uk.co.ifs_studios.engine.geometry.BasicDrawElement.java Source code

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Here is the source code for uk.co.ifs_studios.engine.geometry.BasicDrawElement.java

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/*
Copyright (C) 2013 IFS Studios
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package uk.co.ifs_studios.engine.geometry;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL15;
import org.lwjgl.opengl.GL20;
import org.lwjgl.opengl.GL30;
import org.lwjgl.util.vector.Matrix4f;

import uk.co.ifs_studios.engine.Engine;
import uk.co.ifs_studios.engine.geometry.util.Color;
import uk.co.ifs_studios.engine.geometry.util.Vertex;
import uk.co.ifs_studios.engine.shader.shaders.BasicShader;

/**
 * A class that represents an OpenGL Draw Element using the in-built
 * BasicShader.
 * 
 * @author BleedObsidian (Jesse Prescott)
 */
public class BasicDrawElement implements DrawElement {
    private final BasicShader shader;

    private Matrix4f modelMatrix;
    private final FloatBuffer matrixBuffer;

    private int vao;
    private int vbo;
    private int ibo;
    private int cbo;

    private int indiceCount;

    /**
     * Create new DrawElement.
     */
    public BasicDrawElement() {
        this.shader = new BasicShader();

        this.matrixBuffer = BufferUtils.createFloatBuffer(16);

        this.vao = GL30.glGenVertexArrays();
        this.vbo = GL15.glGenBuffers();
        this.ibo = GL15.glGenBuffers();
        this.cbo = GL15.glGenBuffers();
    }

    /**
     * Set verticies to DrawElement.
     * 
     * @param verticies
     *            - Verticies.
     */
    public void setVerticies(Vertex[] verticies) {
        float[] vertexValues = new float[verticies.length * 4];

        int vertexIndex = 0;
        for (int i = 0; i < vertexValues.length; i += 4) {
            vertexValues[i + 0] = verticies[vertexIndex].getX();
            vertexValues[i + 1] = verticies[vertexIndex].getY();
            vertexValues[i + 2] = verticies[vertexIndex].getZ();
            vertexValues[i + 3] = verticies[vertexIndex].getW();

            vertexIndex++;
        }

        FloatBuffer verticiesBuffer = BufferUtils.createFloatBuffer(vertexValues.length);
        verticiesBuffer.put(vertexValues);
        verticiesBuffer.flip();

        GL30.glBindVertexArray(this.vao);

        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.vbo);
        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, verticiesBuffer, GL15.GL_STATIC_DRAW);
        GL20.glVertexAttribPointer(0, 4, GL11.GL_FLOAT, false, 0, 0);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

        GL30.glBindVertexArray(0);
    }

    /**
     * Set colors to DrawElement.
     * 
     * @param colors
     *            - Colors.
     */
    public void setColors(Color[] colors) {
        float[] colorValues = new float[colors.length * 4];

        int colorIndex = 0;
        for (int i = 0; i < colorValues.length; i += 4) {
            colorValues[i + 0] = colors[colorIndex].getRed();
            colorValues[i + 1] = colors[colorIndex].getGreen();
            colorValues[i + 2] = colors[colorIndex].getBlue();
            colorValues[i + 3] = colors[colorIndex].getAlpha();

            colorIndex++;
        }

        FloatBuffer colorsBuffer = BufferUtils.createFloatBuffer(colorValues.length);
        colorsBuffer.put(colorValues);
        colorsBuffer.flip();

        GL30.glBindVertexArray(this.vao);

        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.cbo);
        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, colorsBuffer, GL15.GL_STREAM_DRAW);
        GL20.glVertexAttribPointer(1, 4, GL11.GL_FLOAT, false, 0, 0);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

        GL30.glBindVertexArray(0);
    }

    /**
     * Set indices to DrawElement.
     * 
     * @param indices
     *            - Indices.
     */
    public void setIndices(byte[] indices) {
        this.indiceCount = indices.length;

        ByteBuffer indiciesBuffer = BufferUtils.createByteBuffer(this.indiceCount);
        indiciesBuffer.put(indices);
        indiciesBuffer.flip();

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.ibo);

        GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, indiciesBuffer, GL15.GL_STATIC_DRAW);

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
    }

    /**
     * Set model matrix.
     */
    public void setModelMatrix(Matrix4f matrix) {
        this.modelMatrix = matrix;
    }

    /**
     * Render DrawElement.
     */
    public void render() {
        this.shader.getShaderProgram().use();

        Engine.getInstance().getWindow().getProjectionMatrix().store(this.matrixBuffer);
        this.matrixBuffer.flip();
        GL20.glUniformMatrix4(this.shader.getProjectionMatrixLocation(), false, this.matrixBuffer);

        Engine.getInstance().getGame().getCurrentState().getCamera().getViewMatrix().store(this.matrixBuffer);
        this.matrixBuffer.flip();
        GL20.glUniformMatrix4(this.shader.getViewMatrixLocation(), false, this.matrixBuffer);

        this.modelMatrix.store(this.matrixBuffer);
        this.matrixBuffer.flip();
        GL20.glUniformMatrix4(this.shader.getModelMatrixLocation(), false, this.matrixBuffer);

        GL30.glBindVertexArray(this.vao);
        GL20.glEnableVertexAttribArray(0);
        GL20.glEnableVertexAttribArray(1);

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.ibo);

        GL11.glDrawElements(GL11.GL_TRIANGLES, this.indiceCount, GL11.GL_UNSIGNED_BYTE, 0);

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);

        GL20.glDisableVertexAttribArray(0);
        GL30.glBindVertexArray(0);

        this.shader.getShaderProgram().unuse();
    }
}