zildo.fwk.opengl.Utils.java Source code

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Here is the source code for zildo.fwk.opengl.Utils.java

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/**
 * Legend of Zildo
 * Copyright (C) 2006-2011 Evariste Boussaton
 * Based on original Zelda : link to the past (C) Nintendo 1992
 *
 * 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 zildo.fwk.opengl;

import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.ARBVertexBufferObject;
import org.lwjgl.opengl.GL11;

/**
 * @author eboussaton
 */
public class Utils {

    public static int generateTexture(int sizeX, int sizeY) {
        IntBuffer buf = ByteBuffer.allocateDirect(4).order(ByteOrder.nativeOrder()).asIntBuffer();
        GL11.glGenTextures(buf); // Create Texture In OpenGL
        int textureID = buf.get(0);
        GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID);
        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);

        GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, adjustTexSize(sizeX), adjustTexSize(sizeY), 0,
                GL11.GL_RGBA, GL11.GL_UNSIGNED_BYTE, (ByteBuffer) null);

        return textureID;
    }

    public static void cleanTexture(int id) {
        GL11.glDeleteTextures(getBufferWithId(id));
    }

    public static int createVBO() {
        IntBuffer buffer = BufferUtils.createIntBuffer(1);
        ARBVertexBufferObject.glGenBuffersARB(buffer);
        return buffer.get();
    }

    // Vertex & Indices Buffer
    public static void bufferData(int id, Buffer buffer) {
        ARBVertexBufferObject.glBindBufferARB(ARBVertexBufferObject.GL_ARRAY_BUFFER_ARB, id);
        if (buffer instanceof FloatBuffer) {
            ARBVertexBufferObject.glBufferDataARB(ARBVertexBufferObject.GL_ARRAY_BUFFER_ARB, (FloatBuffer) buffer,
                    ARBVertexBufferObject.GL_STREAM_DRAW_ARB);
        } else if (buffer instanceof IntBuffer) {
            ARBVertexBufferObject.glBufferDataARB(ARBVertexBufferObject.GL_ARRAY_BUFFER_ARB, (IntBuffer) buffer,
                    ARBVertexBufferObject.GL_STREAM_DRAW_ARB);
        }
    }

    /**
     * OpenGL likes "adjusted" size for texture. We take multiple of 256.
     * @param n Initial size
     * @return Adjusted size
     */
    static public int adjustTexSize(int n) {
        if (n % 256 == 0) {
            return n;
        }
        return (n & 0xff00) + 256;
    }

    public static IntBuffer getBufferWithId(int id) {
        IntBuffer buf = BufferUtils.createIntBuffer(1);
        buf.put(id);
        buf.rewind();
        return buf;
    }

    public static void copyScreenToTexture(int p_texId, int p_sizeX, int p_sizeY) {
        GL11.glBindTexture(GL11.GL_TEXTURE_2D, p_texId);

        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);

        GL11.glCopyTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGBA, 0, 0, p_sizeX, p_sizeY, 0);
    }
}