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cf_text_effect_register

Category: text
GitHub: cute_draw.h

Registers a custom text effect.

void cf_text_effect_register(const char* name, CF_TextEffectFn* fn);
Parameters Description
name A unique name for your text effect.
fn The CF_TextEffectFn function you must implement to perform the custom effect.

Code Example

Internally the text shake effect is implemented something like this.

// Given a string like this:
"Some <shake freq=50 x=2.5 y=1>shaking text</shake> drawing!"

static bool s_text_fx_shake(TextEffect* effect)
{
    double freq = effect->get_number("freq", 35);
    int seed = (int)(effect->elapsed * freq);
    float x = (float)effect->get_number("x", 2);
    float y = (float)effect->get_number("y", 2);
    CF_Rnd rnd = cf_rnd_seed(seed);
    v2 offset = V2(rnd_next_range(rnd, -x, y), rnd_next_range(rnd, -x, y));
    effect->q0 += offset;
    effect->q1 += offset;
    return true;
}

// Register it like so:
cf_text_effect_register("shake", s_text_fx_shake);

Remarks

The name of the text effect will be used within the string text codes. For example, for the "shake" effect in the above example, the text code will be used. 

+ color
     example : "Here's some <color=#2c5ee8>blue text</color>."
             : default (white) - The color to render text with.
+ shake
     example : "<shake freq=30 x=3 y=3>This text is all shaky.</shake>"
     example : "<shake y=20>Shake this text with default values, but override for a big height.</shake>"
     freq    : default (35)    - Number of times per second to shake.
     x       : default (2)     - Max +/- distance to shake on x-axis.
     y       : default (2)     - Max +/- distance to shake on y-axis.
+ fade
     example : "<fade speed=10 span=3>Fading some text like a ghost~</fade>"
     example : "<fade>Fading some text like a ghost~</fade>"
     speed   : default (2)     - Number of times per second to find in and then out.
     span    : default (5)     - Number of characters long for the fade to loop.
+ wave
     example : "<wave>Wobbly wave text.</wave>"
     speed   : default (5)     - Number of times per second to bob up and down.
     span    : default (10)    - Number of characters long for the wave to loop.
     height  : default (5)     - How many characters high the wave will go.
+ strike
     example : "<strike>Strikethrough</strike>"
     example : "<strike=10>Thick Strikethrough</strike>"
             : default (font_height / 20) - The thickness of the strike line.
+ font
     example : "<font name=\"MyBold\" size=48>Big bold text</font>"
     example : "<font size=32>Larger text, same face</font>"
     name    : (optional string) - Name of a font previously loaded with `cf_make_font` (or `font` as an alias key). Omit to keep the current face and only change size.
     size    : (optional number) - Pixel size to use for this span. A line's height, baseline, and measured
               size (see `cf_text_size`) grow to fit the largest size on that line, so large spans stay inside
               the reported bounds and successive lines don't collide. Animated effects (wave/shake) are not
               counted in measurement. Note: vertical text (`cf_push_text_vertical_layout`) uses base-face columns.
When registering a custom text effect, any parameters in the string will be stored for you automatically. You only need to fetch them with the appropriate cf_text_effect_get*** function. Note: You can also setup parameters for markup as strings, not just numbers/colors. Example: <color=#2c5ee8 metadata=\"Just some string.\">blue text</color>, where the color markup contains a parameter called metadata and a string value of "Just some string.".

For bold/italic style tags, load the corresponding font faces and map them with cf_text_effect_set_font (bold/italic are separate fonts, not runtime styles). Example: 

cf_make_font("fonts/Calibri-Bold.ttf", "Calibri Bold");
cf_text_effect_set_font("b", "Calibri Bold");
cf_draw_text("Hello <b>bold</b> world", pos, -1);

CF_TextEffect
CF_TextEffectFn
cf_text_effect_get_string
cf_text_effect_set_font
cf_text_effect_get_number
cf_text_effect_get_color