Add a way to specify text style in text codes, such as bold or italic

[RandyGaul]

As per discord discussion, so far this made a lot of sense:

cf_text_effect_set_font(const char* effect_name, const char* font);

We can add a font field to the internal effect that gets registered:

struct CF_TextEffectDefinition {
  const char* font_override;
  CF_TextEffectFn fn;
}

For a particular effect that has not been registered, we can just auto-register a stub function pointer to get the text code working. Example use:

cf_text_effect_set_font("b", "calibri bold");

// ...

cf_draw_text("<b>bold</b>", ...);

[ogam]

Currently the text xadvance is though a lambda, would we be able to override the xadvance / kerning in text effect callbacks to handle bold and italics fonts since those can have different values?

auto advance_to_next_glyph = [&](CF_Glyph* last_glyph) {
		// Max bound covers the entire glyph without kerning so we use w instead
		// of xadvance
		max_x = max(max_x, x + last_glyph->w);
		if (vertical) {
			min_y = min(min_y, y + font->descent * scale);

			y -= line_height;
		} else {
			x += last_glyph->xadvance;
		}
	};

[RandyGaul]

Maybe those local variables need to put into a struct, and have a couple instances of that struct for different fonts. Then pass in the style param struct into the lambda (or capture it maybe). What do you think?

[ogam]

I think that would work for bold and italics case, would that support something like below or would this be out of scope?

cf_push_font_size(48);
cf_draw_text("what the <font name=\"some_exaggerated_font\" size=64><b><i>COW!?</i></b></font>", cf_v2(0, 0), -1);
cf_pop_font_size();

i don't have a usage case for this but not sure if anyone is doing any heavy text based some like a visual novel where they would need this.

[RandyGaul]

I think we should treat bold and italic like any other font, so yes definitely support swapping fonts like that