Add texture loading.

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

@@ -6,7 +6,10 @@ import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL15;
 import org.lwjgl.opengl.GL20;
 import org.lwjgl.opengl.GL30;
+import org.lwjgl.stb.STBImage;
+import org.lwjgl.system.MemoryStack;
 
+import java.nio.ByteBuffer;
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
 import java.util.ArrayList;
@@ -15,14 +18,45 @@ import java.util.List;
 public class ObjectLoader {
     private List<Integer> vaos = new ArrayList<>();
     private List<Integer> vbos = new ArrayList<>();
+    private List<Integer> textures = new ArrayList<>();
 
-    public Model loadModel(float[] vertices, int[] indices) {
+    public Model loadModel(float[] vertices, float[] textureCoordinates, int[] indices) {
         int id = createVAO();
         storeIndicesBuffer(indices);
         storeDataInAttributeList(0, 3, vertices);
+        storeDataInAttributeList(1, 2, textureCoordinates);
         unbind();
 
-        return new Model(id, vertices.length / 3);
+        return new Model(id, indices.length);
+    }
+
+    public int loadTexture(String filename) throws Exception {
+        int width, height;
+        ByteBuffer buffer;
+
+        try (MemoryStack stack = MemoryStack.stackPush()) {
+            IntBuffer w = stack.mallocInt(1);
+            IntBuffer h = stack.mallocInt(1);
+            IntBuffer c = stack.mallocInt(1);
+
+            buffer = STBImage.stbi_load(filename, w, h, c, 4);
+            if (buffer == null)
+                throw new Exception("Image File " + filename + " not loaded " + STBImage.stbi_failure_reason());
+
+            width = w.get();
+            height = h.get();
+        }
+
+        int id = GL11.glGenTextures();
+
+        textures.add(id);
+        GL11.glBindTexture(GL11.GL_TEXTURE_2D, id);
+        GL11.glPixelStorei(GL11.GL_UNPACK_ALIGNMENT, 1);
+        GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, width, height, 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, buffer);
+        GL30.glGenerateMipmap(GL11.GL_TEXTURE_2D);
+        STBImage.stbi_image_free(buffer);
+
+        return id;
     }
 
     private int createVAO() {
@@ -67,5 +101,7 @@ public class ObjectLoader {
             GL30.glDeleteVertexArrays(vao);
         for (int vbo : vbos)
             GL30.glDeleteBuffers(vbo);
+        for (int texture : textures)
+            GL11.glDeleteTextures(texture);
     }
 }

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

@@ -3,6 +3,7 @@ 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.GL13;
 import org.lwjgl.opengl.GL20;
 import org.lwjgl.opengl.GL30;
 
@@ -21,18 +22,25 @@ public class RenderManager {
         shader.createFragmentShader(Utils.loadResource("/shaders/fragment.fs"));
 
         shader.link();
+        shader.createUniform("textureSampler");
     }
 
     public void render(Model model) {
         clear();
 
         shader.bind();
+        shader.setUniform("textureSampler", 0);
 
         GL30.glBindVertexArray(model.getId());
         GL20.glEnableVertexAttribArray(0);
-        GL11.glDrawArrays(GL11.GL_TRIANGLES, 0, model.getVertexCount());
+        GL20.glEnableVertexAttribArray(1);
+        GL13.glActiveTexture(GL13.GL_TEXTURE0);
+        GL11.glBindTexture(GL11.GL_TEXTURE_2D, model.getTexture().getId());
+        GL11.glDrawElements(GL11.GL_TRIANGLES, model.getVertexCount(), GL11.GL_UNSIGNED_INT, 0);
 
         GL20.glDisableVertexAttribArray(0);
+        GL20.glDisableVertexAttribArray(1);
+
         GL30.glBindVertexArray(0);
 
         shader.unbind();

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

@@ -1,15 +1,42 @@
 package com.okseby.core;
 
+import org.joml.Matrix4f;
 import org.lwjgl.opengl.GL20;
+import org.lwjgl.system.MemoryStack;
+
+import java.util.HashMap;
+import java.util.Map;
 
 public class ShaderManager {
     private final int programID;
     private int vertexShaderID, fragmentShaderID;
 
+    private final Map<String, Integer> uniforms;
+
     public ShaderManager() throws Exception {
         programID = GL20.glCreateProgram();
         if (programID == 0)
             throw new Exception("Could not create shader");
+
+        uniforms = new HashMap<>();
+    }
+
+    public void createUniform(String uniformName) throws Exception {
+        int uniformLocation = GL20.glGetUniformLocation(programID, uniformName);
+        if (uniformLocation < 0)
+            throw new Exception("Could not find uniform " + uniformName);
+
+        uniforms.put(uniformName, uniformLocation);
+    }
+
+    public void setUniform(String uniformName, Matrix4f value) {
+        try (MemoryStack stack = MemoryStack.stackPush()) {
+            GL20.glUniformMatrix4fv(uniforms.get(uniformName), false, value.get(stack.mallocFloat(16)));
+        }
+    }
+
+    public void setUniform(String uniformName, int value) {
+        GL20.glUniform1i(uniforms.get(uniformName), value);
     }
 
     public void createVertexShader(String shaderCode) throws Exception {

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

@@ -17,9 +17,10 @@ public class WindowManager {
 
     @Getter private long window;
     @Getter private int width, height;
+    @Getter private final Matrix4f projectionMatrix;
+
     @Getter @Setter private String title;
     @Getter @Setter private boolean resizeable, vsync;
-    @Getter private final Matrix4f projectionMatrix;
 
     public WindowManager(String title, int width, int height, boolean vsync) {
         this.title = title;

src/main/java/com/okseby/core/entity/Model.java

@@ -1,13 +1,28 @@
 package com.okseby.core.entity;
 
 import lombok.Getter;
+import lombok.Setter;
 
 public class Model {
     @Getter private int id;
     @Getter private int vertexCount;
 
+    @Getter @Setter private Texture texture;
+
     public Model(int id, int vertexCount) {
         this.id = id;
         this.vertexCount = vertexCount;
     }
+
+    public Model(int id, int vertexCount, Texture texture) {
+        this.id = id;
+        this.vertexCount = vertexCount;
+        this.texture = texture;
+    }
+
+    public Model(Model model, Texture texture) {
+        this.id = model.getId();
+        this.vertexCount = model.getVertexCount();
+        this.texture = texture;
+    }
 }

src/main/java/com/okseby/core/entity/Texture.java

@@ -0,0 +1,14 @@
+package com.okseby.core.entity;
+
+import lombok.Getter;
+
+public class Texture {
+
+    @Getter private final int id;
+
+    public Texture(int id) {
+        this.id = id;
+    }
+
+
+}

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

@@ -2,6 +2,7 @@ package com.okseby.core.test;
 
 import com.okseby.core.*;
 import com.okseby.core.entity.Model;
+import com.okseby.core.entity.Texture;
 import org.lwjgl.glfw.GLFW;
 import org.lwjgl.opengl.GL11;
 
@@ -29,9 +30,7 @@ public class TestGame implements ILogic {
                 -0.5f, 0.5f, 0f,
                 -0.5f, -0.5f, 0f,
                 0.5f, -0.5f, 0f,
-                0.5f, -0.5f, 0f,
                 0.5f, 0.5f, 0f,
-                -0.5f, 0.5f, 0f
         };
 
         int[] indices = {
@@ -39,7 +38,15 @@ public class TestGame implements ILogic {
                 3, 1, 2
         };
 
-        model = loader.loadModel(vertices, indices);
+        float[] textureCoordinates = {
+                0, 0,
+                0, 1,
+                1, 1,
+                1, 0
+        };
+
+        model = loader.loadModel(vertices, textureCoordinates, indices);
+        model.setTexture(new Texture(loader.loadTexture("textures/grassblock.png")));
     }
 
     @Override

src/main/resources/shaders/fragment.fs

@@ -1,9 +1,11 @@
 #version 400 core
 
-in vec3 color;
+in vec2 fragmentTextureCoordinates;
 
 out vec4 fragmentColor;
 
+uniform sampler2D textureSampler;
+
 void main() {
-    fragmentColor = vec4(color, 1.0);
+    fragmentColor = texture(textureSampler, fragmentTextureCoordinates);
 }

src/main/resources/shaders/vertex.vs

@@ -1,10 +1,11 @@
 #version 400 core
 
 in vec3 position;
+in vec2 textureCoordinates;
 
-out vec3 color;
+out vec2 fragmentTextureCoordinates;
 
 void main() {
     gl_Position = vec4(position, 1.0);
-    color = vec3(position.x + 0.25, 0.17, position.y + 0.25);
+    fragmentTextureCoordinates = textureCoordinates;
 }