I know I'm probably an idiot for doing it like this but here it is anyway:

 

With ModLoader's onTickInGame method, I would just set the hook to send partial ticks, and the overlay would work. When using FML, I am getting severe flicker. I have tried using different tick types, with no success.

 

            mc.gameSettings.hideGUI = true;
            ScaledResolution scaledresolution = new ScaledResolution(mc.gameSettings, mc.displayWidth, mc.displayHeight);
            int i = scaledresolution.getScaledWidth();
            int k = scaledresolution.getScaledHeight();
            mc.entityRenderer.setupOverlayRendering();
            GL11.glEnable(GL11.GL_BLEND);
            GL11.glDisable(GL11.GL_DEPTH_TEST);
            GL11.glDepthMask(false);
            GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
            GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
            GL11.glDisable(GL11.GL_ALPHA_TEST);
            GL11.glBindTexture(GL11.GL_TEXTURE_2D, mc.renderEngine.getTexture("/Mic'sMods/CrossbowMod/gui/attachmentShortScope.png"));
            Tessellator tessellator = Tessellator.instance;
            tessellator.startDrawingQuads();
            tessellator.addVertexWithUV(i / 2 - 2 * k, k, -90D, 0.0D, 1.0D);
            tessellator.addVertexWithUV(i / 2 + 2 * k, k, -90D, 1.0D, 1.0D);
            tessellator.addVertexWithUV(i / 2 + 2 * k, 0.0D, -90D, 1.0D, 0.0D);
            tessellator.addVertexWithUV(i / 2 - 2 * k, 0.0D, -90D, 0.0D, 0.0D);
            tessellator.draw();
            GL11.glDepthMask(true);
            GL11.glEnable(GL11.GL_DEPTH_TEST);
            GL11.glEnable(GL11.GL_ALPHA_TEST);
            GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);

 

What do I need to do to get a non-flickering game overlay?

 

Thanks.

I was getting flickering with my HUD but a few small tweaks to my tick handler and all was good.

My handler code can be found in the tutorial, using the onRenderTick() fix my flicker and should work for you.

 

http://www.minecraftforge.net/wiki/Tutorials/Upgrading_To_Forge_for_1.3.1#Ticking