1 files changed, 121 insertions, 0 deletions
diff --git a/lpg/libqr/code-create.c b/lpg/libqr/code-create.c
new file mode 100644
index 0000000..d09c2fe
--- /dev/null
+++ b/lpg/libqr/code-create.c
@@ -0,0 +1,121 @@
+#include <stdlib.h>
+#include <limits.h>
+#include <assert.h>
+#include <qr/code.h>
+
+#include "code-common.h"
+#include "data-common.h"
+
+#define MIN(a, b) ((b) < (a) ? (b) : (a))
+
+#include <stdio.h>
+static void x_dump(struct bitstream * bits)
+{
+        size_t i, n;
+
+        bitstream_seek(bits, 0);
+        n = bitstream_size(bits);
+        for (i = 0; i < n; ++i) {
+                printf("%d", bitstream_read(bits, 1));
+                if (i % 8 == 7)
+                        printf(" ");
+                if ((i+1) % (7 * 8) == 0)
+                        printf("\n");
+        }
+        printf("\n");
+}
+
+static int add_ecc(struct bitstream * bits, int format, enum qr_ec_level ec)
+{
+        puts("Before ecc:");
+        x_dump(bits);
+
+        return -1;
+}
+
+static int pad_data(struct bitstream * bits, size_t limit)
+{
+        /* This function is not very nice. Sorry. */
+
+        size_t count, n;
+
+        assert(bitstream_size(bits) <= limit);
+
+        if (bitstream_resize(bits, limit) != 0)
+                return -1;
+
+        n = bitstream_size(bits);
+        bitstream_seek(bits, n);
+        count = limit - n;
+
+        /* First append the terminator (0000) if possible,
+         * and pad with zeros up to an 8-bit boundary
+         */
+        n = (n + 4) % 8;
+        if (n != 0)
+                n = 8 - n;
+        n = MIN(count, n + 4);
+        bitstream_write(bits, 0, n);
+        count -= n;
+
+        assert(count % 8 == 0); /* since data codewords are 8 bits */
+
+        /* Finally pad with the repeating sequence 11101100 00010001 */
+        while (count >= 16) {
+                bitstream_write(bits, 0xEC11, 16);
+                count -= 16;
+        }
+        if (count > 0) {
+                assert(count == 8);
+                bitstream_write(bits, 0xEC, 8);
+        }
+
+        return 0;
+}
+
+static struct bitstream * make_data(int                format,
+                                    enum qr_ec_level   ec,
+                                    struct bitstream * data)
+{
+        size_t data_bits = 16 * 8 /*XXX*/;
+        struct bitstream * out;
+
+        out = bitstream_copy(data);
+        if (!out)
+                return 0;
+
+        if (pad_data(out, data_bits) != 0)
+                goto fail;
+
+        if (add_ecc(out, format, ec) != 0)
+                goto fail;
+
+        return out;
+fail:
+        bitstream_destroy(out);
+        return 0;
+}
+
+struct qr_code * qr_code_create(enum qr_ec_level       ec,
+                                const struct qr_data * data)
+{
+        struct qr_code * code;
+        struct bitstream * ecdata;
+
+        code = malloc(sizeof(*code));
+        if (!code)
+                return 0;
+
+        code->format = data->format;
+        ecdata = make_data(data->format, ec, data->bits);
+
+        if (!ecdata) {
+                free(code);
+                return 0;
+        }
+
+        /* TODO: allocate bitmap; layout */
+
+        return 0;
+}
+