Evas filters: fix blur from rgba to output buffer

When blurring an RGBA buffer to the output buffer,
we don't need to convert the colorspace... but then we'll just
override what was already there.

Introduce a 'dirty' flag set to true whenever a command writes
to an output buffer.

src/lib/evas/filters/evas_filter.c

@@ -892,6 +892,7 @@ evas_filter_command_fill_add(Evas_Filter_Context *ctx, void *draw_context,
    ENFN->context_clip_get(ENDT, draw_context, &cx, &cy, &cw, &ch);
    DRAW_CLIP_SET(cx, cy, cw, ch);
 
+   buf->dirty = EINA_TRUE;
    return cmd->id;
 }
 
@@ -904,7 +905,7 @@ evas_filter_command_blur_add(Evas_Filter_Context *ctx, void *drawctx,
    Evas_Filter_Buffer *in = NULL, *out = NULL, *tmp = NULL, *in_dy = NULL;
    Evas_Filter_Buffer *out_dy = NULL, *out_dx = NULL;
    Evas_Filter_Buffer *copybuf = NULL, *blur_out = NULL;
-   Eina_Bool copy_back = EINA_FALSE, convert = EINA_FALSE;
+   Eina_Bool copy_back = EINA_FALSE, blend = EINA_FALSE;
    int R, G, B, A;
    int ret = 0, id;
 
@@ -929,6 +930,8 @@ evas_filter_command_blur_add(Evas_Filter_Context *ctx, void *drawctx,
         goto fail;
      }
 
+   blend = (out->dirty && !out->transient);
+
    switch (type)
      {
       case EVAS_FILTER_BLUR_GAUSSIAN:
@@ -1008,12 +1011,12 @@ evas_filter_command_blur_add(Evas_Filter_Context *ctx, void *drawctx,
         ERR("Output and input don't have the same format");
         goto fail;
      }
-   else if (in->alpha_only && !out->alpha_only)
+   else if (blend || (in->alpha_only && !out->alpha_only))
      {
-        DBG("Adding extra blending step (Alpha --> RGBA)");
-        blur_out = evas_filter_temporary_buffer_get(ctx, 0, 0, EINA_TRUE);
+        DBG("Adding extra blending step (%s --> RGBA)", in->alpha_only ? "Alpha" : "RGBA");
+        blur_out = evas_filter_temporary_buffer_get(ctx, 0, 0, in->alpha_only);
         if (!blur_out) goto fail;
-        convert = EINA_TRUE;
+        blend = EINA_TRUE;
      }
    else
      blur_out = out;
@@ -1023,7 +1026,7 @@ evas_filter_command_blur_add(Evas_Filter_Context *ctx, void *drawctx,
         tmp = evas_filter_temporary_buffer_get(ctx, 0, 0, in->alpha_only);
         if (!tmp) goto fail;
 
-        if (!convert && (ox || oy))
+        if (!blend && (ox || oy))
           {
              copybuf = evas_filter_temporary_buffer_get(ctx, 0, 0, in->alpha_only);
              if (!copybuf) goto fail;
@@ -1127,13 +1130,16 @@ evas_filter_command_blur_add(Evas_Filter_Context *ctx, void *drawctx,
         ox = oy = 0;
      }
 
-   if (convert)
+   if (blend)
      {
-        DBG("Add convert %d -> %d", blur_out->id, out->id);
+        DBG("Add blend %d (%s) -> %d (%s)",
+            blur_out->id, blur_out->alpha_only ? "Alpha" : "RGBA",
+            out->id, out->alpha_only ? "Alpha" : "RGBA");
         id = evas_filter_command_blend_add(ctx, drawctx, blur_out->id, out->id, ox, oy, EVAS_FILTER_FILL_MODE_NONE);
         if (id < 0) goto fail;
      }
 
+   out->dirty = EINA_TRUE;
    _filter_buffer_unlock_all(ctx);
    return ret;
 
@@ -1192,6 +1198,7 @@ evas_filter_command_blend_add(Evas_Filter_Context *ctx, void *drawctx,
      DBG("Draw clip: %d,%d,%d,%d", cmd->draw.clip.x, cmd->draw.clip.y,
          cmd->draw.clip.w, cmd->draw.clip.h);
 
+   out->dirty = EINA_TRUE;
    return cmd->id;
 }
 
@@ -1202,7 +1209,7 @@ evas_filter_command_grow_add(Evas_Filter_Context *ctx, void *draw_context,
    int blurcmd, threshcmd, blendcmd, tmin = 0, growbuf;
    int diam = abs(radius) * 2 + 1;
    DATA8 curve[256] = {0};
-   Evas_Filter_Buffer *tmp = NULL, *in;
+   Evas_Filter_Buffer *tmp = NULL, *in, *out;
 
    EINA_SAFETY_ON_NULL_RETURN_VAL(ctx, -1);
 
@@ -1246,6 +1253,16 @@ evas_filter_command_grow_add(Evas_Filter_Context *ctx, void *draw_context,
           memset(curve + end, 255, 256 - end);
      }
 
+   out = _filter_buffer_get(ctx, growbuf);
+   if (!out) return -1;
+   out->dirty = EINA_TRUE;
+   if (growbuf != outbuf)
+     {
+        out = _filter_buffer_get(ctx, growbuf);
+        if (!out) return -1;
+        out->dirty = EINA_TRUE;
+     }
+
    threshcmd = evas_filter_command_curve_add(ctx, draw_context, growbuf, growbuf,
                                              curve, EVAS_FILTER_CHANNEL_ALPHA);
    if (threshcmd < 0)
@@ -1312,6 +1329,7 @@ evas_filter_command_curve_add(Evas_Filter_Context *ctx,
    cmd->curve.data = copy;
    cmd->curve.channel = channel;
 
+   out->dirty = EINA_TRUE;
    return cmd->id;
 }
 
@@ -1374,6 +1392,8 @@ evas_filter_command_displacement_map_add(Evas_Filter_Context *ctx,
           }
      }
 
+   out->dirty = EINA_TRUE;
+
 end:
    _filter_buffer_unlock_all(ctx);
    return cmdid;
@@ -1412,6 +1432,7 @@ evas_filter_command_mask_add(Evas_Filter_Context *ctx, void *draw_context,
    DRAW_FILL_SET(fillmode);
 
    cmdid = cmd->id;
+   out->dirty = EINA_TRUE;
 
 end:
    _filter_buffer_unlock_all(ctx);
@@ -1462,6 +1483,8 @@ evas_filter_command_bump_map_add(Evas_Filter_Context *ctx,
    cmd->bump.compensate = !!(flags & EVAS_FILTER_BUMP_COMPENSATE);
    cmdid = cmd->id;
 
+   out->dirty = EINA_TRUE;
+
 end:
    _filter_buffer_unlock_all(ctx);
    return cmdid;
@@ -1501,6 +1524,8 @@ evas_filter_command_transform_add(Evas_Filter_Context *ctx,
    cmd->draw.ox = ox;
    cmd->draw.oy = oy;
 
+   out->dirty = EINA_TRUE;
+
    return cmd->id;
 }
 

src/lib/evas/filters/evas_filter_private.h

@@ -204,6 +204,7 @@ struct _Evas_Filter_Buffer
    Eina_Bool locked : 1;      // internal flag
    Eina_Bool stolen : 1;      // stolen by the client
    Eina_Bool delete_me : 1;   // request delete asap (after released by client)
+   Eina_Bool dirty : 1;       // Marked as dirty as soon as a command writes to it
 };
 
 enum _Evas_Filter_Interpolation_Mode