Refactor: effect parsing should be in ass_parse.c

Move the function apply_transition_effects, which parses event-global
effects and adjusts a few state variables, into ass_parse.c.

1 files changed, 75 insertions, 0 deletions

diff --git a/libass/ass_parse.c b/libass/ass_parse.c
index 0f3b441..535e16f 100644
--- a/libass/ass_parse.c
+++ b/libass/ass_parse.c
@@ -802,6 +802,81 @@ static char *parse_tag(ASS_Renderer *render_priv, char *p, double pwr)
     return p;
 }
 
+void apply_transition_effects(ASS_Renderer *render_priv, ASS_Event *event)
+{
+    int v[4];
+    int cnt;
+    char *p = event->Effect;
+
+    if (!p || !*p)
+        return;
+
+    cnt = 0;
+    while (cnt < 4 && (p = strchr(p, ';'))) {
+        v[cnt++] = atoi(++p);
+    }
+
+    if (strncmp(event->Effect, "Banner;", 7) == 0) {
+        int delay;
+        if (cnt < 1) {
+            ass_msg(render_priv->library, MSGL_V,
+                    "Error parsing effect: '%s'", event->Effect);
+            return;
+        }
+        if (cnt >= 2 && v[1] == 0)      // right-to-left
+            render_priv->state.scroll_direction = SCROLL_RL;
+        else                    // left-to-right
+            render_priv->state.scroll_direction = SCROLL_LR;
+
+        delay = v[0];
+        if (delay == 0)
+            delay = 1;          // ?
+        render_priv->state.scroll_shift =
+            (render_priv->time - render_priv->state.event->Start) / delay;
+        render_priv->state.evt_type = EVENT_HSCROLL;
+        return;
+    }
+
+    if (strncmp(event->Effect, "Scroll up;", 10) == 0) {
+        render_priv->state.scroll_direction = SCROLL_BT;
+    } else if (strncmp(event->Effect, "Scroll down;", 12) == 0) {
+        render_priv->state.scroll_direction = SCROLL_TB;
+    } else {
+        ass_msg(render_priv->library, MSGL_V,
+                "Unknown transition effect: '%s'", event->Effect);
+        return;
+    }
+    // parse scroll up/down parameters
+    {
+        int delay;
+        int y0, y1;
+        if (cnt < 3) {
+            ass_msg(render_priv->library, MSGL_V,
+                    "Error parsing effect: '%s'", event->Effect);
+            return;
+        }
+        delay = v[2];
+        if (delay == 0)
+            delay = 1;          // ?
+        render_priv->state.scroll_shift =
+            (render_priv->time - render_priv->state.event->Start) / delay;
+        if (v[0] < v[1]) {
+            y0 = v[0];
+            y1 = v[1];
+        } else {
+            y0 = v[1];
+            y1 = v[0];
+        }
+        if (y1 == 0)
+            y1 = render_priv->track->PlayResY;  // y0=y1=0 means fullscreen scrolling
+        render_priv->state.clip_y0 = y0;
+        render_priv->state.clip_y1 = y1;
+        render_priv->state.evt_type = EVENT_VSCROLL;
+        render_priv->state.detect_collisions = 0;
+    }
+
+}
+
 /**
  * \brief Get next ucs4 char from string, parsing and executing style overrides
  * \param str string pointer