Font quality in Linux

[spworley]

Running Ubuntu with the latest GLWF 3.0.4, fonts are very poorly rendered. The rightmost column of each glyph is clipped off, and the y baseline of each glyph is not consistent.

[ocornut]

In this function
void ImBitmapFont::RenderText(

You can replace

            const float s1 = (0.0f + glyph->X) * tex_scale_x;
            const float t1 = (0.0f + glyph->Y) * tex_scale_y;
            const float s2 = (0.0f + glyph->X + glyph->Width) * tex_scale_x;
            const float t2 = (0.0f + glyph->Y + glyph->Height) * tex_scale_y;

With

            const float s1 = (0.5f + glyph->X) * tex_scale_x;
            const float t1 = (0.5f + glyph->Y) * tex_scale_y;
            const float s2 = (0.5f + glyph->X + glyph->Width) * tex_scale_x;
            const float t2 = (0.5f + glyph->Y + glyph->Height) * tex_scale_y;

I am currently investigating the right way to expose that because the offset depends on your rendering architecture.

[ocornut]

I have commited a fix, added a 'float PixelCenterOffset' value in ImGuiIO which default to 0.5f (for OpenGL and DirectX 10+). The DirectX9 sample application sets it back to 0.0. Based on a suggestion by SimDietrich.