With the stencil buffer in opengl-es for Android, I'm simply trying to mask out drawing part of the screen. I think I have it set up right, but it is not masking out the non-stenciled parts. Below is an extraction of code for what I'm doing.
gl.glEnable(GL10.GL_STENCIL_TEST);
gl.glClearStencil(0);
gl.glClear(GL10.GL_STENCIL_BUFFER_BIT);
gl.glColorMask(false, false, false, false);
gl.glDepthMask(false);
gl.glStencilFunc(GL10.GL_ALWAYS, 1, 1);
gl.glStencilOp(GL10.GL_REPLACE, GL10.GL_REPLACE, GL10.GL_REPLACE);
drawMask(); //I have confirmed this draws to the correct location by allowing colour to show. Trust that this draws the mask to the correct location.
gl.glColorMask(true, true, true, true);
gl.glDepthMask(true);
gl.glStencilFunc(GL10.GL_EQUAL, 1, 1);
gl.glStencilOp(GL10.GL_KEEP, GL10.GL_KEEP, GL10.GL_KEEP);
drawItems(); //Draw everything. Only items inside the masked area should be drawn. But everything is drawn with this code...
gl.glDisable(GL10.GL_STENCIL_TEST);
Anyone spot anything wrong with this? What it does basically is draw a box for say, half the screen (this works if I had colour enabled) which is setting the stencil buffer to 1 for that area. And at the end I draw to the whole screen. I want it to draw to the top half only, but it draws everything.
Thanks in advance.
You have to set the stencilSize using setEGLConfigChooser. Note that different phones have different surfaces which may or may not support this.
For example:
// void android.opengl.GLSurfaceView.setEGLConfigChooser(int redSize, int greenSize, int blueSize, int alphaSize, int depthSize, int stencilSize)
mGLSurfaceView.setEGLConfigChooser(8, 8, 8, 8, 16, 8);