dino/plugins/omemo/vapi/libqrencode.vapi

81 lines
3 KiB
Vala

[CCode (cheader_filename = "qrencode.h")]
namespace Qrencode {
[CCode (cname = "QRecLevel", cprefix = "QR_ECLEVEL_")]
public enum ECLevel {
L,
M,
Q,
H
}
[CCode (cname = "QRencodeMode", cprefix = "QR_MODE_")]
public enum EncodeMode {
NUL,
NUM,
AN,
[CCode (cname = "QR_MODE_8")]
EIGHT_BIT,
KANJI,
STRUCTURE,
ECI,
FNC1FIRST,
FNC1SECOND
}
[CCode (cname = "QRcode", free_function = "QRcode_free", has_type_id = false)]
[Compact]
public class QRcode {
private int version;
private int width;
[CCode (array_length = false)]
private uint8[] data;
[CCode (cname = "QRcode_encodeString")]
public QRcode (string str, int version = 0, ECLevel level = ECLevel.L, EncodeMode hint = EncodeMode.EIGHT_BIT, bool casesensitive = true);
public Gdk.Paintable to_paintable(int module_size) {
GLib.assert(module_size > 0);
var dst_width = width*module_size;
var dst_data = new uint8[dst_width*dst_width*3];
expand_and_upsample(data,width,width, dst_data,dst_width,dst_width);
return new Gdk.MemoryTexture(dst_width, dst_width, Gdk.MemoryFormat.R8G8B8,
new GLib.Bytes.take((owned) dst_data), dst_width*3);
}
/** Does 2D nearest-neighbor upsampling of an array of single-byte
* samples, while expanding the least significant bit of each sample
* to three 0-or-255 bytes.
*/
private void expand_and_upsample(
uint8[] src, uint src_w, uint src_h,
uint8[] dst, uint dst_w, uint dst_h) {
GLib.assert(dst_w % src_w == 0);
GLib.assert(dst_h % src_h == 0);
var scale_x = dst_w/src_w,
scale_y = dst_h/src_h;
/* Doing the iteration in the order of destination samples for
* improved cache-friendliness (dst is 48 times larger than src in
* the typical case of scaling by 4x4).
* The choice of multiple nested loops over a single one is for
* avoiding a ton of divisions by non-constants.
*/
for (uint src_y = 0; src_y < src_h; ++src_y) {
for (uint repeat_y = 0; repeat_y < scale_y; ++repeat_y) {
var dst_y = src_y*scale_y + repeat_y;
for (uint src_x = 0; src_x < src_w; ++src_x) {
uint8 value = (src[src_y*src_w + src_x] & 1)==1 ? 0:255;
for (uint repeat_x = 0; repeat_x < scale_x; ++repeat_x){
var dst_x = src_x*scale_x + repeat_x;
var dst_idx = dst_y*dst_w + dst_x;
dst[dst_idx*3+0] = value;
dst[dst_idx*3+1] = value;
dst[dst_idx*3+2] = value;
}
}
}
}
}
}
}