protected void beginDrawAnnotations(DrawContext dc, OGLStackHandler stackHandler)
{
GL2 gl = dc.getGL().getGL2(); // GL initialization checks for GL2 compatibility.
int attributeMask = GL2.GL_COLOR_BUFFER_BIT // for alpha test func and ref, blend func
| GL2.GL_CURRENT_BIT // for current color
| GL2.GL_DEPTH_BUFFER_BIT // for depth test, depth mask, depth func
| GL2.GL_ENABLE_BIT // for enable/disable changes
| GL2.GL_HINT_BIT // for line smoothing hint
| GL2.GL_LINE_BIT // for line width, line stipple
| GL2.GL_TRANSFORM_BIT // for matrix mode
| GL2.GL_VIEWPORT_BIT; // for viewport, depth range
stackHandler.pushAttrib(gl, attributeMask);
// Load a parallel projection with dimensions (viewportWidth, viewportHeight)
stackHandler.pushProjectionIdentity(gl);
gl.glOrtho(0d, dc.getView().getViewport().width, 0d, dc.getView().getViewport().height, -1d, 1d);
// Push identity matrices on the texture and modelview matrix stacks. Leave the matrix mode as modelview.
stackHandler.pushTextureIdentity(gl);
stackHandler.pushModelviewIdentity(gl);
// Enable the alpha test.
gl.glEnable(GL2.GL_ALPHA_TEST);
gl.glAlphaFunc(GL2.GL_GREATER, 0.0f);
// Apply the depth buffer but don't change it.
if ((!dc.isDeepPickingEnabled()))
{
gl.glEnable(GL.GL_DEPTH_TEST);
}
gl.glDepthMask(false);
// Disable lighting and backface culling.
gl.glDisable(GL2.GL_LIGHTING);
gl.glDisable(GL.GL_CULL_FACE);
if (!dc.isPickingMode())
{
// Enable blending in premultiplied color mode.
gl.glEnable(GL.GL_BLEND);
OGLUtil.applyBlending(gl, true);
}
else
{
this.pickSupport.beginPicking(dc);
}
}
/**
* Configures the GL attached to the specified DrawContext for rendering a 2D model to a texture. The modelview
* matrix is set to the identity, the projection matrix is set to an orthographic projection aligned with the
* specified draw rectangle (x, y, width, height), the viewport and scissor boxes are set to the specified draw
* rectangle, and the depth test and depth write flags are disabled. Because the viewport and scissor boxes are set
* to the draw rectangle, only the texels intersecting the specified drawing rectangle (x, y, width, height) are
* affected by GL commands. Once rendering is complete, this should always be followed with a call to {@link
* #endRendering(gov.nasa.worldwind.render.DrawContext)}.
*
* @param dc the current DrawContext.
* @param x the x-coordinate of the draw region's lower left corner.
* @param y the y-coordinate of the draw region's lower left corner.
* @param width the draw region width.
* @param height the draw region height.
*
* @throws ArgumentException if the DrawContext is null.
*/
public void beginRendering(DrawContext dc, int x, int y, int width, int height)
{
if (dc == null)
{
String message = Logging.getMessage("nullValue.DrawContextIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
GL2 gl = dc.getGL().getGL2(); // GL initialization checks for GL2 compatibility.
this.drawRegion = new java.awt.Rectangle(x, y, width, height);
// Note: there is no attribute bit for framebuffer objects. The default framebuffer object state (object ID 0
// is bound as the current fbo) is restored in endRendering().
this.stackHandler.pushAttrib(gl,
GL2.GL_COLOR_BUFFER_BIT // For clear color.
| GL2.GL_DEPTH_BUFFER_BIT // For depth test and depth mask.
| GL2.GL_SCISSOR_BIT // For scissor test and scissor box.
| GL2.GL_TRANSFORM_BIT // For matrix mode.
| GL2.GL_VIEWPORT_BIT); // For viewport state.
this.stackHandler.pushTextureIdentity(gl);
this.stackHandler.pushProjectionIdentity(gl);
gl.glOrtho(x, x + width, y, y + height, -1, 1);
this.stackHandler.pushModelviewIdentity(gl);
// Disable the depth test and writing to the depth buffer. This provides consistent render to texture behavior
// regardless of whether we are using copy-to-texture or framebuffer objects. For copy-to-texture, the depth
// test and depth writing are explicitly disabled. For fbos there is no depth buffer components, so the depth
// dest is implicitly disabled.
gl.glDisable(GL.GL_DEPTH_TEST);
gl.glDepthMask(false);
// Enable the scissor test and set both the scissor box and the viewport to the specified region. This enables
// the caller to set up rendering to a subset of the texture. Note that the scissor box defines the region
// affected by a call to glClear().
gl.glEnable(GL.GL_SCISSOR_TEST);
gl.glScissor(x, y, width, height);
gl.glViewport(x, y, width, height);
if (this.useFramebufferObject(dc))
{
this.beginFramebufferObjectRendering(dc);
}
}
