OpenGLGeometry.java :  » App » skylight1 » skylight1 » opengl » Android Open Source

package skylight1.opengl;

import java.nio.IntBuffer;

import javax.microedition.khronos.opengles.GL10;

/**
 * A Geometry that can render itself to an OpenGL context.
 */
public class OpenGLGeometry {
  private final int mode;

  private final int first;

  final int numberOfVerticies;

  private OpenGLGeometryBuilderImpl<?, ?> openGLGeometryBuilderImpl;
  
  private final Texture texture;

  private final int modelPositionInBuffer;

  private final int texturePositionInBuffer;

  private final int normalsPositionInBuffer;

  private final int coloursPositionInBuffer;
  
  private final float[] boundingSphere;

  public OpenGLGeometry(final int aMode, final int aFirst, final int aNumberOfVerticies,
      final OpenGLGeometryBuilderImpl<?, ?> anOpenGLGeometryBuilderImpl, final float[] aBoundingSphere,
      final Texture aTexture) {
    mode = aMode;
    first = aFirst;
    numberOfVerticies = aNumberOfVerticies;
    openGLGeometryBuilderImpl = anOpenGLGeometryBuilderImpl;
    boundingSphere = aBoundingSphere;
    texture = aTexture;
    
    // To reduce calculations in the draw method, pre-calculate some offets
    modelPositionInBuffer = first * FastGeometryBuilderImpl.MODEL_COORDINATES_PER_VERTEX;
    texturePositionInBuffer = first * FastGeometryBuilderImpl.TEXTURE_COORDINATES_PER_VERTEX;
    normalsPositionInBuffer = first * FastGeometryBuilderImpl.NORMAL_COMPONENTS_PER_VERTEX;
    coloursPositionInBuffer = first * FastGeometryBuilderImpl.COLOUR_PARTS_PER_VERTEX;
  }

  /**
   * Draws the geometry defined by this object. If the geometry builder is not active, and any associated texture,
   * then the results are unpredictable.
   */
  public void draw(GL10 aGL10) {
    texture.activate();
    aGL10.glDrawArrays(mode, first, numberOfVerticies);
  }

  public float[] getBoundingSphere() {
    return boundingSphere;
  }

  /**
   * Updates the model associated with this geometry.
   */
  public void updateModel(FastGeometryBuilder<?, ?> aFastGeometryBuilder) {
    if (!openGLGeometryBuilderImpl.complete) {
      throw new IllegalStateException(
          "Updates are not permitted until after the first time the geometry builder has been enabled.");
    }
    final IntBuffer modelCoordinatesAsBuffer = openGLGeometryBuilderImpl.modelCoordinatesAsBuffer;
    modelCoordinatesAsBuffer.position(modelPositionInBuffer);
    modelCoordinatesAsBuffer.put(((FastGeometryBuilderImpl<?, ?>) aFastGeometryBuilder).modelCoordinates);
  }

  /**
   * Updates the textures associated with this geometry.
   */
  public void updateTexture(FastGeometryBuilder<?, ?> aFastGeometryBuilder) {
    if (!openGLGeometryBuilderImpl.complete) {
      throw new IllegalStateException(
          "Updates are not permitted until after the first time the geometry builder has been enabled.");
    }
    final IntBuffer textureCoordinatesAsBuffer = openGLGeometryBuilderImpl.textureCoordinatesAsBuffer;
    textureCoordinatesAsBuffer.position(texturePositionInBuffer);
    textureCoordinatesAsBuffer.put(((FastGeometryBuilderImpl<?, ?>) aFastGeometryBuilder).textureCoordinates);
    textureCoordinatesAsBuffer.position(0);
  }

  /**
   * Updates the normals associated with this geometry.
   */
  public void updateNormals(FastGeometryBuilder<?, ?> aFastGeometryBuilder) {
    if (!openGLGeometryBuilderImpl.complete) {
      throw new IllegalStateException(
          "Updates are not permitted until after the first time the geometry builder has been enabled.");
    }
    final IntBuffer normalAsBuffer = openGLGeometryBuilderImpl.normalsAsBuffer;
    normalAsBuffer.position(normalsPositionInBuffer);
    normalAsBuffer.put(((FastGeometryBuilderImpl<?, ?>) aFastGeometryBuilder).normalComponents);
  }

  /**
   * Updates the colours associated with this geometry.
   */
  public void updateColours(FastGeometryBuilder<?, ?> aFastGeometryBuilder) {
    if (!openGLGeometryBuilderImpl.complete) {
      throw new IllegalStateException("Updates are not permitted until after the first time the geometry builder has been enabled.");
    }
    final IntBuffer coloursAsBuffer = openGLGeometryBuilderImpl.coloursAsBuffer;
    coloursAsBuffer.position(coloursPositionInBuffer);
    coloursAsBuffer.put(((FastGeometryBuilderImpl<?, ?>) aFastGeometryBuilder).colours);
  }
}