Attempt adding GLSL shaders for basic color. Not working atm.

README.md

@@ -1,6 +1,6 @@
 # Warabi
 
-This is a game engine, that doesn't make games.... or engines.
+This is a game engine, that doesn't make games.....
 
 <sub>......and its written in Java, sorry.</sub>
 

src/main/java/com/okseby/core/ObjectLoader.java

@@ -8,6 +8,7 @@ import org.lwjgl.opengl.GL20;
 import org.lwjgl.opengl.GL30;
 
 import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -15,8 +16,9 @@ public class ObjectLoader {
     private List<Integer> vaos = new ArrayList<>();
     private List<Integer> vbos = new ArrayList<>();
 
-    public Model loadModel(float[] vertices) {
+    public Model loadModel(float[] vertices, int[] indices) {
         int id = createVAO();
+        storeIndicesBuffer(indices);
         storeDataInAttributeList(0, 3, vertices);
         unbind();
 
@@ -31,6 +33,14 @@ public class ObjectLoader {
         return id;
     }
 
+    private void storeIndicesBuffer(int[] indices) {
+        int vbo = GL15.glGenBuffers();
+        vbos.add(vbo);
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, vbo);
+        IntBuffer buffer = Utils.storeDataInIntBuffer(indices);
+        GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, buffer, GL15.GL_STATIC_DRAW);
+    }
+
     private void storeDataInAttributeList(int attributeNumber, int vertexCount, float[] data) {
         int vbo = GL15.glGenBuffers();
         vbos.add(vbo);

src/main/java/com/okseby/core/RenderManager.java

@@ -1,20 +1,40 @@
 package com.okseby.core;
 
+import com.okseby.core.entity.Model;
+import com.okseby.core.utils.Utils;
 import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL20;
+import org.lwjgl.opengl.GL30;
 
 public class RenderManager {
     private final WindowManager window;
+    private ShaderManager shader;
 
     public RenderManager() {
         window = Launcher.getWindow();
     }
 
     public void init() throws Exception {
+        shader = new ShaderManager();
 
+        shader.createVertexShader(Utils.loadResource("/shaders/vertex.vs"));
+        shader.createFragmentShader(Utils.loadResource("/shaders/fragment.fs"));
+
+        shader.link();
     }
 
-    public void render() {
+    public void render(Model model) {
+        clear();
 
+        shader.bind();
+
+        GL30.glBindVertexArray(model.getId());
+        GL20.glEnableVertexAttribArray(0);
+        GL11.glDrawArrays(GL11.GL_TRIANGLES, 0, model.getVertexCount());
+        GL20.glDisableVertexAttribArray(0);
+        GL30.glBindVertexArray(0);
+
+        shader.unbind();
     }
 
     public void clear() {
@@ -22,6 +42,6 @@ public class RenderManager {
     }
 
     public void cleanup() {
-
+        shader.cleanup();
     }
 }

src/main/java/com/okseby/core/ShaderManager.java

@@ -0,0 +1,68 @@
+package com.okseby.core;
+
+import org.lwjgl.opengl.GL20;
+
+public class ShaderManager {
+    private final int programID;
+    private int vertexShaderID, fragmentShaderID;
+
+    public ShaderManager() throws Exception {
+        programID = GL20.glCreateProgram();
+        if (programID == 0)
+            throw new Exception("Could not create shader");
+    }
+
+    public void createVertexShader(String shaderCode) throws Exception {
+        vertexShaderID = createShader(shaderCode, GL20.GL_VERTEX_SHADER);
+    }
+
+    public void createFragmentShader(String shaderCode) throws Exception {
+        fragmentShaderID = createShader(shaderCode, GL20.GL_FRAGMENT_SHADER);
+    }
+
+    public int createShader(String shaderCode, int shaderType) throws Exception {
+        int shaderID = GL20.glCreateShader(shaderType);
+        if (shaderID == 0)
+            throw new Exception("Error creating shader. Type: " + shaderType);
+
+        GL20.glShaderSource(shaderID, shaderCode);
+        GL20.glCompileShader(shaderID);
+
+        if (GL20.glGetShaderi(shaderID, GL20.GL_COMPILE_STATUS) == 0)
+            throw new Exception("Error compiling shader code. Type: " + shaderType + " Info: " + GL20.glGetShaderInfoLog(shaderID, 1024));
+
+        GL20.glAttachShader(programID, shaderID);
+
+        return shaderID;
+    }
+
+    public void link() throws Exception {
+        GL20.glLinkProgram(programID);
+        if (GL20.glGetProgrami(programID, GL20.GL_LINK_STATUS) == 0)
+            throw new Exception("Error linking shader code. Info: " + GL20.glGetProgramInfoLog(programID, 1024));
+
+        if (vertexShaderID != 0)
+            GL20.glDetachShader(programID, vertexShaderID);
+
+        if (fragmentShaderID != 0)
+            GL20.glDetachShader(programID, fragmentShaderID);
+
+        GL20.glValidateProgram(programID);
+        if (GL20.glGetProgrami(programID, GL20.GL_VALIDATE_STATUS) == 0)
+            throw new Exception("Unable to validate shader code: " + GL20.glGetProgramInfoLog(programID, 1024));
+    }
+
+    public void bind() {
+        GL20.glUseProgram(programID);
+    }
+
+    public void unbind() {
+        GL20.glUseProgram(0);
+    }
+
+    public void cleanup() {
+        unbind();
+        if (programID != 0)
+            GL20.glDeleteProgram(programID);
+    }
+}

src/main/java/com/okseby/core/test/TestGame.java

@@ -34,7 +34,12 @@ public class TestGame implements ILogic {
                 -0.5f, 0.5f, 0f
         };
 
-        model = loader.loadModel(vertices);
+        int[] indices = {
+                0, 1, 3,
+                3, 1, 2
+        };
+
+        model = loader.loadModel(vertices, indices);
     }
 
     @Override

src/main/java/com/okseby/core/utils/Utils.java

@@ -2,7 +2,11 @@ package com.okseby.core.utils;
 
 import org.lwjgl.system.MemoryUtil;
 
+import java.io.InputStream;
 import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Scanner;
 
 public class Utils {
     public static FloatBuffer storeDataInFloatBuffer(float[] data) {
@@ -11,4 +15,20 @@ public class Utils {
 
         return buffer;
     }
+
+    public static IntBuffer storeDataInIntBuffer(int[] data) {
+        IntBuffer buffer = MemoryUtil.memAllocInt(data.length);
+        buffer.put(data).flip();
+
+        return buffer;
+    }
+
+    public static String loadResource(String filename) throws Exception {
+        String result;
+        try (InputStream in = Utils.class.getResourceAsStream(filename);
+             Scanner scanner = new Scanner(in, StandardCharsets.UTF_8.name())) {
+            result = scanner.useDelimiter("\\A").next();
+        }
+        return result;
+    }
 }

src/main/resources/shaders/fragment.fs

@@ -0,0 +1,9 @@
+#version 400 core
+
+in vec3 color;
+
+out vec4 fragmentColor;
+
+void main() {
+    fragmentColor = vec4(color, 1.0);
+}

src/main/resources/shaders/vertex.vs

@@ -0,0 +1,10 @@
+#version 400 core
+
+in vec3 position;
+
+out vec3 color;
+
+void main() {
+    gl_Position = vec4(position, 1.0);
+    color = vec3(position.x + 0.25, 0.17, position.y + 0.25);
+}