->registerSystem(new PositionDebugOutputSystem());
+    world->registerSystem(new KeyboardMovementSystem());
+    world->registerSystem(new RenderSystem());
+
+    Entity *player = world->create();
+    player->assign<Transform>();
+    player->assign<Movement>(glm::vec3(1.f, 1.f, 1.f));
+    player->assign<Camera>(70.0f, 640, 480, 0.1f, 100.0f);
+
+    Entity *box = world->create();
+    box->assign<Transform>();
+    box->get<Transform>()->translate(glm::vec3(0.0f, 0.0f, -10.0f));
+
     Shader defaultShader("Shaders/default-vertex.vs", "Shaders/default-fragment.fs");
 
     // set up vertex data (and buffer(s)) and configure vertex attributes