This code is in MixinContainerScreen and I've tried for RenderGameOverlayEvent.Pre but it is just the same
private final ContainerScreen that = (ContainerScreen) (Object) this;
Method RenderExtraContainer:
private void renderExtraContainer(MatrixStack matrixStack, Slot slot) throws CommandSyntaxException { if (!slot.getStack().isEmpty()) { RenderSystem.disableDepthTest(); RenderSystem.enableBlend(); RenderSystem.enableAlphaTest(); RenderUtils.bindTexture(EXTRA_CONTAINER); AbstractGui.blit(matrixStack, this.that.getGuiLeft() + this.that.getXSize() + 10, this.that.getGuiTop(), 0.0F, 0.0F, 176, 80, 176, 80); RenderSystem.color4f(1.0F, 1.0F, 1.0F, 1.0F); RenderSystem.blendFunc(770, 771); GL11.glTexEnvi(8960, 8704, 3042); GL11.glTexEnvi(8960, 8704, 8448); RenderSystem.enableDepthTest(); RenderSystem.disableAlphaTest(); RenderSystem.enableRescaleNormal(); this.font.drawString(matrixStack, slot.getStack().getDisplayName().getString(), this.that.getGuiLeft() + this.that.getXSize() + 18, this.that.getGuiTop() + 6, FontColor.GRAY.getColorCodes()); ArrayList<ItemStack> listStack = this.getInventoryFromShulkerBoxItem(slot.getStack()); assert this.minecraft != null; ItemRenderer itemRenderer = this.minecraft.getItemRenderer(); int startPointX = this.that.getGuiLeft() + this.that.getXSize() + 18; int startPointY = this.that.getGuiTop() + 18; if (!listStack.isEmpty()) { for (int i = 0; i < 9; i++) { for (int j = 0; j < 3; j++) { if ((i + j * 9) <= listStack.size() - 1) { int count = listStack.get(i + (j * 9)).getCount(); matrixStack.push(); itemRenderer.renderItemAndEffectIntoGUI(listStack.get(i + (j * 9)), startPointX + (i * 18), startPointY + (j * 18)); matrixStack.pop(); if (count > 1) { this.font.drawStringWithShadow(matrixStack, String.valueOf(count), (float) (startPointX + (i * 18) + 16) - this.font.getStringWidth(String.valueOf(count)), (float) (startPointY + (j * 18) + 10), FontColor.WHITE.getColorCodes()); } } } } } } }