Loading pattern broken?

[jezdez]

Hey there! Maybe I'm missing something but trying the following on a Keybow mini didn't load the patterns as expected:

keybow.load_pattern("rainbow.png")

keybow.load_pattern("patterns/rainbow.png")

keybow.load_pattern("patterns/rainbow")

local pattern = require "patterns/rainbow.png"
keybow.load_pattern(pattern)

Could someone explain what the correct syntax is for this please?

[Gadgetoid]

Near as I can tell, there's nothing wrong with what you're attempting and a cursory check over the code doesn't yield any obvious problems. I'll try and run a debug build and see if I can replicate.

[jezdez]

But to clarify, it's supposed to be keybow.load_pattern("patterns/rainbow.png") right?

[Gadgetoid]

Ooof, lack of documentation hurts here- it should be:

keybow.load_pattern("patterns/rainbow")

The png part is, for better or worse, added automatically.

A quick local test shows this is at least not failing. Whereas if I try to load patterns/rainbow.png I get the expected:

[read_png_file] File patterns/rainbow.png.png could not be opened for reading

[FleaRex]

Hi both!

This is my minimal working version:

require "keybow"

function handle_key_00(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_01(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_02(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_03(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_04(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_05(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_06(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_07(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_08(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_09(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_10(pressed)
    if pressed then
        load_new_pattern()
    end
end

function handle_key_11(pressed)
    if pressed then
        load_new_pattern()
    end
end

function load_new_pattern()
    keybow.load_pattern('patterns/rainbow')
end

It seemed like keybow.auto_lights(false) was doing something different to what I thought and wouldn't allow load_pattern after getting called.

Two quick Qs

1. Would you like a pull request to add this as an example?
2. It seems like patterns/tropical.png isn't right in the most recent release. Is it worth doing a new release?

[Gadgetoid]

Clearly we need some comprehensive documentation on this functionality-

keybow.auto_lights(false) completely disables the image-based animation sequencing and light patterns in favour of setting individual LEDs manually.

[FleaRex]

Thanks for confirming! Is the C code that the lua code calls around anywhere? It would be interesting to see what keybow.load_pattern and keybow.auto_lights really do. Either way I'm loving it and now that I know what I'm doing it's working really well.

[Gadgetoid]

Absolutely- all the C source is here to browse: https://github.com/pimoroni/keybow-firmware/tree/master/keybow

Here's what keybow.load_pattern boils down to:

keybow-firmware/keybow/lua-config.c

Lines 358 to 374 in 7f359e5

	static int l_load_pattern(lua_State *L) {
	int nargs = lua_gettop(L);
	size_t length;
	const char *pattern = luaL_checklstring(L, 1, &length);
	lua_pop(L, nargs);
	char filename[length + 10];
	sprintf(filename, "%s.png", pattern);
	pthread_mutex_lock(&lights_mutex);
	int result = read_png_file(filename);
	pthread_mutex_unlock(&lights_mutex);
	lua_pushboolean(L, result == 0);
	return 1;
	}

Which, in turn, calls read_png_file in C:

keybow-firmware/keybow/lights.c

Lines 19 to 84 in fd7b19a

	int read_png_file(char* file_name)
	{
	unsigned char header[8]; // 8 is the maximum size that can be checked
	/* open file and test for it being a png */
	FILE *fp = fopen(file_name, "rb");
	if (!fp) {
	abort_("[read_png_file] File %s could not be opened for reading", file_name);
	return 1;
	}
	fread(header, 1, 8, fp);
	if (png_sig_cmp(header, 0, 8)) {
	abort_("[read_png_file] File %s is not recognized as a PNG file", file_name);
	return 1;
	}
	/* initialize stuff */
	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (!png_ptr) {
	abort_("[read_png_file] png_create_read_struct failed");
	return 1;
	}
	info_ptr = png_create_info_struct(png_ptr);
	if (!info_ptr) {
	abort_("[read_png_file] png_create_info_struct failed");
	return 1;
	}
	if (setjmp(png_jmpbuf(png_ptr))) {
	abort_("[read_png_file] Error during init_io");
	return 1;
	}
	png_init_io(png_ptr, fp);
	png_set_sig_bytes(png_ptr, 8);
	png_read_info(png_ptr, info_ptr);
	width = png_get_image_width(png_ptr, info_ptr);
	height = png_get_image_height(png_ptr, info_ptr);
	color_type = png_get_color_type(png_ptr, info_ptr);
	bit_depth = png_get_bit_depth(png_ptr, info_ptr);
	color_channels = png_get_channels(png_ptr, info_ptr);
	number_of_passes = png_set_interlace_handling(png_ptr);
	png_read_update_info(png_ptr, info_ptr);
	/* read file */
	if (setjmp(png_jmpbuf(png_ptr))) {
	abort_("[read_png_file] Error during read_image");
	return 1;
	}
	row_pointers = (png_bytep*) malloc(sizeof(png_bytep) * height);
	for (y=0; y<height; y++)
	row_pointers[y] = (png_byte*) malloc(png_get_rowbytes(png_ptr,info_ptr));
	png_read_image(png_ptr, row_pointers);
	fclose(fp);
	return 0;
	}

And keybow.auto_lights:

keybow-firmware/keybow/lua-config.c

Lines 301 to 307 in 7f359e5

	static int l_auto_lights(lua_State *L) {
	int nargs = lua_gettop(L);
	unsigned short state = lua_toboolean(L, 1);
	lua_pop(L, nargs);
	lights_auto = state;
	return 0;
	}