--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/shift.c	Sun Sep 14 09:42:07 2008 +0800
@@ -0,0 +1,99 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "animate.h"
+
+static float comp_mb_timeval_ratio(const mb_timeval_t *a,
+				   const mb_timeval_t *b) {
+    float ratio;
+
+    ratio = (float)MB_TIMEVAL_SEC(a) * 1000000.0 + (float)MB_TIMEVAL_USEC(a);
+    ratio /= (float)MB_TIMEVAL_SEC(b) * 1000000.0 + (float)MB_TIMEVAL_USEC(b);
+    return ratio;
+}
+
+typedef struct _mb_shift mb_shift_t;
+/*! \brief Animation action for shift a coordination. */
+struct _mb_shift {
+    mb_action_t action;
+
+    co_aix x, y;
+    coord_t *coord;
+
+    mb_timeval_t start_time;
+    co_aix saved_matrix[6];
+    const mb_timeval_t *playing_time;
+};
+
+static void mb_shift_start(mb_action_t *act,
+			   const mb_timeval_t *now,
+			   const mb_timeval_t *playing_time,
+			   redraw_man_t *rdman) {
+    mb_shift_t *shift = (mb_shift_t *)act;
+    coord_t *coord;
+
+    MB_TIMEVAL_CP(&shift->start_time, now);
+    coord = shift->coord;
+    memcpy(&shift->saved_matrix, coord->matrix, sizeof(co_aix[6]));
+    shift->playing_time = playing_time;
+}
+
+static void mb_shift_step(mb_action_t *act, const mb_timeval_t *now,
+			  redraw_man_t *rdman) {
+    mb_shift_t *shift = (mb_shift_t *)act;
+    mb_timeval_t diff;
+    coord_t *coord;
+    float ratio;
+
+    
+    MB_TIMEVAL_CP(&diff, now);
+    MB_TIMEVAL_DIFF(&diff, &shift->start_time);
+    ratio = comp_mb_timeval_ratio(&diff, shift->playing_time);
+
+    coord = shift->coord;
+    coord->matrix[2] = shift->saved_matrix[2] + shift->x * ratio;
+    coord->matrix[5] = shift->saved_matrix[5] + shift->y * ratio;
+
+    rdman_coord_changed(rdman, coord);
+}
+
+static void mb_shift_stop(mb_action_t *act, const mb_timeval_t *now,
+			  redraw_man_t *rdman) {
+    mb_shift_t *shift = (mb_shift_t *)act;
+    coord_t *coord;
+
+    coord = shift->coord;
+    coord->matrix[2] = shift->saved_matrix[2] + shift->x;
+    coord->matrix[5] = shift->saved_matrix[5] + shift->y;
+
+    rdman_coord_changed(rdman, coord);
+}
+
+
+static void mb_shift_free(mb_action_t *act) {
+    free(act);
+}
+
+mb_action_t *mb_shift_new(co_aix x, co_aix y, coord_t *coord,
+			  mb_word_t *word) {
+    mb_shift_t *shift;
+
+    shift = (mb_shift_t *)malloc(sizeof(mb_shift_t));
+    if(shift == NULL)
+	return (mb_action_t *)shift;
+
+    shift->x = x;
+    shift->y = y;
+    shift->coord = coord;
+
+    shift->action.start = mb_shift_start;
+    shift->action.step = mb_shift_step;
+    shift->action.stop = mb_shift_stop;
+    shift->action.free = mb_shift_free;
+
+    mb_word_add_action(word, (mb_action_t *)shift);
+
+    return (mb_action_t *)shift;
+}
+
+