[Bf-blender-cvs] [96c50ae2bac] soc-2021-vse-strip-thumbnails: VSE strip thumbnail drawing function

[Aditya Y Jeppu]

Commit: 96c50ae2bac91b97b333f812abb558c15da40d9f
Author: Aditya Y Jeppu
Date:   Wed Jun 16 00:18:56 2021 +0530
Branches: soc-2021-vse-strip-thumbnails
https://developer.blender.org/rB96c50ae2bac91b97b333f812abb558c15da40d9f

VSE strip thumbnail drawing function

Thumbnail Drawing Function Improvements T89144

The previous version drew the thumbnails but didn't take into consideration
The visible range where the thumbs should be seen and tried to draw till
end of strip. This version considers only those thumbails which can be seen
and leads to large performance gain. Multiple strips can be used smoothly.
Drawing logic was change to keep same thumbs when strip slide operation was
performed.

Differential Revision: https://developer.blender.org/D11616

===================================================================

M	source/blender/editors/space_sequencer/sequencer_draw.c

===================================================================

diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index a7da8dd85ff..3633cb578d5 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -1089,14 +1089,13 @@ static void draw_seq_strip_thumbnail(View2D *v2d,
                                      SpaceSeq *sseq,
                                      Scene *scene,
                                      Sequence *seq,
-                                     ARegion *region,
                                      float x1,
                                      float y1,
                                      float x2,
+                                     float y2,
                                      float handsize_clamped,
                                      float pixelx,
-                                     float pixely,
-                                     float y_threshold)
+                                     float pixely)
 {
   struct Main *bmain = CTX_data_main(C);
   struct Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
@@ -1104,8 +1103,8 @@ static void draw_seq_strip_thumbnail(View2D *v2d,
   ImBuf *ibuf;
   int rectx, recty;
   double render_size;
-  float y2, strip_x2 = x2;
-  float seq_disp_len;
+  float strip_x2 = x2;
+  bool min_size;
 
   if (sseq->render_size == SEQ_RENDER_SIZE_NONE) {
     return;
@@ -1118,12 +1117,15 @@ static void draw_seq_strip_thumbnail(View2D *v2d,
     render_size = SEQ_rendersize_to_scale_factor(sseq->render_size);
   }
 
-  if (!(y_threshold))
-    return;
-
   rectx = roundf(render_size * scene->r.xsch);
   recty = roundf(render_size * scene->r.ysch);
 
+  /* if thumbs too small ignore */
+  min_size = ((y2 - y1) / pixely) > 40 * U.dpi_fac;
+
+  if (!min_size)
+    return;
+
   SEQ_render_new_render_data(
       bmain, depsgraph, scene, rectx, recty, sseq->render_size, false, &context);
   context.view_id = BKE_scene_multiview_view_id_get(&scene->r, STEREO_LEFT_NAME);
@@ -1139,33 +1141,43 @@ static void draw_seq_strip_thumbnail(View2D *v2d,
   float zoom_x = thumb_w / scene->r.xsch;
   float zoom_y = thumb_h / scene->r.ysch;
 
-  y2 = y1 + thumb_h;
+  y2 = y1 + thumb_h - pixely;
   x1 = x1 + handsize_clamped;
 
-  seq_disp_len = seq->enddisp - seq->startdisp;
-  int frame_offset = thumb_w;
+  int frame_factor = 0;
 
   float upper_thumb_bound = strip_x2 - handsize_clamped;
 
   while (x1 < upper_thumb_bound - 1) {
     x2 = x1 + thumb_w;
 
+    /* Checks to make sure that thumbs are loaded only when in view */
+    if (x1 > v2d->cur.xmax)
+      break;
+
+    if (x2 < v2d->cur.xmin) {
+      x1 = x2;
+      frame_factor++;
+      continue;
+    }
+
     /* clip if full thumbnail cannot be displayed */
     if (x2 >= (upper_thumb_bound - 1)) {
       x2 = (upper_thumb_bound - 1);
-      if (x2 - x1 < 1)
+      if (x2 - x1 < 4)
         break;
     }
 
     /* Get the image */
-    ibuf = SEQ_render_give_ibuf_direct(&context, seq->startdisp + x1 - handsize_clamped, seq);
+    ibuf = SEQ_render_give_ibuf_direct(
+        &context, seq->start + seq->startofs + frame_factor * roundf(thumb_w), seq);
 
     if (ibuf) {
-      ED_draw_imbuf_ctx_clipping(
-          C, ibuf, x1, y1 + pixely * 2, false, x1, y1 + pixely * 2, x2, y2, zoom_x, zoom_y);
+      ED_draw_imbuf_ctx_clipping(C, ibuf, x1, y1, false, x1, y1, x2, y2, zoom_x, zoom_y);
       IMB_freeImBuf(ibuf);
     }
 
+    frame_factor++;
     x1 = x2;
   }
 }
@@ -1270,19 +1282,8 @@ static void draw_seq_strip(const bContext *C,
   }
 
   if (seq->type == SEQ_TYPE_MOVIE) {
-    draw_seq_strip_thumbnail(v2d,
-                             C,
-                             sseq,
-                             scene,
-                             seq,
-                             region,
-                             x1,
-                             y1,
-                             x2,
-                             handsize_clamped,
-                             pixelx,
-                             pixely,
-                             y_threshold);
+    draw_seq_strip_thumbnail(
+        v2d, C, sseq, scene, seq, x1, y1, x2, y2, handsize_clamped, pixelx, pixely);
   }
 
   pos = GPU_vertformat_attr_add(immVertexFormat(), "pos", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);