From ea223a23503c80759d5579626285eda0e617d6b4 Mon Sep 17 00:00:00 2001 From: Ben Harris Date: Mon, 5 Dec 2022 19:34:09 +0000 Subject: [PATCH] js: Put the puzzle background colour in a CSS variable It's sometimes useful to be able to have an HTML element that visually forms an extension of the puzzle's border. By putting the puzzle's colour 0 (which we assume to be its background) into a CSS variable, such elements can do something like "background-color: var(--puzzle-background)" to get that effect even if the puzzle uses a non-default background colour. --- emcc.c | 3 +++ emcclib.js | 11 +++++++++++ 2 files changed, 14 insertions(+) diff --git a/emcc.c b/emcc.c index 98d5cea..1d88bfd 100644 --- a/emcc.c +++ b/emcc.c @@ -51,6 +51,7 @@ extern void js_add_preset(int menuid, const char *name, int value); extern int js_add_preset_submenu(int menuid, const char *name); extern int js_get_selected_preset(void); extern void js_select_preset(int n); +extern void js_set_background_colour(const char *bg); extern void js_get_date_64(unsigned *p); extern void js_update_permalinks(const char *desc, const char *seed); extern void js_enable_undo_redo(bool undo, bool redo); @@ -1007,6 +1008,8 @@ int main(int argc, char **argv) (unsigned)(0.5 + 255 * colours[i*3+2])); colour_strings[i] = dupstr(col); } + /* Put the background colour in a CSS variable. */ + js_set_background_colour(colour_strings[0]); /* * Request notification when the game ids change (e.g. if the user diff --git a/emcclib.js b/emcclib.js index 3824293..814ff56 100644 --- a/emcclib.js +++ b/emcclib.js @@ -143,6 +143,17 @@ mergeInto(LibraryManager.library, { menuform.elements["preset"].value = n; }, + /* + * void js_set_background_colour(const char *bg); + * + * Record the puzzle background colour in a CSS variable so + * the style sheet can use it if it wants. + */ + js_set_background_colour: function(bgptr) { + document.documentElement.style.setProperty("--puzzle-background", + UTF8ToString(bgptr)); + }, + /* * void js_get_date_64(unsigned *p); *