Evas filters: Clear buffers after allocation

malloc() and mmap() don't return empty buffers, so blending on top
will present tons of artifacts.
Visible mostly on very small buffers as they are malloc()'ed from
previously used memory segments.

diff --git a/src/lib/evas/filters/evas_filter.c b/src/lib/evas/filters/evas_filter.c
index 1b377a7..8b5b258 100644 (file)
--- a/src/lib/evas/filters/evas_filter.c
+++ b/src/lib/evas/filters/evas_filter.c
@@ -268,11 +268,30 @@ _buffer_new(Evas_Filter_Context *ctx, int w, int h, Eina_Bool alpha_only)
    return fb;
 }
 
-Eina_Bool
-evas_filter_buffer_alloc(Evas_Filter_Buffer *fb, int w, int h)
+static RGBA_Image *
+_rgba_image_alloc(Evas_Filter_Buffer const *fb)
 {
    Evas_Colorspace cspace;
+   RGBA_Image *image;
+   size_t sz;
+
+   cspace = fb->alpha_only ? EVAS_COLORSPACE_GRY8 : EVAS_COLORSPACE_ARGB8888;
+   image = fb->ENFN->image_new_from_copied_data
+     (fb->ENDT, fb->w, fb->h, NULL, EINA_TRUE, cspace);
+   if (!image) return EINA_FALSE;
 
+   if (fb->alpha_only)
+     sz = image->cache_entry.w * image->cache_entry.h * sizeof(DATA8);
+   else
+     sz = image->cache_entry.w * image->cache_entry.h * sizeof(DATA32);
+   memset(image->image.data, 0, sz);
+
+   return image;
+}
+
+Eina_Bool
+evas_filter_buffer_alloc(Evas_Filter_Buffer *fb, int w, int h)
+{
    if (!fb) return EINA_FALSE;
    if (fb->backing)
      {
@@ -301,14 +320,9 @@ evas_filter_buffer_alloc(Evas_Filter_Buffer *fb, int w, int h)
    fb->w = w;
    fb->h = h;
 
-   cspace = fb->alpha_only ? EVAS_COLORSPACE_GRY8 : EVAS_COLORSPACE_ARGB8888;
-
-   fb->backing = fb->ENFN->image_new_from_copied_data
-     (fb->ENDT, fb->w, fb->h, NULL, EINA_TRUE, cspace);
-   if (!fb->backing) return EINA_FALSE;
-
-   fb->allocated = EINA_TRUE;
-   return EINA_TRUE;
+   fb->backing = _rgba_image_alloc(fb);
+   fb->allocated = (fb->backing != NULL);
+   return fb->allocated;
 }
 
 int
@@ -331,8 +345,6 @@ evas_filter_buffer_data_set(Evas_Filter_Context *ctx, int bufid, void *data,
                             int w, int h, Eina_Bool alpha_only)
 {
    Evas_Filter_Buffer *fb;
-   Evas_Colorspace cs;
-   void *image;
 
    EINA_SAFETY_ON_NULL_RETURN_VAL(ctx, EINA_FALSE);
 
@@ -355,15 +367,9 @@ evas_filter_buffer_data_set(Evas_Filter_Context *ctx, int bufid, void *data,
    fb->w = w;
    fb->h = h;
 
-   cs = alpha_only ? EVAS_COLORSPACE_GRY8 : EVAS_COLORSPACE_ARGB8888;
-   if (data)
-     image = ENFN->image_new_from_data(ENDT, w, h, data, EINA_TRUE, cs);
-   else
-     image = ENFN->image_new_from_copied_data(ENDT, w, h, NULL, EINA_TRUE, cs);
-   if (!image) return EINA_FALSE;
-
-   fb->backing = image;
-   return EINA_TRUE;
+   fb->backing = _rgba_image_alloc(fb);
+   fb->allocated = (fb->backing != NULL);
+   return fb->allocated;
 }
 
 int