/**
* Called back immediately after the OpenGL context is initialized. Can be used to perform
* one-time initialization. Run only once.
*/
@Override
public void init(GLAutoDrawable drawable) {
GL2 gl = drawable.getGL().getGL2(); // get the OpenGL graphics context
glu = new GLU(); // get GL Utilities
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); // set background (clear) color
gl.glClearDepth(1.0f); // set clear depth value to farthest
// Do not enable depth test
// gl.glEnable(GL_DEPTH_TEST); // enables depth testing
// gl.glDepthFunc(GL_LEQUAL); // the type of depth test to do
gl.glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // best perspective correction
gl.glShadeModel(GL_SMOOTH); // blends colors nicely, and smoothes out lighting
// Load the texture image
try {
// Use URL so that can read from JAR and disk file.
BufferedImage image = ImageIO.read(this.getClass().getResource(textureFileName));
// Create a OpenGL Texture object
texture = AWTTextureIO.newTexture(GLProfile.getDefault(), image, false);
// Use linear filter if image is larger than the original texture
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// Use linear filter if image is smaller than the original texture
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
} catch (GLException | IOException e) {
e.printStackTrace();
}
// Texture image flips vertically. Shall use TextureCoords class to retrieve
// the top, bottom, left and right coordinates, instead of using 0.0f and 1.0f.
TextureCoords textureCoords = texture.getImageTexCoords();
textureCoordTop = textureCoords.top();
textureCoordBottom = textureCoords.bottom();
textureCoordLeft = textureCoords.left();
textureCoordRight = textureCoords.right();
// Enable the texture
texture.enable(gl);
texture.bind(gl);
// gl.glEnable(GL_TEXTURE_2D);
// Enable blending
gl.glEnable(GL_BLEND);
gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE);
// Allocate the stars
for (int i = 0; i < stars.length; i++) {
stars[i] = new Star();
// Linearly distributed according to the star number
stars[i].distance = ((float) i / numStars) * 5.0f;
}
}
protected void beginDrawIcons(DrawContext dc) {
GL2 gl = dc.getGL().getGL2(); // GL initialization checks for GL2 compatibility.
this.oglStackHandler.clear();
int attributeMask =
GL2.GL_DEPTH_BUFFER_BIT // for depth test, depth mask and depth func
| GL2.GL_TRANSFORM_BIT // for modelview and perspective
| GL2.GL_VIEWPORT_BIT // for depth range
| GL2.GL_CURRENT_BIT // for current color
| GL2.GL_COLOR_BUFFER_BIT // for alpha test func and ref, and blend
| GL2.GL_DEPTH_BUFFER_BIT // for depth func
| GL2.GL_ENABLE_BIT; // for enable/disable changes
this.oglStackHandler.pushAttrib(gl, attributeMask);
// Apply the depth buffer but don't change it.
if ((!dc.isDeepPickingEnabled())) gl.glEnable(GL.GL_DEPTH_TEST);
gl.glDepthMask(false);
// Suppress any fully transparent image pixels
gl.glEnable(GL2.GL_ALPHA_TEST);
gl.glAlphaFunc(GL2.GL_GREATER, 0.001f);
// Load a parallel projection with dimensions (viewportWidth, viewportHeight)
this.oglStackHandler.pushProjectionIdentity(gl);
gl.glOrtho(
0d, dc.getView().getViewport().width, 0d, dc.getView().getViewport().height, -1d, 1d);
this.oglStackHandler.pushModelview(gl);
this.oglStackHandler.pushTexture(gl);
if (dc.isPickingMode()) {
this.pickSupport.beginPicking(dc);
// Set up to replace the non-transparent texture colors with the single pick color.
gl.glEnable(GL.GL_TEXTURE_2D);
gl.glTexEnvf(GL2.GL_TEXTURE_ENV, GL2.GL_TEXTURE_ENV_MODE, GL2.GL_COMBINE);
gl.glTexEnvf(GL2.GL_TEXTURE_ENV, GL2.GL_SRC0_RGB, GL2.GL_PREVIOUS);
gl.glTexEnvf(GL2.GL_TEXTURE_ENV, GL2.GL_COMBINE_RGB, GL2.GL_REPLACE);
} else {
gl.glEnable(GL.GL_TEXTURE_2D);
gl.glEnable(GL.GL_BLEND);
gl.glBlendFunc(GL.GL_ONE, GL.GL_ONE_MINUS_SRC_ALPHA);
}
}
