Matrices.java

package base;

import static org.lwjgl.opengl.GL20.glUniformMatrix4;
import static org.lwjgl.opengl.GL20.glUseProgram;

import java.nio.FloatBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.util.vector.Matrix4f;
import org.lwjgl.util.vector.Vector3f;

public class Matrices {
    public static Matrix4f perspectiveMatrix, viewMatrix, modelMatrix;
    public static int perspectiveMatrixLocation, viewMatrixLocation, modelMatrixLocation;
    public static void setupPerspective(float fieldOfView, float WIDTH, float HEIGHT, float zNear, float zFar){
        perspectiveMatrix = new Matrix4f();
        perspectiveMatrix.setIdentity();

        float aspectRatio = WIDTH / HEIGHT;
        float zRange = zNear - zFar;

        perspectiveMatrix.m00 = (float) (1.0f / (aspectRatio * Math.tan(degreesToRadians(fieldOfView / 2.0f))));
        perspectiveMatrix.m11 =  (float) (1.0f / (Math.tan(degreesToRadians(fieldOfView / 2.0f))));
        perspectiveMatrix.m22 = (-zNear - zFar) / zRange;
        perspectiveMatrix.m23 = 1;
        perspectiveMatrix.m32 = (2 * zFar * zNear) / zRange;
    }

    public static void setupModel(){
        modelMatrix = new Matrix4f();
        modelMatrix.setIdentity();
    }

    public static void uploadMatrices(int shaderProgramId, int perspectiveMatrixLocation, int viewMatrixLocation, int modelMatrixLocation){
        FloatBuffer matrix44Buffer = BufferUtils.createFloatBuffer(16);
        glUseProgram(shaderProgramId);
            perspectiveMatrix.store(matrix44Buffer);
            matrix44Buffer.flip();
            glUniformMatrix4(perspectiveMatrixLocation, false, matrix44Buffer);

            viewMatrix.store(matrix44Buffer);
            matrix44Buffer.flip();
            glUniformMatrix4(viewMatrixLocation, false, matrix44Buffer);

            modelMatrix.store(matrix44Buffer);
            matrix44Buffer.flip();
            glUniformMatrix4(modelMatrixLocation, false, matrix44Buffer);
        glUseProgram(0);
    }

    public static float degreesToRadians(float angle){
        return angle * (float)(Math.PI / 180d);
    }
}