GLG2DUtils.java

/*
 * Copyright 2015 Brandon Borkholder
 *
 * 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 org.jogamp.glg2d;

import java.awt.Color;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.jogamp.opengl.GL;
import com.jogamp.opengl.GL2ES1;

public class GLG2DUtils {
  private static final Logger LOGGER = Logger.getLogger(GLG2DUtils.class.getName());

  public static void setColor(GL2ES1 gl, Color c, float preMultiplyAlpha) {
    int rgb = c.getRGB();
    gl.glColor4ub((byte) (rgb >> 16 & 0xFF), (byte) (rgb >> 8 & 0xFF), (byte) (rgb & 0xFF), (byte) ((rgb >> 24 & 0xFF) * preMultiplyAlpha));
  }

  public static float[] getGLColor(Color c) {
    return c.getComponents(null);
  }

  public static int getViewportHeight(GL gl) {
    int[] viewportDimensions = new int[4];
    gl.glGetIntegerv(GL.GL_VIEWPORT, viewportDimensions, 0);
    int canvasHeight = viewportDimensions[3];
    return canvasHeight;
  }

  public static void logGLError(GL gl) {
    int error = gl.glGetError();
    if (error != GL.GL_NO_ERROR) {
      LOGGER.log(Level.SEVERE, "GL Error: code " + error);
    }
  }

  public static int ensureIsGLBuffer(GL gl, int bufferId) {
    if (gl.glIsBuffer(bufferId)) {
      return bufferId;
    } else {
      return genBufferId(gl);
    }
  }

  public static int genBufferId(GL gl) {
    int[] ids = new int[1];
    gl.glGenBuffers(1, ids, 0);
    return ids[0];
  }
}