Scaling fonts

[CrashOverride85]

Is there a way to scale up existing fonts, i.e. use one of the supplied fonts at double/triple etc., the actual size? If not, would a PR that adds this be reasonable?
I'm thinking versions of hagl_put_text / hagl_put_char that take a scale factor as a parameter.

[tuupola]

Currently there is no convenient way but you could use hagl_scale_blit(). Below example blits random 6x9 chars as 24x36.

bitmap_t bitmap;
bitmap.buffer = (uint8_t *) malloc(6 * 9 * sizeof(color_t));

for (uint16_t i = 1; i < 20000; i++) {
    int16_t x0 = rand() % DISPLAY_WIDTH;
    int16_t y0 = rand() % DISPLAY_HEIGHT;
    color_t color = rand() % 0xffff;
    uint16_t code = rand() % 0xffff;
    hagl_get_glyph(code, color, &bitmap, font6x9);
    hagl_scale_blit(x0, y0, 24, 36, &bitmap);
}

I have intentionally left scaled fonts out for now because I have not figured out a good API on how to do it. Lets assume we add a scaling factor.

hagl_put_char(code, x0, y0, color, font8x8, scale);

Still quite ok, but what about background color?

hagl_put_char(code, x0, y0, color, background, font8x8, scale);

What is we need be able to put chars rotated 90 degrees?

hagl_put_char(code, x0, y0, color, background, font8x8, scale, rotate);

etc. In the end there will be too many parameters and the code will look ugly. One option would be to add a style struct.

font_style_t style;

style.font = font8x8;
style.scale = 2;
style.color = rand() % 0xffff;

hagl_put_char(code, x0, y0, style);

This way it would be easy to maintain BC even when adding new stylable parameters. Question is should other functions such as hagl_draw_line() use style struct instead of simple color?

Other possibility would be to use builder style functions.

hagl_set_font(font8x8);
hagl_set_font_scale(2);
hagl_set_font_color(0xffff);
hagl_put_char(code, x0, y0);

Or maybe use actual builders.

font_style_t style;

hagl_set_font(font8x8, &style);
hagl_set_font_scale(2, &style);
hagl_set_font_color(0xffff, &style);
hagl_put_char(code, x0, y0, style);

I think I personally like the first option ie. style structs most.

[CrashOverride85]

hmmm, ok, thanks, I see what you mean. Not quite as simple as it first seems if you don't want to get into a mess in the future

[tuupola]

In the meanwhile if you just need bigger fonts check for example the X11 fonts.

[CrashOverride85]

Thanks for the suggestion...
Having thought about it, I think I'm really going to need font scaling for what I'm planning, as I'm going to be wanting to use a few different sizes, up to a size where 1 or 2 digits pretty much fills the screen.
A style struct seems a pretty nice way of doing it, so I can go for that.
If I make these changes (and they end up being neat enough, following coding standards, etc), is this something you'd be interested in merging in at some point? If so I'll make an effort to do to properly lol
If not then no worries, I might keep the code outside of hagl so I can keep on master. Having said that, it might be a while until I get around to it anyway :/

The biggest problem I can see is that adding style (or anything) to the existing hagl_put_char, etc., functions is that it'd be a breaking change to the API?