Every once in a while I reappear with an issue I can't solve which then is solved within merely 3 posts. I hope this is one of those.

 

Anyway, my issue is that despite using Vanilla code under some circumstances Minecraft will render a "background" for my custom item. The background appears to be an approximately 10 times larger version of the rendered item. The conditions for this misbehavior are simple: if the first non-empty inventory slot is a non-block item, the background will be rendered. If, for example, I "pick up" the item, i.e. click it once in order to move it to a different slot, the background quickly disappears.

 

Here's some relevant code.

@Override
public void render( ItemRenderType type, ItemStack itemStack, Object... data ) {
IIcon icon = MiscHelper.getItemIcon("stick"); // Just trust me on this one. It gets the IIcon correctly as you can see in the screenshot...

// Inventory coordinates go from 0d to 16d in both x and y coordinates. Plus we don't need to render the sides, just the image.
if( type == ItemRenderType.INVENTORY ) {
	renderItemInInventory(Tessellator.instance, icon);
}
// Everything else goes from 0d to 1d.
else {
	renderItemIn2D(Tessellator.instance, icon, 0.0625d);
}
}

protected void renderItemInInventory( Tessellator tess, IIcon icon ) {
// This call increases the scale for the first two methods here.
//	GL11.glScalef(16f, 16f, 16f);

// Doesn't fucking matter if I use this...
//	renderItemIn2D(tess, icon.getMinU(), icon.getMinV(), icon.getMaxU(), icon.getMaxV(), icon.getIconWidth(), icon.getIconHeight(), 0.0625d);

// Or this...
//	ItemRenderer.renderItemIn2D(tess, icon.getMinU(), icon.getMinV(), icon.getMaxU(), icon.getMaxV(), icon.getIconWidth(), icon.getIconHeight(), (float)0.0625f);

// Or even my own algorithm to render the item in the inventory.
renderItemInInventory(tess, icon.getMinU(), icon.getMinV(), icon.getMaxU(), icon.getMaxV());

// They all end up with an unwanted background under certain circumstances.
}

protected void renderItemInInventory( Tessellator tess, double u1, double v1, double u2, double v2 ) {
tess.startDrawingQuads();
if( baseColor != -1 ) tess.setColorOpaque_I(baseColor);
tess.addVertexWithUV( 0d,  0d, 0d, u1, v1);
tess.addVertexWithUV( 0d, 16d, 0d, u1, v2);
tess.addVertexWithUV(16d, 16d, 0d, u2, v2);
tess.addVertexWithUV(16d,  0d, 0d, u2, v1);
tess.draw();
}

 

My code should differ in no way when only calling ItemRenderer.renderItemIn2D since that is ultimately what happens in the Vanilla ItemRenderer:

 

            texturemanager.bindTexture(texturemanager.getResourceLocation(p_78443_2_.getItemSpriteNumber()));
            TextureUtil.func_152777_a(false, false, 1.0F);
            Tessellator tessellator = Tessellator.instance;
            float f = iicon.getMinU();
            float f1 = iicon.getMaxU();
            float f2 = iicon.getMinV();
            float f3 = iicon.getMaxV();
            float f4 = 0.0F;
            float f5 = 0.3F;
            GL11.glEnable(GL12.GL_RESCALE_NORMAL);
            GL11.glTranslatef(-f4, -f5, 0.0F);
            float f6 = 1.5F;
            GL11.glScalef(f6, f6, f6);
            GL11.glRotatef(50.0F, 0.0F, 1.0F, 0.0F);
            GL11.glRotatef(335.0F, 0.0F, 0.0F, 1.0F);
            GL11.glTranslatef(-0.9375F, -0.0625F, 0.0F);

            // Code before and after this call is part of the ForgeHooksClient which actually calls the custom ItemRenderer.render method.
            renderItemIn2D(tessellator, f1, f2, f, f3, iicon.getIconWidth(), iicon.getIconHeight(), 0.0625F);

            if (p_78443_2_.hasEffect(p_78443_3_))
            {
                GL11.glDepthFunc(GL11.GL_EQUAL);
                GL11.glDisable(GL11.GL_LIGHTING);
                texturemanager.bindTexture(RES_ITEM_GLINT);
                GL11.glEnable(GL11.GL_BLEND);
                OpenGlHelper.glBlendFunc(768, 1, 1, 0);
                float f7 = 0.76F;
                GL11.glColor4f(0.5F * f7, 0.25F * f7, 0.8F * f7, 1.0F);
                GL11.glMatrixMode(GL11.GL_TEXTURE);
                GL11.glPushMatrix();
                float f8 = 0.125F;
                GL11.glScalef(f8, f8, f8);
                float f9 = (float)(Minecraft.getSystemTime() % 3000L) / 3000.0F * 8.0F;
                GL11.glTranslatef(f9, 0.0F, 0.0F);
                GL11.glRotatef(-50.0F, 0.0F, 0.0F, 1.0F);
                renderItemIn2D(tessellator, 0.0F, 0.0F, 1.0F, 1.0F, 256, 256, 0.0625F);
                GL11.glPopMatrix();
                GL11.glPushMatrix();
                GL11.glScalef(f8, f8, f8);
                f9 = (float)(Minecraft.getSystemTime() % 4873L) / 4873.0F * 8.0F;
                GL11.glTranslatef(-f9, 0.0F, 0.0F);
                GL11.glRotatef(10.0F, 0.0F, 0.0F, 1.0F);
                renderItemIn2D(tessellator, 0.0F, 0.0F, 1.0F, 1.0F, 256, 256, 0.0625F);
                GL11.glPopMatrix();
                GL11.glMatrixMode(GL11.GL_MODELVIEW);
                GL11.glDisable(GL11.GL_BLEND);
                GL11.glEnable(GL11.GL_LIGHTING);
                GL11.glDepthFunc(GL11.GL_LEQUAL);
            }

            GL11.glDisable(GL12.GL_RESCALE_NORMAL);
            texturemanager.bindTexture(texturemanager.getResourceLocation(p_78443_2_.getItemSpriteNumber()));
            TextureUtil.func_147945_b();

 

 

Does anybody have an idea why this happens..? I could probably work this out without a custom ItemRenderer. After digging around somewhat in the code I found out that you can return a color from the ItemStack. Yet I really want to find out how and why this happens.

 

Sincerely ~

 

Screenshot of the bug:

Hi

 

I reckon it might be an OpenGL render setting carrying over from the last thing that got drawn.  Alpha test is a typical suspect, there are others.

 

I wrote a small tool that I've used in the past to check what the OpenGL settings are; it's not complete, but dumpAllIsEnabled() works and has showed up problems for me before- dump for a good render, dump for a bad render, and spot the difference.  It might be worth a go.

 

https://github.com/TheGreyGhost/SpeedyTools/blob/master/src/speedytools/common/utilities/OpenGLdebugging.java

 

-TGG

 

Thank God!

 

Thanks to you and your tool I finally found the error. It indeed was the lack of Alpha Testing. Now that I set the flag OpenGL renders the intended background of the hotbar / inventory. This issue made me mad the last 4 days... Once again my issue could be solved within 3 posts, counting mine as well.

 

Cheers!

No worries, glad I could help