1 files changed, 119 insertions, 0 deletions
diff --git a/lpg/libqr/code-render.c b/lpg/libqr/code-render.c
new file mode 100644
index 0000000..cdffe24
--- /dev/null
+++ b/lpg/libqr/code-render.c
@@ -0,0 +1,119 @@
+#include <string.h>
+#include <limits.h>
+#include <assert.h>
+#include <qr/code.h>
+
+#include "code-common.h"
+
+/* CHAR_BIT | mod_bits  (multi-byte) */
+static void render_line_1(unsigned char *       out,
+                          const unsigned char * in,
+                          size_t                mod_bits,
+                          size_t                dim,
+                          unsigned long         mark,
+                          unsigned long         space)
+{
+        unsigned char in_mask;
+        size_t n, b;
+
+        in_mask = 1;
+        n = dim;
+
+        while (n-- > 0) {
+                unsigned long v = (*in & in_mask) ? mark : space;
+
+                if ((in_mask <<= 1) == 0) {
+                        in_mask = 1;
+                        ++in;
+                }
+
+                b = mod_bits / CHAR_BIT;
+                while (b-- > 0) {
+                        *out++ = (unsigned char) v;
+                        v >>= CHAR_BIT;
+                }
+        }
+}
+
+/* mod_bits | CHAR_BIT  (packed) */
+static void render_line_2(unsigned char *       out,
+                          const unsigned char * in,
+                          size_t                mod_bits,
+                          size_t                dim,
+                          unsigned long         mark,
+                          unsigned long         space)
+{
+        unsigned char in_mask;
+        size_t n, b, step, shift;
+
+        in_mask = 1;
+        step = CHAR_BIT / mod_bits;
+        shift = CHAR_BIT - mod_bits;
+        n = dim;
+
+        while (n > 0) {
+                unsigned char tmp = 0;
+
+                b = step;
+                while (b-- > 0) {
+                        unsigned long v = (*in & in_mask) ? mark : space;
+
+                        if ((in_mask <<= 1) == 0) {
+                                in_mask = 1;
+                                ++in;
+                        }
+
+                        tmp = (tmp >> mod_bits) | (v << shift);
+                        if (--n == 0) {
+                                tmp >>= b * mod_bits;
+                                break;
+                        }
+                };
+
+                *out++ = tmp;
+        }
+}
+
+void qr_code_render(const struct qr_code * code,
+                    void *                 buffer,
+                    size_t                 mod_bits,
+                    size_t                 line_stride,
+                    size_t                 line_repeat,
+                    unsigned long          mark,
+                    unsigned long          space)
+{
+        unsigned char * out;
+        const unsigned char * in;
+        size_t n, dim;
+        int pack;
+
+        pack = (mod_bits < CHAR_BIT);
+        assert(!pack || (CHAR_BIT % mod_bits == 0));
+        assert( pack || (mod_bits % CHAR_BIT == 0));
+
+        in = code->modules;
+        out = buffer;
+        dim = qr_code_width(code);
+
+        n = dim;
+        while (n-- > 0) {
+                size_t rpt;
+                unsigned char * next;
+
+                if (pack)
+                        render_line_2(out, in, mod_bits, dim, mark, space);
+                else
+                        render_line_1(out, in, mod_bits, dim, mark, space);
+
+                rpt = line_repeat;
+                next = out + line_stride;
+                while (rpt-- > 0) {
+                        memcpy(next, out, line_stride);
+                        next += line_stride;
+                }
+
+                in += code->line_stride;
+                out = next;
+        }
+}
+