se.angergard.engine.graphics.Mesh.java Source code

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Here is the source code for se.angergard.engine.graphics.Mesh.java

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/********************************************************************************
 *
 *   Copyright 2014 Theodor Angergard
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 *******************************************************************************/

package se.angergard.engine.graphics;

import java.nio.*;
import java.util.*;

import org.lwjgl.opengl.*;

import se.angergard.engine.util.Util;

public abstract class Mesh {

    public Mesh(long vertexBufferSize, long indicesBufferSize, int usage) {
        if (aMeshCreated) {
            new Exception("You can't create multiple meshes as of right now. This is due to a bug")
                    .printStackTrace();
        }

        vbo = GL15.glGenBuffers();
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, vertexBufferSize, usage);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

        ibo = GL15.glGenBuffers();
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, ibo);
        GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBufferSize, usage);
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);

        this.VERTEX_BUFFER_SIZE = vertexBufferSize;
        this.INDICES_BUFFER_SIZE = indicesBufferSize;

        this.INDICES_LENGTH = (int) indicesBufferSize / 4; // removes bytes

        aMeshCreated = true;
    }

    private static boolean aMeshCreated = false;

    private final int vbo, ibo;

    public final long VERTEX_BUFFER_SIZE, INDICES_BUFFER_SIZE;
    public final int INDICES_LENGTH;

    public final void setVertices(FloatBuffer buffer) {
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
        GL15.glBufferSubData(GL15.GL_ARRAY_BUFFER, 0, buffer);
        // GL15.glBufferData(GL15.GL_ARRAY_BUFFER, buffer, GL15.GL_DYNAMIC_DRAW);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
    }

    public final void setIndices(IntBuffer buffer) {
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, ibo);
        GL15.glBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, 0, buffer);
        // GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, buffer, GL15.GL_DYNAMIC_DRAW);
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
    }

    public final void setIndices(ArrayList<Integer> indices) {
        setIndices(Util.toFlippedIntBuffer(indices));
    }

    public final void setIndices(int[] indices) {
        setIndices(Util.toFlippedIntBuffer(indices));
    }

    public void draw() {
        GL20.glEnableVertexAttribArray(0);
        GL20.glEnableVertexAttribArray(1);

        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, ibo);

        GL20.glVertexAttribPointer(0, 2, GL11.GL_FLOAT, false, Vertex2D.SIZE_BYTES, 0);
        GL20.glVertexAttribPointer(1, 2, GL11.GL_FLOAT, false, Vertex2D.SIZE_BYTES, 8);
        GL11.glDrawElements(GL11.GL_TRIANGLES, INDICES_LENGTH, GL11.GL_UNSIGNED_INT, 0);

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

        GL20.glDisableVertexAttribArray(0);
        GL20.glDisableVertexAttribArray(1);
    }

}