private void display(GL gl, GLU glu, final JoglFrameBufferObject theFBO) {
final int w = theFBO.getPixelWidth();
final int h = theFBO.getPixelHeight();
/* bind position data */
gl.glEnableClientState(GL.GL_VERTEX_ARRAY);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, _myVBO);
gl.glVertexPointer(4, GL.GL_FLOAT, 0, 0);
/* bind point size data */
_myShaderManager.enable(_myPointSpriteShader);
final int myPointSizeAttrib =
gl.glGetAttribLocation(_myPointSpriteShader.getOpenGLID(), "vertexAttribute");
gl.glEnableVertexAttribArray(myPointSizeAttrib);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, _myIBO);
gl.glVertexAttribPointer(myPointSizeAttrib, 3, GL.GL_FLOAT, false, 0, 0);
gl.glEnable(GL.GL_VERTEX_PROGRAM_POINT_SIZE_ARB);
/* --- */
final JoglFrameBufferObject READ_FBO = _myFBO;
_myShaderManager.setUniform(
_myPointSpriteShader,
"textureVelocity",
READ_FBO.additional_texture(BufferInfo.SECONDARY).getTextureUnit() - GL.GL_TEXTURE0);
_myShaderManager.setUniform(_myPointSpriteShader, "velocityThreshold", velocity_threshold);
_myShaderManager.setUniform(_myPointSpriteShader, "sizeThreshold", size_threshold);
_myShaderManager.setUniform(_myPointSpriteShader, "pointSize", point_size);
_myShaderManager.setUniform(_myPointSpriteShader, "flowdirection", flow_direction);
_myShaderManager.setUniform(_myPointSpriteShader, "collisionratio", collision_ratio);
gl.glActiveTexture(READ_FBO.additional_texture(BufferInfo.SECONDARY).getTextureUnit());
gl.glBindTexture(
READ_FBO.additional_texture(BufferInfo.SECONDARY).getTextureTarget(),
READ_FBO.additional_texture(BufferInfo.SECONDARY).getTextureID());
JoglUtil.printGLError(gl, glu, "binding texture", true);
gl.glDrawArrays(GL.GL_POINTS, 0, w * h);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, 0);
gl.glDisableClientState(GL.GL_VERTEX_ARRAY);
gl.glDisableVertexAttribArray(myPointSizeAttrib);
_myShaderManager.disable();
gl.glDisable(GL.GL_VERTEX_PROGRAM_POINT_SIZE_ARB);
gl.glBindTexture(READ_FBO.additional_texture(BufferInfo.SECONDARY).getTextureTarget(), 0);
JoglUtil.printGLError(gl, glu, "display()", true);
}
private void createVBO(GL gl, GLU glu, JoglFrameBufferObject theFBO) {
final int w = theFBO.getPixelWidth();
final int h = theFBO.getPixelHeight();
// setup buffer object for 4 floats per item
int[] tmp = new int[1];
gl.glGenBuffers(1, tmp, 0);
_myVBO = tmp[0];
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, _myVBO);
gl.glBufferData(
GL.GL_ARRAY_BUFFER, w * h * 4 * BufferUtil.SIZEOF_FLOAT, null, GL.GL_STREAM_COPY);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, 0);
/* create float buffer for pointsizes */
float[] myValues = new float[w * h * 3];
for (int i = 0; i < myValues.length; i += 3) {
myValues[i + 0] = (i / 3) % w; // x
myValues[i + 1] = (i / 3) / w; // y
myValues[i + 2] = (float) Math.random() * 1; // pointsize
}
gl.glGenBuffers(1, tmp, 0);
_myIBO = tmp[0];
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, _myIBO);
gl.glBufferData(
GL.GL_ARRAY_BUFFER,
w * h * 3 * BufferUtil.SIZEOF_FLOAT,
FloatBuffer.wrap(myValues),
GL.GL_STATIC_DRAW);
gl.glBindBuffer(GL.GL_ARRAY_BUFFER, 0);
/* check for errors */
JoglUtil.printGLError(gl, glu, getClass().getSimpleName() + ".createVBO()", true);
}