Cleanup: Remove goto statements from strip rendering functions

Remove goto statement from `seq_render_image_strip()` and `seq_render_movie_strip()`.
`seq_render_image_strip_view()` and `seq_render_movie_strip_view()` is used to render individual views in both monoview and multiview branch.

I have included `seq_can_use_proxy()` for convinience

Reviewed By: sybren

Differential Revision: https://developer.blender.org/D7870

source/blender/blenkernel/intern/sequencer.c

@@ -1180,7 +1180,7 @@ static void seqbase_unique_name(ListBase *seqbasep, SeqUniqueInfo *sui)
   Sequence *seq;
   for (seq = seqbasep->first; seq; seq = seq->next) {
     if ((sui->seq != seq) && STREQ(sui->name_dest, seq->name + 2)) {
-      /* SEQ_NAME_MAXSTR -4 for the number, -1 for \0, - 2 for prefix */
+      /* SEQ_NAME_MAXSTR -4 for the number, -1 for \0, - 2 for r_prefix */
       BLI_snprintf(sui->name_dest,
                    sizeof(sui->name_dest),
                    "%.*s.%03d",
@@ -2247,6 +2247,15 @@ void BKE_sequencer_proxy_set(struct Sequence *seq, bool value)
   }
 }
 
+static bool seq_can_use_proxy(Sequence *seq, IMB_Proxy_Size psize)
+{
+  if (seq->strip->proxy == NULL) {
+    return false;
+  }
+  short size_flags = seq->strip->proxy->build_size_flags;
+  return (seq->flag & SEQ_USE_PROXY) != 0 && psize != IMB_PROXY_NONE && (size_flags & psize) != 0;
+}
+
 /*********************** color balance *************************/
 
 static StripColorBalance calc_cb(StripColorBalance *cb_)
@@ -2985,97 +2994,116 @@ static ImBuf *seq_render_effect_strip_impl(const SeqRenderData *context,
   return out;
 }
 
+/* Render individual view for multiview or single (default view) for monoview. */
+static ImBuf *seq_render_image_strip_view(const SeqRenderData *context,
+                                          Sequence *seq,
+                                          float cfra,
+                                          char *name,
+                                          char *prefix,
+                                          const char *ext,
+                                          int view_id)
+{
+
+  ImBuf *ibuf = NULL;
+
+  int flag = IB_rect | IB_metadata;
+  if (seq->alpha_mode == SEQ_ALPHA_PREMUL) {
+    flag |= IB_alphamode_premul;
+  }
+
+  if (prefix[0] == '\0') {
+    ibuf = IMB_loadiffname(name, flag, seq->strip->colorspace_settings.name);
+  }
+  else {
+    char str[FILE_MAX];
+    seq_multiview_name(context->scene, view_id, prefix, ext, str, FILE_MAX);
+    ibuf = IMB_loadiffname(str, flag, seq->strip->colorspace_settings.name);
+  }
+
+  if (ibuf == NULL) {
+    return NULL;
+  }
+
+  /* We don't need both (speed reasons)! */
+  if (ibuf->rect_float != NULL && ibuf->rect != NULL) {
+    imb_freerectImBuf(ibuf);
+  }
+
+  /* All sequencer color is done in SRGB space, linear gives odd crossfades. */
+  BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, false);
+
+  return ibuf;
+}
+
+static bool seq_image_strip_is_multiview_render(
+    Scene *scene, Sequence *seq, int totfiles, char *name, char *r_prefix, const char *r_ext)
+{
+  if (totfiles > 1) {
+    BKE_scene_multiview_view_prefix_get(scene, name, r_prefix, &r_ext);
+    if (r_prefix[0] == '\0') {
+      return false;
+    }
+  }
+  else {
+    r_prefix[0] = '\0';
+  }
+
+  return (seq->flag & SEQ_USE_VIEWS) != 0 && (scene->r.scemode & R_MULTIVIEW) != 0;
+}
+
 static ImBuf *seq_render_image_strip(const SeqRenderData *context,
                                      Sequence *seq,
                                      float UNUSED(nr),
                                      float cfra)
 {
-  ImBuf *ibuf = NULL;
   char name[FILE_MAX];
-  bool is_multiview = (seq->flag & SEQ_USE_VIEWS) != 0 &&
+  const char *ext = NULL;
-                      (context->scene->r.scemode & R_MULTIVIEW) != 0;
+  char prefix[FILE_MAX];
-  StripElem *s_elem = BKE_sequencer_give_stripelem(seq, cfra);
+  ImBuf *ibuf = NULL;
-  int flag;
+
+  StripElem *s_elem = BKE_sequencer_give_stripelem(seq, cfra);
+  if (s_elem == NULL) {
+    return NULL;
+  }
 
-  if (s_elem) {
   BLI_join_dirfile(name, sizeof(name), seq->strip->dir, s_elem->name);
   BLI_path_abs(name, BKE_main_blendfile_path_from_global());
-  }
 
-  flag = IB_rect | IB_metadata;
-  if (seq->alpha_mode == SEQ_ALPHA_PREMUL) {
-    flag |= IB_alphamode_premul;
-  }
-
-  if (!s_elem) {
-    /* don't do anything */
-  }
-  else if (is_multiview) {
   const int totfiles = seq_num_files(context->scene, seq->views_format, true);
-    int totviews;
+  bool is_multiview_render = seq_image_strip_is_multiview_render(
-    struct ImBuf **ibufs_arr;
+      context->scene, seq, totfiles, name, prefix, ext);
-    char prefix[FILE_MAX];
-    const char *ext = NULL;
 
-    if (totfiles > 1) {
+  if (is_multiview_render) {
-      BKE_scene_multiview_view_prefix_get(context->scene, name, prefix, &ext);
+    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
-      if (prefix[0] == '\0') {
+    ImBuf **ibufs_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
-        goto monoview_image;
-      }
-    }
-    else {
-      prefix[0] = '\0';
-    }
-
-    totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
-    ibufs_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
 
     for (int view_id = 0; view_id < totfiles; view_id++) {
-
+      ibufs_arr[view_id] = seq_render_image_strip_view(
-      if (prefix[0] == '\0') {
+          context, seq, cfra, name, prefix, ext, view_id);
-        ibufs_arr[view_id] = IMB_loadiffname(name, flag, seq->strip->colorspace_settings.name);
-      }
-      else {
-        char str[FILE_MAX];
-        seq_multiview_name(context->scene, view_id, prefix, ext, str, FILE_MAX);
-        ibufs_arr[view_id] = IMB_loadiffname(str, flag, seq->strip->colorspace_settings.name);
     }
 
-      if (ibufs_arr[view_id]) {
+    if (ibufs_arr[0] == NULL) {
-        /* we don't need both (speed reasons)! */
+      return NULL;
-        if (ibufs_arr[view_id]->rect_float && ibufs_arr[view_id]->rect) {
-          imb_freerectImBuf(ibufs_arr[view_id]);
-        }
-      }
     }
 
-    if (seq->views_format == R_IMF_VIEWS_STEREO_3D && ibufs_arr[0]) {
+    if (seq->views_format == R_IMF_VIEWS_STEREO_3D) {
       IMB_ImBufFromStereo3d(seq->stereo3d_format, ibufs_arr[0], &ibufs_arr[0], &ibufs_arr[1]);
     }
 
     for (int view_id = 0; view_id < totviews; view_id++) {
-      if (ibufs_arr[view_id]) {
       SeqRenderData localcontext = *context;
       localcontext.view_id = view_id;
 
-        /* all sequencer color is done in SRGB space, linear gives odd crossfades */
-        BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibufs_arr[view_id], false);
-
       if (view_id != context->view_id) {
         ibufs_arr[view_id] = seq_render_preprocess_ibuf(
             &localcontext, seq, ibufs_arr[view_id], cfra, clock(), true, false, false);
       }
     }
-    }
 
-    /* return the original requested ImBuf */
+    /* Return the original requested ImBuf. */
     ibuf = ibufs_arr[context->view_id];
-    if (ibuf) {
-      s_elem->orig_width = ibufs_arr[0]->x;
-      s_elem->orig_height = ibufs_arr[0]->y;
-    }
 
-    /* "remove" the others (decrease their refcount) */
+    /* Remove the others (decrease their refcount). */
     for (int view_id = 0; view_id < totviews; view_id++) {
       if (ibufs_arr[view_id] != ibuf) {
         IMB_freeImBuf(ibufs_arr[view_id]);
@@ -3085,19 +3113,51 @@ static ImBuf *seq_render_image_strip(const SeqRenderData *context,
     MEM_freeN(ibufs_arr);
   }
   else {
-  monoview_image:
+    ibuf = seq_render_image_strip_view(context, seq, cfra, name, prefix, ext, context->view_id);
-    if ((ibuf = IMB_loadiffname(name, flag, seq->strip->colorspace_settings.name))) {
-      /* we don't need both (speed reasons)! */
-      if (ibuf->rect_float && ibuf->rect) {
-        imb_freerectImBuf(ibuf);
   }
 
-      /* all sequencer color is done in SRGB space, linear gives odd crossfades */
+  if (ibuf == NULL) {
-      BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, false);
+    return NULL;
+  }
 
   s_elem->orig_width = ibuf->x;
   s_elem->orig_height = ibuf->y;
+
+  return ibuf;
+}
+
+/* Render individual view for multiview or single (default view) for monoview. */
+static ImBuf *seq_render_movie_strip_view(
+    const SeqRenderData *context, Sequence *seq, float nr, float cfra, StripAnim *sanim)
+{
+  ImBuf *ibuf = NULL;
+  IMB_Proxy_Size psize = seq_rendersize_to_proxysize(context->preview_render_size);
+
+  IMB_anim_set_preseek(sanim->anim, seq->anim_preseek);
+
+  if (seq_can_use_proxy(seq, psize)) {
+    ibuf = IMB_anim_absolute(sanim->anim,
+                             nr + seq->anim_startofs,
+                             seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
+                             psize);
   }
+
+  /* Fetching for requested proxy size failed, try fetching the original instead. */
+  if (ibuf == NULL) {
+    ibuf = IMB_anim_absolute(sanim->anim,
+                             nr + seq->anim_startofs,
+                             seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
+                             IMB_PROXY_NONE);
+  }
+  if (ibuf == NULL) {
+    return NULL;
+  }
+
+  BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, false);
+
+  /* We don't need both (speed reasons)! */
+  if (ibuf->rect_float != NULL && ibuf->rect != NULL) {
+    imb_freerectImBuf(ibuf);
   }
 
   return ibuf;
@@ -3108,93 +3168,52 @@ static ImBuf *seq_render_movie_strip(const SeqRenderData *context,
                                      float nr,
                                      float cfra)
 {
-  ImBuf *ibuf = NULL;
+  /* Load all the videos. */
-  StripAnim *sanim;
-
-  bool is_multiview = (seq->flag & SEQ_USE_VIEWS) != 0 &&
-                      (context->scene->r.scemode & R_MULTIVIEW) != 0;
-
-  IMB_Proxy_Size psize = seq_rendersize_to_proxysize(context->preview_render_size);
-
-  if ((seq->flag & SEQ_USE_PROXY) == 0) {
-    psize = IMB_PROXY_NONE;
-  }
-  /* load all the videos */
   seq_open_anim_file(context->scene, seq, false);
 
-  if (is_multiview) {
+  ImBuf *ibuf = NULL;
-    ImBuf **ibuf_arr;
+  StripAnim *sanim = seq->anims.first;
   const int totfiles = seq_num_files(context->scene, seq->views_format, true);
-    int totviews;
+  bool is_multiview_render = (seq->flag & SEQ_USE_VIEWS) != 0 &&
-    int ibuf_view_id;
+                             (context->scene->r.scemode & R_MULTIVIEW) != 0 &&
+                             BLI_listbase_count_at_most(&seq->anims, totfiles + 1) == totfiles;
 
-    if (totfiles != BLI_listbase_count_at_most(&seq->anims, totfiles + 1)) {
+  if (is_multiview_render) {
-      goto monoview_movie;
+    ImBuf **ibuf_arr;
-    }
+    int totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
-
-    totviews = BKE_scene_multiview_num_views_get(&context->scene->r);
     ibuf_arr = MEM_callocN(sizeof(ImBuf *) * totviews, "Sequence Image Views Imbufs");
+    int ibuf_view_id;
 
     for (ibuf_view_id = 0, sanim = seq->anims.first; sanim; sanim = sanim->next, ibuf_view_id++) {
       if (sanim->anim) {
-        IMB_anim_set_preseek(sanim->anim, seq->anim_preseek);
+        ibuf_arr[ibuf_view_id] = seq_render_movie_strip_view(context, seq, nr, cfra, sanim);
-
-        ibuf_arr[ibuf_view_id] = IMB_anim_absolute(sanim->anim,
-                                                   nr + seq->anim_startofs,
-                                                   seq->strip->proxy ? seq->strip->proxy->tc :
-                                                                       IMB_TC_RECORD_RUN,
-                                                   psize);
-
-        /* fetching for requested proxy size failed, try fetching the original instead */
-        if (!ibuf_arr[ibuf_view_id] && psize != IMB_PROXY_NONE) {
-          ibuf_arr[ibuf_view_id] = IMB_anim_absolute(sanim->anim,
-                                                     nr + seq->anim_startofs,
-                                                     seq->strip->proxy ? seq->strip->proxy->tc :
-                                                                         IMB_TC_RECORD_RUN,
-                                                     IMB_PROXY_NONE);
-        }
-        if (ibuf_arr[ibuf_view_id]) {
-          /* we don't need both (speed reasons)! */
-          if (ibuf_arr[ibuf_view_id]->rect_float && ibuf_arr[ibuf_view_id]->rect) {
-            imb_freerectImBuf(ibuf_arr[ibuf_view_id]);
-          }
-        }
       }
     }
 
     if (seq->views_format == R_IMF_VIEWS_STEREO_3D) {
-      if (ibuf_arr[0]) {
+      if (ibuf_arr[0] == NULL) {
-        IMB_ImBufFromStereo3d(seq->stereo3d_format, ibuf_arr[0], &ibuf_arr[0], &ibuf_arr[1]);
+        /* Probably proxy hasn't been created yet. */
-      }
-      else {
-        /* probably proxy hasn't been created yet */
         MEM_freeN(ibuf_arr);
         return NULL;
       }
+
+      IMB_ImBufFromStereo3d(seq->stereo3d_format, ibuf_arr[0], &ibuf_arr[0], &ibuf_arr[1]);
     }
 
     for (int view_id = 0; view_id < totviews; view_id++) {
       SeqRenderData localcontext = *context;
       localcontext.view_id = view_id;
 
-      if (ibuf_arr[view_id]) {
-        /* all sequencer color is done in SRGB space, linear gives odd crossfades */
-        BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf_arr[view_id], false);
-      }
       if (view_id != context->view_id) {
         ibuf_arr[view_id] = seq_render_preprocess_ibuf(
             &localcontext, seq, ibuf_arr[view_id], cfra, clock(), true, false, false);
       }
     }
 
-    /* return the original requested ImBuf */
+    /* Return the original requested ImBuf. */
     ibuf = ibuf_arr[context->view_id];
-    if (ibuf) {
-      seq->strip->stripdata->orig_width = ibuf->x;
-      seq->strip->stripdata->orig_height = ibuf->y;
-    }
 
-    /* "remove" the others (decrease their refcount) */
+    /* Remove the others (decrease their refcount). */
     for (int view_id = 0; view_id < totviews; view_id++) {
       if (ibuf_arr[view_id] != ibuf) {
         IMB_freeImBuf(ibuf_arr[view_id]);
@@ -3204,36 +3223,16 @@ static ImBuf *seq_render_movie_strip(const SeqRenderData *context,
     MEM_freeN(ibuf_arr);
   }
   else {
-  monoview_movie:
+    ibuf = seq_render_movie_strip_view(context, seq, nr, cfra, sanim);
-    sanim = seq->anims.first;
-    if (sanim && sanim->anim) {
-      IMB_anim_set_preseek(sanim->anim, seq->anim_preseek);
-
-      ibuf = IMB_anim_absolute(sanim->anim,
-                               nr + seq->anim_startofs,
-                               seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
-                               psize);
-
-      /* fetching for requested proxy size failed, try fetching the original instead */
-      if (!ibuf && psize != IMB_PROXY_NONE) {
-        ibuf = IMB_anim_absolute(sanim->anim,
-                                 nr + seq->anim_startofs,
-                                 seq->strip->proxy ? seq->strip->proxy->tc : IMB_TC_RECORD_RUN,
-                                 IMB_PROXY_NONE);
   }
-      if (ibuf) {
-        BKE_sequencer_imbuf_to_sequencer_space(context->scene, ibuf, false);
 
-        /* we don't need both (speed reasons)! */
+  if (ibuf == NULL) {
-        if (ibuf->rect_float && ibuf->rect) {
+    return NULL;
-          imb_freerectImBuf(ibuf);
   }
 
   seq->strip->stripdata->orig_width = ibuf->x;
   seq->strip->stripdata->orig_height = ibuf->y;
-      }
+
-    }
-  }
   return ibuf;
 }
 
@@ -5016,7 +5015,7 @@ int BKE_sequence_swap(Sequence *seq_a, Sequence *seq_b, const char **error_str)
   return 1;
 }
 
-/* prefix + [" + escaped_name + "] + \0 */
+/* r_prefix + [" + escaped_name + "] + \0 */
 #define SEQ_RNAPATH_MAXSTR ((30 + 2 + (SEQ_NAME_MAXSTR * 2) + 2) + 1)
 
 static size_t sequencer_rna_path_prefix(char str[SEQ_RNAPATH_MAXSTR], const char *name)