Font Rendering

[SpiderPig]

I'm not using the default widget system here, I've made my own and rasterize my fonts to a texture.  In this screenshot you can clearly see the problem I have.  I added a background shader to the font shader.  The text only looks good when on dark backgrounds.  You can see the right side is much nicer than the left side.

Here's my inventory.

I'm unsure if this is a font shader issue - a rasterization issue - or simply I need better font colours depending on the background color.  Thought I'd ask to see if any one here might have any tips.

[SpiderPig]

@Josh Do you do anything special when rendering font textures?  Or is this simply an artistic issue and I need better contrast between the background and text.

[Josh]

Use TEXTUREFILTER_NEAREST for the filtering argument when you create the texture. Otherwise, if your texcoords aren't 100% perfect it will blur the text.

[SpiderPig]

Oh that helped a lot, thanks.  That's been driving me nuts for ages. 

[SpiderPig]

There's still a difference between the widget fonts and my own.

Mine seem to be a little more bolder.  It's more noticeable at lower font sizes.

This is my rendering of fonts at different fonts sizes from 8 to 38 respectively.

Size 8 (the first one) is the worst.  I think this might be a hinting issue, although I'm unsure how to get the truetype library to render with hinting if it's not already by default...

[SpiderPig]

Aha, I have solved it.  It was a shader issue.

Old Shader with incorrect way of applying alpha channel.

void main() {
	vec4 tex_sample = texture( sampler2D( materials[ in_MaterialIndex ].textureHandle[ 0 ] ) , in_TexCoords.xy );
	
	color[0] = vec4( 1 , 1 , 1 , tex_sample.x );
	color[0] = ( ( color[0] * tex_sample.x ) * in_Color );
}

New shader with fixed alpha channel.

void main() {
	vec4 tex_sample = texture( sampler2D( materials[ in_MaterialIndex ].textureHandle[ 0 ] ) , in_TexCoords.xy );
	
	color[0] = vec4( in_Color.x , in_Color.y , in_Color.z , tex_sample.x );
	color[0].rgb *= tex_sample.x;
}

@Josh One thing I've never understood is why this "color[0].rgb *= alpha_value" has to be done to achieve transparency?  I thought the alpha component of the vec4 was all that was needed.

[Josh]

Ultra uses pre-multiplied alpha blending. With regular alpha blending the surface in front can only darken the surface behind it. With pre-multiplied, it blends more accurately, and can result in a darker or lighter color.