Put the OpenGL to work

app/src/main/java/com/bartlomiejpluta/samplegame/App.java

@@ -5,12 +5,14 @@ package com.bartlomiejpluta.samplegame;
 
 import com.bartlomiejpluta.samplegame.core.engine.GameEngine;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.ApplicationArguments;
 import org.springframework.boot.ApplicationRunner;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
+@Slf4j
 @SpringBootApplication
 @RequiredArgsConstructor(onConstructor = @__(@Autowired))
 public class App implements ApplicationRunner {
@@ -18,6 +20,7 @@ public class App implements ApplicationRunner {
 
     @Override
     public void run(ApplicationArguments args) {
+        log.info("Starting game engine");
         gameEngine.start();
     }
 

app/src/main/java/com/bartlomiejpluta/samplegame/core/engine/DefaultGameEngine.java

@@ -1,17 +1,23 @@
 package com.bartlomiejpluta.samplegame.core.engine;
 
+import com.bartlomiejpluta.samplegame.core.logic.GameLogic;
 import com.bartlomiejpluta.samplegame.core.thread.ThreadManager;
 import com.bartlomiejpluta.samplegame.core.time.ChronoMeter;
 import com.bartlomiejpluta.samplegame.core.ui.Window;
 import com.bartlomiejpluta.samplegame.core.ui.WindowManager;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 
+@Slf4j
 @Component
 public class DefaultGameEngine implements GameEngine {
+   private static final String THREAD_NAME = "Game Main Thread";
+
    private final WindowManager windowManager;
    private final ThreadManager threadManager;
+   private final GameLogic logic;
 
    private final Thread thread;
    private final Window window;
@@ -23,16 +29,17 @@ public class DefaultGameEngine implements GameEngine {
    @Autowired
    public DefaultGameEngine(WindowManager windowManager,
                             ThreadManager threadManager,
+                            GameLogic logic,
                             @Value("${app.window.title}") String title,
                             @Value("${app.window.width}") int width,
                             @Value("${app.window.height}") int height,
                             @Value("${app.core.targetUps}") int targetUps) {
       this.windowManager = windowManager;
       this.threadManager = threadManager;
-
+      this.logic = logic;
 
       this.window = windowManager.createWindow(title, width, height);
-      this.thread = threadManager.createThread(this::run);
+      this.thread = threadManager.createThread(THREAD_NAME, this::run);
       this.chrono = new ChronoMeter();
       this.targetUps = targetUps;
    }
@@ -47,11 +54,14 @@ public class DefaultGameEngine implements GameEngine {
    }
 
    private void init() {
+      log.info("Initializing game engine");
       window.init();
       chrono.init();
+      logic.init(window);
    }
 
    private void loop() {
+      log.info("Starting game loop");
       running = true;
       var dt = 0.0f;
       var accumulator = 0.0f;
@@ -73,19 +83,20 @@ public class DefaultGameEngine implements GameEngine {
    }
 
    private void input() {
-
+      logic.input(window);
    }
 
    private void update(float dt) {
-
+      logic.update(dt);
    }
 
    private void render() {
       window.update();
+      logic.render(window);
    }
 
    private void cleanUp() {
-
+      logic.cleanUp();
    }
 
    @Override

app/src/main/java/com/bartlomiejpluta/samplegame/core/error/AppException.java

@@ -4,8 +4,8 @@ public class AppException extends RuntimeException {
    public AppException() {
    }
 
-   public AppException(String message) {
-      super(message);
+   public AppException(String message, Object... args) {
+      super(String.format(message, args));
    }
 
    public AppException(String message, Throwable cause) {

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/render/DefaultRenderer.java

@@ -0,0 +1,56 @@
+package com.bartlomiejpluta.samplegame.core.gl.render;
+
+import com.bartlomiejpluta.samplegame.core.ui.Window;
+import com.bartlomiejpluta.samplegame.core.gl.shader.manager.ShaderManager;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.lwjgl.system.MemoryStack;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import static org.lwjgl.opengl.GL15.*;
+import static org.lwjgl.opengl.GL20.glEnableVertexAttribArray;
+import static org.lwjgl.opengl.GL20.glVertexAttribPointer;
+import static org.lwjgl.opengl.GL30.glBindVertexArray;
+import static org.lwjgl.opengl.GL30.glGenVertexArrays;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor(onConstructor = @__(@Autowired))
+public class DefaultRenderer implements Renderer {
+   private final ShaderManager shaderManager;
+
+   @Override
+   public void init() {
+      log.info("Initializing renderer");
+      shaderManager.createShader("default", "/shaders/default.vs", "/shaders/default.fs");
+   }
+
+   @Override
+   public void render(Window window) {
+      clear();
+      updateViewport(window);
+
+      shaderManager.selectShader("default").useSelectedShader();
+
+      // here the objects will be rendered with the default shader
+
+      shaderManager.detachCurrentShader();
+   }
+
+   private void clear() {
+      glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+   }
+
+   private void updateViewport(Window window) {
+      if(window.isResized()) {
+         glViewport(0, 0, window.getWidth(), window.getHeight());
+         window.setResized(false);
+      }
+   }
+
+   @Override
+   public void cleanUp() {
+      shaderManager.cleanUp();
+   }
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/render/Renderer.java

@@ -0,0 +1,11 @@
+package com.bartlomiejpluta.samplegame.core.gl.render;
+
+import com.bartlomiejpluta.samplegame.core.ui.Window;
+
+public interface Renderer {
+   void init();
+
+   void render(Window window);
+
+   void cleanUp();
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/shader/manager/DefaultShaderManager.java

@@ -0,0 +1,138 @@
+package com.bartlomiejpluta.samplegame.core.gl.shader.manager;
+
+import com.bartlomiejpluta.samplegame.core.util.res.ResourcesManager;
+import com.bartlomiejpluta.samplegame.core.gl.shader.program.ShaderProgram;
+import com.bartlomiejpluta.samplegame.core.gl.shader.uniform.Uniform;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+import org.joml.Vector3f;
+import org.joml.Vector4f;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.HashMap;
+import java.util.Map;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor(onConstructor = @__(@Autowired))
+public class DefaultShaderManager implements ShaderManager {
+   private final ResourcesManager resourcesManager;
+   private final Map<String, ShaderProgram> shaders = new HashMap<>();
+   private ShaderProgram current;
+
+   @Override
+   public ShaderManager createShader(String programName, String vertexShaderFilename, String fragmentShaderFilename) {
+      log.info("Creating {} shader", programName);
+      var vertexShaderCode = resourcesManager.loadResourceAsString(vertexShaderFilename);
+      var fragmentShaderCode = resourcesManager.loadResourceAsString(fragmentShaderFilename);
+      var program = ShaderProgram.compile(vertexShaderCode, fragmentShaderCode);
+
+      shaders.put(programName, program);
+
+      return this;
+   }
+
+   @Override
+   public ShaderManager selectShader(String programName) {
+      current = shaders.get(programName);
+      return this;
+   }
+
+   @Override
+   public ShaderManager useSelectedShader() {
+      current.use();
+      return this;
+   }
+
+   @Override
+   public ShaderManager detachCurrentShader() {
+      current.detach();
+      return this;
+   }
+
+   @Override
+   public ShaderManager createUniform(String uniformName) {
+      current.createUniform(uniformName);
+      return this;
+   }
+
+   @Override
+   public ShaderManager createUniform(String uniformName, Uniform uniform) {
+      current.createUniform(uniformName, uniform);
+      return this;
+   }
+
+   @Override
+   public ShaderManager createUniforms(String uniformName, int size) {
+      current.createUniforms(uniformName, size);
+      return this;
+   }
+
+   @Override
+   public ShaderManager createUniforms(String uniformName, int size, Uniform uniform) {
+      current.createUniforms(uniformName, size, uniform);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, int value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, float value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, Vector3f value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, Vector4f value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, Matrix3f value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, Matrix4f value) {
+      current.setUniform(uniformName, value);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, Uniform uniform) {
+      current.setUniform(uniformName, uniform);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniform(String uniformName, int index, Uniform uniform) {
+      current.setUniform(uniformName, index, uniform);
+      return this;
+   }
+
+   @Override
+   public ShaderManager setUniforms(String uniformName, Uniform[] uniforms) {
+      current.setUniforms(uniformName, uniforms);
+      return this;
+   }
+
+   @Override
+   public void cleanUp() {
+      shaders.forEach((name, program) -> program.cleanUp());
+   }
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/shader/manager/ShaderManager.java

@@ -0,0 +1,57 @@
+package com.bartlomiejpluta.samplegame.core.gl.shader.manager;
+
+import com.bartlomiejpluta.samplegame.core.gl.shader.uniform.Uniform;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+import org.joml.Vector3f;
+import org.joml.Vector4f;
+
+public interface ShaderManager {
+   ShaderManager createShader(String programName, String vertexShaderFilename, String fragmentShaderFilename);
+
+   ShaderManager selectShader(String programName);
+
+   ShaderManager useSelectedShader();
+
+   ShaderManager detachCurrentShader();
+
+   ShaderManager createUniform(String uniformName);
+
+
+   ShaderManager createUniform(String uniformName, Uniform uniform);
+
+
+   ShaderManager createUniforms(String uniformName, int size);
+
+
+   ShaderManager createUniforms(String uniformName, int size, Uniform uniform);
+
+
+   ShaderManager setUniform(String uniformName, int value);
+
+
+   ShaderManager setUniform(String uniformName, float value);
+
+
+   ShaderManager setUniform(String uniformName, Vector3f value);
+
+
+   ShaderManager setUniform(String uniformName, Vector4f value);
+
+
+   ShaderManager setUniform(String uniformName, Matrix3f value);
+
+
+   ShaderManager setUniform(String uniformName, Matrix4f value);
+
+
+   ShaderManager setUniform(String uniformName, Uniform uniform);
+
+
+   ShaderManager setUniform(String uniformName, int index, Uniform uniform);
+
+
+   ShaderManager setUniforms(String uniformName, Uniform[] uniforms);
+
+   void cleanUp();
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/shader/program/ShaderProgram.java

@@ -0,0 +1,168 @@
+package com.bartlomiejpluta.samplegame.core.gl.shader.program;
+
+import com.bartlomiejpluta.samplegame.core.error.AppException;
+import com.bartlomiejpluta.samplegame.core.gl.shader.uniform.Uniform;
+import lombok.extern.slf4j.Slf4j;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+import org.joml.Vector3f;
+import org.joml.Vector4f;
+import org.lwjgl.system.MemoryStack;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static java.lang.String.format;
+import static org.lwjgl.opengl.GL20.*;
+
+@Slf4j
+public class ShaderProgram {
+   private final int programId;
+   private final int vertexShaderId;
+   private final int fragmentShaderId;
+   private final Map<String, Integer> uniforms = new HashMap<>();
+
+   private ShaderProgram(String vertexShaderCode, String fragmentShaderCode) {
+      this.programId = glCreateProgram();
+
+      if(this.programId == 0) {
+         throw new AppException("Could not create shader program");
+      }
+
+      this.vertexShaderId = createShader(vertexShaderCode, GL_VERTEX_SHADER);
+      this.fragmentShaderId = createShader(fragmentShaderCode, GL_FRAGMENT_SHADER);
+
+      linkProgram();
+   }
+
+   private int createShader(String shaderCode, int shaderType) {
+      int shaderId = glCreateShader(shaderType);
+      if(shaderId == 0) {
+         throw new AppException("Could not create shader of type: %s", shaderType);
+      }
+
+      glShaderSource(shaderId, shaderCode);
+      glCompileShader(shaderId);
+
+      if(glGetShaderi(shaderId, GL_COMPILE_STATUS) == 0) {
+         throw new AppException("Could not compile shader code: %s", glGetShaderInfoLog(shaderId, 1024));
+      }
+
+      glAttachShader(programId, shaderId);
+
+      return shaderId;
+   }
+
+   private void linkProgram() {
+      glLinkProgram(programId);
+      if(glGetProgrami(programId, GL_LINK_STATUS) == 0) {
+         throw new AppException("Could not link shader program: %s", glGetProgramInfoLog(programId, 1024));
+      }
+
+      if(vertexShaderId != 0) {
+         glDetachShader(programId, vertexShaderId);
+      }
+
+      if(fragmentShaderId != 0) {
+         glDetachShader(programId, fragmentShaderId);
+      }
+
+      glValidateProgram(programId);
+      if(glGetProgrami(programId, GL_VALIDATE_STATUS) == 0) {
+         log.warn("Program validation failed: {}", glGetProgramInfoLog(programId, 1024));
+      }
+   }
+
+   public void createUniform(String uniformName) {
+      int location = glGetUniformLocation(programId, uniformName);
+
+      if(location < 0) {
+         throw new AppException("Could not find uniform: %s", uniformName);
+      }
+
+      uniforms.put(uniformName, location);
+   }
+
+   public void createUniform(String uniformName, Uniform uniform) {
+      uniform.createUniform(this, uniformName);
+   }
+
+   public void createUniforms(String uniformName, int size) {
+      for(int i=0; i<size; ++i) {
+         createUniform(format("%s[%d]", uniformName, i));
+      }
+   }
+
+   public void createUniforms(String uniformName, int size, Uniform uniform) {
+      for(int i=0; i<size; ++i) {
+         createUniform(format("%s[%d]", uniformName, i), uniform);
+      }
+   }
+
+   public void setUniform(String uniformName, int value) {
+      glUniform1i(uniforms.get(uniformName), value);
+   }
+
+   public void setUniform(String uniformName, float value) {
+      glUniform1f(uniforms.get(uniformName), value);
+   }
+
+   public void setUniform(String uniformName, Vector3f value) {
+      glUniform3f(uniforms.get(uniformName), value.x, value.y, value.z);
+   }
+
+   public void setUniform(String uniformName, Vector4f value) {
+      glUniform4f(uniforms.get(uniformName), value.x, value.y, value.z, value.w);
+   }
+
+   public void setUniform(String uniformName, Matrix3f value) {
+      try(var stack = MemoryStack.stackPush()) {
+         var buffer = stack.mallocFloat(3 * 3);
+         value.get(buffer);
+         glUniformMatrix4fv(uniforms.get(uniformName), false, buffer);
+      }
+   }
+
+   public void setUniform(String uniformName, Matrix4f value) {
+      try(var stack = MemoryStack.stackPush()) {
+         var buffer = stack.mallocFloat(4 * 4);
+         value.get(buffer);
+         glUniformMatrix4fv(uniforms.get(uniformName), false, buffer);
+      }
+   }
+
+   public void setUniform(String uniformName, Uniform uniform) {
+      uniform.setUniform(this, uniformName);
+   }
+
+   public void setUniform(String uniformName, int index, Uniform uniform) {
+      setUniform(format("%s[%d]", uniformName, index), uniform);
+   }
+
+   public void setUniforms(String uniformName, Uniform[] uniforms) {
+      var size = uniforms != null ? uniforms.length : 0;
+      for(int i=0; i<size; ++i) {
+         setUniform(format("%s[%d]", uniformName, i), uniforms[i]);
+      }
+   }
+
+   public void use() {
+      glUseProgram(programId);
+   }
+
+   public void detach() {
+      glUseProgram(0);
+   }
+
+   public void cleanUp() {
+      glUseProgram(0);
+
+      if(programId != 0) {
+         glDeleteProgram(programId);
+      }
+   }
+
+   public static ShaderProgram compile(String vertexShaderCode, String fragmentShaderCode) {
+      return new ShaderProgram(vertexShaderCode, fragmentShaderCode);
+   }
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/gl/shader/uniform/Uniform.java

@@ -0,0 +1,9 @@
+package com.bartlomiejpluta.samplegame.core.gl.shader.uniform;
+
+import com.bartlomiejpluta.samplegame.core.gl.shader.program.ShaderProgram;
+
+public interface Uniform {
+   void createUniform(ShaderProgram shaderProgram, String uniformName);
+
+   void setUniform(ShaderProgram shaderProgram, String uniformName);
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/logic/GameLogic.java

@@ -0,0 +1,15 @@
+package com.bartlomiejpluta.samplegame.core.logic;
+
+import com.bartlomiejpluta.samplegame.core.ui.Window;
+
+public interface GameLogic {
+   void init(Window window);
+
+   void input(Window window);
+
+   void update(float dt);
+
+   void render(Window window);
+
+   void cleanUp();
+}

app/src/main/java/com/bartlomiejpluta/samplegame/core/thread/ThreadManager.java

@@ -4,7 +4,7 @@ import org.springframework.stereotype.Component;
 
 @Component
 public class ThreadManager {
-   public Thread createThread(Runnable runnable) {
-      return new Thread(runnable);
+   public Thread createThread(String name, Runnable runnable) {
+      return new Thread(runnable, name);
    }
 }

app/src/main/java/com/bartlomiejpluta/samplegame/core/ui/Window.java

@@ -3,6 +3,8 @@ package com.bartlomiejpluta.samplegame.core.ui;
 import com.bartlomiejpluta.samplegame.core.error.AppException;
 import lombok.AccessLevel;
 import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.Setter;
 import org.lwjgl.glfw.GLFWErrorCallback;
 import org.lwjgl.glfw.GLFWVidMode;
 import org.lwjgl.opengl.GL;
@@ -15,9 +17,16 @@ import static org.lwjgl.system.MemoryUtil.NULL;
 @AllArgsConstructor(access = AccessLevel.PRIVATE)
 public class Window {
    private final String title;
-   private int width;
-   private int height;
    private long windowHandle;
+
+   @Getter
+   private int width;
+
+   @Getter
+   private int height;
+
+   @Getter
+   @Setter
    private boolean resized;
 
    public void init() {
@@ -102,6 +111,6 @@ public class Window {
    }
 
    public static Window create(String title, int width, int height) {
-      return new Window(title, width, height, -1, false);
+      return new Window(title, -1, width, height, false);
    }
 }

app/src/main/java/com/bartlomiejpluta/samplegame/core/util/res/ResourcesManager.java

@@ -0,0 +1,19 @@
+package com.bartlomiejpluta.samplegame.core.util.res;
+
+import com.bartlomiejpluta.samplegame.core.error.AppException;
+import org.springframework.stereotype.Component;
+
+import java.io.InputStream;
+import java.util.Scanner;
+
+@Component
+public class ResourcesManager {
+   public String loadResourceAsString(String fileName) {
+      try (InputStream in = ResourcesManager.class.getResourceAsStream(fileName);
+           Scanner scanner = new Scanner(in, java.nio.charset.StandardCharsets.UTF_8.name())) {
+         return scanner.useDelimiter("\\A").next();
+      } catch (Exception e) {
+         throw new AppException(e);
+      }
+   }
+}

app/src/main/java/com/bartlomiejpluta/samplegame/game/logic/DefaultGameLogic.java

@@ -0,0 +1,42 @@
+package com.bartlomiejpluta.samplegame.game.logic;
+
+import com.bartlomiejpluta.samplegame.core.gl.render.Renderer;
+import com.bartlomiejpluta.samplegame.core.logic.GameLogic;
+import com.bartlomiejpluta.samplegame.core.ui.Window;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor(onConstructor = @__(@Autowired))
+public class DefaultGameLogic implements GameLogic {
+   private final Renderer renderer;
+
+   @Override
+   public void init(Window window) {
+      log.info("Initializing game logic");
+      renderer.init();
+   }
+
+   @Override
+   public void input(Window window) {
+
+   }
+
+   @Override
+   public void update(float dt) {
+
+   }
+
+   @Override
+   public void render(Window window) {
+      renderer.render(window);
+   }
+
+   @Override
+   public void cleanUp() {
+      renderer.cleanUp();
+   }
+}

app/src/main/resources/shaders/default.fs

@@ -0,0 +1,8 @@
+#version 330
+
+out vec4 fragColor;
+
+void main()
+{
+   fragColor = vec4(0.0, 0.5, 0.5, 1.0);
+}

app/src/main/resources/shaders/default.vs

@@ -0,0 +1,8 @@
+#version 330
+
+layout(location=0) in vec3 position;
+
+void main()
+{
+   gl_Position = vec4(position, 1.0);
+}