Support Banner/Scroll effects with \pos/\move

3 files changed, 43 insertions, 44 deletions

diff --git a/libass/ass_parse.c b/libass/ass_parse.c
index fb57304..cf52b24 100644
--- a/libass/ass_parse.c
+++ b/libass/ass_parse.c
@@ -480,11 +480,11 @@ char *parse_tags(ASS_Renderer *render_priv, char *p, char *end, double pwr,
                 k = ((double) (int32_t) ((uint32_t) t - t1)) / delta_t;
             x = k * (x2 - x1) + x1;
             y = k * (y2 - y1) + y1;
-            if (render_priv->state.evt_type != EVENT_POSITIONED) {
+            if (!(render_priv->state.evt_type & EVENT_POSITIONED)) {
                 render_priv->state.pos_x = x;
                 render_priv->state.pos_y = y;
                 render_priv->state.detect_collisions = 0;
-                render_priv->state.evt_type = EVENT_POSITIONED;
+                render_priv->state.evt_type |= EVENT_POSITIONED;
             }
         } else if (tag("frx")) {
             double val;
@@ -571,11 +571,11 @@ char *parse_tags(ASS_Renderer *render_priv, char *p, char *end, double pwr,
                 v2 = argtod(args[1]);
             } else
                 continue;
-            if (render_priv->state.evt_type == EVENT_POSITIONED) {
+            if (render_priv->state.evt_type & EVENT_POSITIONED) {
                 ass_msg(render_priv->library, MSGL_V, "Subtitle has a new \\pos "
                        "after \\move or \\pos, ignoring");
             } else {
-                render_priv->state.evt_type = EVENT_POSITIONED;
+                render_priv->state.evt_type |= EVENT_POSITIONED;
                 render_priv->state.detect_collisions = 0;
                 render_priv->state.pos_x = v1;
                 render_priv->state.pos_y = v2;
@@ -907,7 +907,7 @@ void apply_transition_effects(ASS_Renderer *render_priv, ASS_Event *event)
             delay = 1;          // ?
         render_priv->state.scroll_shift =
             (render_priv->time - render_priv->state.event->Start) / delay;
-        render_priv->state.evt_type = EVENT_HSCROLL;
+        render_priv->state.evt_type |= EVENT_HSCROLL;
         render_priv->state.wrap_style = 2;
         return;
     }
@@ -946,7 +946,7 @@ void apply_transition_effects(ASS_Renderer *render_priv, ASS_Event *event)
             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.evt_type |= EVENT_VSCROLL;
         render_priv->state.detect_collisions = 0;
     }
 
diff --git a/libass/ass_render.c b/libass/ass_render.c
index 2cec0e4..b405153 100644
--- a/libass/ass_render.c
+++ b/libass/ass_render.c
@@ -2130,7 +2130,7 @@ static void align_lines(ASS_Renderer *render_priv, double max_text_width)
     int justify = render_priv->state.justify;
     double max_width = 0;
 
-    if (render_priv->state.evt_type == EVENT_HSCROLL) {
+    if (render_priv->state.evt_type & EVENT_HSCROLL) {
         justify = halign;
         halign = HALIGN_LEFT;
     }
@@ -2652,13 +2652,23 @@ ass_render_event(ASS_Renderer *render_priv, ASS_Event *event,
     compute_string_bbox(text_info, &bbox);
 
     // determine device coordinates for text
-
-    // x coordinate for everything except positioned events
     double device_x = 0;
-    if (render_priv->state.evt_type == EVENT_NORMAL ||
-        render_priv->state.evt_type == EVENT_VSCROLL) {
-        device_x = x2scr_left(render_priv, MarginL);
-    } else if (render_priv->state.evt_type == EVENT_HSCROLL) {
+    double device_y = 0;
+
+    // handle positioned events first: an event can be both positioned and
+    // scrolling, and the scrolling effect overrides the position on one axis
+    if (render_priv->state.evt_type & EVENT_POSITIONED) {
+        double base_x = 0;
+        double base_y = 0;
+        get_base_point(&bbox, render_priv->state.alignment, &base_x, &base_y);
+        device_x =
+            x2scr_pos(render_priv, render_priv->state.pos_x) - base_x;
+        device_y =
+            y2scr_pos(render_priv, render_priv->state.pos_y) - base_y;
+    }
+
+    // x coordinate
+    if (render_priv->state.evt_type & EVENT_HSCROLL) {
         if (render_priv->state.scroll_direction == SCROLL_RL)
             device_x =
                 x2scr_pos(render_priv,
@@ -2668,12 +2678,24 @@ ass_render_event(ASS_Renderer *render_priv, ASS_Event *event,
             device_x =
                 x2scr_pos(render_priv, render_priv->state.scroll_shift) -
                 (bbox.x_max - bbox.x_min);
+    } else if (!(render_priv->state.evt_type & EVENT_POSITIONED)) {
+        device_x = x2scr_left(render_priv, MarginL);
     }
 
-    // y coordinate for everything except positioned events
-    double device_y = 0;
-    if (render_priv->state.evt_type == EVENT_NORMAL ||
-        render_priv->state.evt_type == EVENT_HSCROLL) {
+    // y coordinate
+    if (render_priv->state.evt_type & EVENT_VSCROLL) {
+        if (render_priv->state.scroll_direction == SCROLL_TB)
+            device_y =
+                y2scr(render_priv,
+                      render_priv->state.clip_y0 +
+                      render_priv->state.scroll_shift) -
+                (bbox.y_max - bbox.y_min);
+        else if (render_priv->state.scroll_direction == SCROLL_BT)
+            device_y =
+                y2scr(render_priv,
+                      render_priv->state.clip_y1 -
+                      render_priv->state.scroll_shift);
+    } else if (!(render_priv->state.evt_type & EVENT_POSITIONED)) {
         if (valign == VALIGN_TOP) {     // toptitle
             device_y =
                 y2scr_top(render_priv,
@@ -2704,29 +2726,6 @@ ass_render_event(ASS_Renderer *render_priv, ASS_Event *event,
                 device_y = scr_y0;
             }
         }
-    } else if (render_priv->state.evt_type == EVENT_VSCROLL) {
-        if (render_priv->state.scroll_direction == SCROLL_TB)
-            device_y =
-                y2scr(render_priv,
-                      render_priv->state.clip_y0 +
-                      render_priv->state.scroll_shift) -
-                (bbox.y_max - bbox.y_min);
-        else if (render_priv->state.scroll_direction == SCROLL_BT)
-            device_y =
-                y2scr(render_priv,
-                      render_priv->state.clip_y1 -
-                      render_priv->state.scroll_shift);
-    }
-
-    // positioned events are totally different
-    if (render_priv->state.evt_type == EVENT_POSITIONED) {
-        double base_x = 0;
-        double base_y = 0;
-        get_base_point(&bbox, render_priv->state.alignment, &base_x, &base_y);
-        device_x =
-            x2scr_pos(render_priv, render_priv->state.pos_x) - base_x;
-        device_y =
-            y2scr_pos(render_priv, render_priv->state.pos_y) - base_y;
     }
 
     // fix clip coordinates
diff --git a/libass/ass_render.h b/libass/ass_render.h
index 93f661a..22d7230 100644
--- a/libass/ass_render.h
+++ b/libass/ass_render.h
@@ -224,10 +224,10 @@ typedef struct {
     double border_x;            // outline width
     double border_y;
     enum {
-        EVENT_NORMAL,           // "normal" top-, sub- or mid- title
-        EVENT_POSITIONED,       // happens after pos(,), margins are ignored
-        EVENT_HSCROLL,          // "Banner" transition effect, text_width is unlimited
-        EVENT_VSCROLL           // "Scroll up", "Scroll down" transition effects
+        EVENT_NORMAL = 0,       // "normal" top-, sub- or mid- title
+        EVENT_POSITIONED = 1,   // happens after \pos or \move, margins are ignored
+        EVENT_HSCROLL = 2,      // "Banner" transition effect, text_width is unlimited
+        EVENT_VSCROLL = 4       // "Scroll up", "Scroll down" transition effects
     } evt_type;
     int border_style;
     uint32_t c[4];              // colors(Primary, Secondary, so on) in RGBA