From 5d2acb70c7e0513ad9fcaf2c7d59cb4094201830 Mon Sep 17 00:00:00 2001
From: Edouard DUPIN <yui.heero@gmail.com>
Date: Sat, 18 Apr 2020 22:53:42 +0200
Subject: [PATCH] [DEV] tutorial 7 'uniform' implementation

---
 src/module-info.java           |  1 +
 src/shaders/ShaderProgram.java | 35 +++++++++++++++++++++++++++++++++-
 src/shaders/StaticShader.java  | 12 ++++++++++++
 src/shaders/vertexShader.txt   |  4 +++-
 src/toolbox/Maths.java         | 18 +++++++++++++++++
 5 files changed, 68 insertions(+), 2 deletions(-)
 create mode 100644 src/toolbox/Maths.java

diff --git a/src/module-info.java b/src/module-info.java
index 613a246..879c9ef 100644
--- a/src/module-info.java
+++ b/src/module-info.java
@@ -17,6 +17,7 @@ open module Tutorial {
 	requires transitive org.lwjgl.stb.natives;
 	requires transitive org.lwjgl.opengl;
 	requires transitive org.lwjgl.opengl.natives;
+	
 	requires org.lwjgl.openvr;
 	requires java.desktop;
 	requires pngdecoder;
diff --git a/src/shaders/ShaderProgram.java b/src/shaders/ShaderProgram.java
index b50aeb1..4f8b783 100644
--- a/src/shaders/ShaderProgram.java
+++ b/src/shaders/ShaderProgram.java
@@ -3,7 +3,12 @@ package shaders;
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
+import java.nio.FloatBuffer;
 
+import javax.vecmath.Matrix4f;
+import javax.vecmath.Vector3f;
+
+import org.lwjgl.BufferUtils;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL20;
 
@@ -12,6 +17,7 @@ public abstract class ShaderProgram {
 	private int programID;
 	private int vertexShaderID;
 	private int fragmentShaderID;
+	
 
 	public ShaderProgram (String vertexFile, String fragmentFile) {
 		vertexShaderID = loadShader(vertexFile, GL20.GL_VERTEX_SHADER);
@@ -19,11 +25,17 @@ public abstract class ShaderProgram {
 		programID = GL20.glCreateProgram();
 		GL20.glAttachShader(programID, vertexShaderID);
 		GL20.glAttachShader(programID, fragmentShaderID);
+		bindAttributes();
 		GL20.glLinkProgram(programID);
 		GL20.glValidateProgram(programID);
-		bindAttributes();
+		getAllUniformLocations();
 	}
+	protected abstract void getAllUniformLocations();
 
+	protected int getUniformLocation(String uniformName) {
+		return GL20.glGetUniformLocation(programID, uniformName);
+	}
+	
 	public void start() {
 		GL20.glUseProgram(programID);
 	}
@@ -44,6 +56,27 @@ public abstract class ShaderProgram {
 	protected void bindAttribute(int attribute, String variableName) {
 		GL20.glBindAttribLocation(programID, attribute, variableName);
 	}
+
+	protected void loadFloat(int location, float value) {
+		GL20.glUniform1f(location, value);
+	}
+
+	protected void loadVector(int location, Vector3f value) {
+		GL20.glUniform3f(location, value.x, value.y, value.z);
+	}
+	protected void loadBoolean(int location, boolean value) {
+		GL20.glUniform1f(location, value?1.0f:0.0f);
+	}
+
+	protected void loadMatrix(int location, Matrix4f value) {
+		float[] values = new float[] {
+				value.m00, value.m01, value.m02, value.m03,
+				value.m10, value.m11, value.m12, value.m13,
+				value.m20, value.m21, value.m22, value.m23,
+				value.m30, value.m31, value.m32, value.m33
+		};
+		GL20.glUniformMatrix4fv(location, false, values);
+	}
 	
 	private static int loadShader(String file, int type) {
 		StringBuilder shaderSource = new StringBuilder();
diff --git a/src/shaders/StaticShader.java b/src/shaders/StaticShader.java
index ae6d9f9..30d7c3b 100644
--- a/src/shaders/StaticShader.java
+++ b/src/shaders/StaticShader.java
@@ -1,8 +1,12 @@
 package shaders;
 
+import javax.vecmath.Matrix4f;
+
 public class StaticShader extends ShaderProgram {
 	private static final String VERTEX_FILE = "src/shaders/vertexShader.txt";
 	private static final String FRAGMENT_FILE = "src/shaders/fragmentShader.txt";
+
+	private int location_transformationMatrix;
 	
 	public StaticShader() {
 		super(VERTEX_FILE, FRAGMENT_FILE);
@@ -13,5 +17,13 @@ public class StaticShader extends ShaderProgram {
 		super.bindAttribute(0, "position");
 		super.bindAttribute(1, "textureCoords");
 	}
+
+	@Override
+	protected void getAllUniformLocations() {
+		location_transformationMatrix = super.getUniformLocation("transformationMatrix");
+	}
 	
+	public void loadTransformationMatrix(Matrix4f value) {
+		super.loadMatrix(location_transformationMatrix, value);
+	}
 }
diff --git a/src/shaders/vertexShader.txt b/src/shaders/vertexShader.txt
index ee4b5e1..43600fc 100644
--- a/src/shaders/vertexShader.txt
+++ b/src/shaders/vertexShader.txt
@@ -5,9 +5,11 @@ in vec2 textureCoords;
 
 out vec2 pass_textureCoords;
 
+uniform mat4 transformationMatrix;
+
 void main(void) {
 
-	gl_Position = vec4(position, 1.0);
+	gl_Position = transformationMatrix * vec4(position, 1.0);
 	pass_textureCoords = textureCoords;
 }
 
diff --git a/src/toolbox/Maths.java b/src/toolbox/Maths.java
new file mode 100644
index 0000000..351f6a1
--- /dev/null
+++ b/src/toolbox/Maths.java
@@ -0,0 +1,18 @@
+package toolbox;
+
+import javax.vecmath.Matrix4f;
+import javax.vecmath.Vector3f;
+
+public class Maths {
+
+	public static Matrix4f createTransformationMatrix(Vector3f translation, Vector3f rotation, float scale) {
+		Matrix4f matrix = new Matrix4f();
+		matrix.setIdentity();
+		matrix.setTranslation(translation);
+		matrix.rotX(rotation.x);
+		matrix.rotY(rotation.y);
+		matrix.rotZ(rotation.z);
+		matrix.setScale(scale);
+		return matrix;
+	}
+}