Filter effects: support for SourceAlpha and BackgroundAlpha

diff --git a/src/display/Makefile_insert b/src/display/Makefile_insert
index a4d7470017c9c99bf7214d2405dc4b821cd1ccf0..462da04c58f05d31a05fc7960a373e6fbbd1a697 100644 (file)
--- a/src/display/Makefile_insert
+++ b/src/display/Makefile_insert
@@ -75,6 +75,8 @@ display_libspdisplay_a_SOURCES = \
        display/nr-filter-offset.h      \
        display/nr-filter-slot.cpp      \
        display/nr-filter-slot.h        \
+       display/nr-filter-getalpha.cpp  \
+       display/nr-filter-getalpha.h    \
        display/nr-filter-types.h       \
        display/pixblock-scaler.cpp     \
        display/pixblock-scaler.h       \

diff --git a/src/display/nr-filter-getalpha.cpp b/src/display/nr-filter-getalpha.cpp
new file mode 100644 (file)
index 0000000..1aba770
--- /dev/null
+++ b/src/display/nr-filter-getalpha.cpp
@@ -0,0 +1,49 @@
+/*
+ * Functions for extracting alpha channel from NRPixBlocks.
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 Niko Kiirala
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "display/nr-filter-getalpha.h"
+#include "libnr/nr-blit.h"
+#include "libnr/nr-pixblock.h"
+
+namespace NR {
+
+NRPixBlock *filter_get_alpha(NRPixBlock *src)
+{
+    NRPixBlock *dst = new NRPixBlock;
+    nr_pixblock_setup_fast(dst, NR_PIXBLOCK_MODE_R8G8B8A8P,
+                           src->area.x0, src->area.y0,
+                           src->area.x1, src->area.y1, false);
+    nr_blit_pixblock_pixblock(dst, src);
+
+    unsigned char *data = NR_PIXBLOCK_PX(dst);
+    int end = dst->rs * (dst->area.y1 - dst->area.y0);
+    for (int i = 0 ; i < end ; i += 4) {
+        data[i + 0] = 0;
+        data[i + 1] = 0;
+        data[i + 2] = 0;
+    }
+    dst->empty = false;
+
+    return dst;
+}
+
+} // namespace NR
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :

diff --git a/src/display/nr-filter-getalpha.h b/src/display/nr-filter-getalpha.h
new file mode 100644 (file)
index 0000000..cfbca0b
--- /dev/null
+++ b/src/display/nr-filter-getalpha.h
@@ -0,0 +1,33 @@
+#ifndef __NR_FILTER_GETALPHA_H__
+#define __NR_FILTER_GETALPHA_H__
+
+/*
+ * Functions for extracting alpha channel from NRPixBlocks.
+ *
+ * Author:
+ *   Niko Kiirala <niko@kiirala.com>
+ *
+ * Copyright (C) 2007 Niko Kiirala
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ */
+
+#include "libnr/nr-pixblock.h"
+
+namespace NR {
+
+NRPixBlock *filter_get_alpha(NRPixBlock *src);
+
+}
+
+#endif /* __NR_FILTER_GETALPHA_H__ */
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :

diff --git a/src/display/nr-filter-slot.cpp b/src/display/nr-filter-slot.cpp
index 32fc00f9950ddecbd326164fc94cba9fdcec6d85..3cdc20ede9cd554f4a4a66cfc62baaf56e052815 100644 (file)
--- a/src/display/nr-filter-slot.cpp
+++ b/src/display/nr-filter-slot.cpp
@@ -18,6 +18,7 @@
 #include "display/nr-arena-item.h"
 #include "display/nr-filter-types.h"
 #include "display/nr-filter-slot.h"
+#include "display/nr-filter-getalpha.h"
 #include "libnr/nr-pixblock.h"
 #include "libnr/nr-blit.h"
 
@@ -66,22 +67,12 @@ NRPixBlock *FilterSlot::get(int slot_nr)
             || slot_nr == NR_FILTER_STROKEPAINT))
     {
         /* If needed, fetch background */
-        if (slot_nr == NR_FILTER_BACKGROUNDIMAGE
-            || slot_nr == NR_FILTER_BACKGROUNDALPHA)
-        {
+        if (slot_nr == NR_FILTER_BACKGROUNDIMAGE) {
             NRPixBlock *pb;
             pb = nr_arena_item_get_background(_arena_item);
             if (pb) {
-                NRPixBlock *bg = new NRPixBlock;
-                nr_pixblock_setup_fast(bg, pb->mode,
-                                       pb->area.x0, pb->area.y0,
-                                       pb->area.x1, pb->area.y1, true);
-                bool empty = pb->empty;
                 pb->empty = false;
-                nr_blit_pixblock_pixblock(bg, pb);
-                pb->empty = empty;
-                bg->empty = false;
-                this->set(NR_FILTER_BACKGROUNDIMAGE, bg);
+                this->set(NR_FILTER_BACKGROUNDIMAGE, pb);
             } else {
                 NRPixBlock *source = this->get(NR_FILTER_SOURCEGRAPHIC);
                 pb = new NRPixBlock();
@@ -97,19 +88,19 @@ NRPixBlock *FilterSlot::get(int slot_nr)
                 pb->empty = FALSE;
                 this->set(NR_FILTER_BACKGROUNDIMAGE, pb);
             }
-        }
-        /* If only a alpha channel is needed, strip it from full image */
-        if (slot_nr == NR_FILTER_SOURCEALPHA) {
-            // TODO
-        }
-        if (slot_nr == NR_FILTER_BACKGROUNDALPHA) {
+        } else if (slot_nr == NR_FILTER_SOURCEALPHA) {
+            /* If only a alpha channel is needed, strip it from full image */
+            NRPixBlock *src = get(NR_FILTER_SOURCEGRAPHIC);
+            NRPixBlock *sa = filter_get_alpha(src);
+            set(NR_FILTER_SOURCEALPHA, sa);
+        } else if (slot_nr == NR_FILTER_BACKGROUNDALPHA) {
+            NRPixBlock *src = get(NR_FILTER_BACKGROUNDIMAGE);
+            NRPixBlock *ba = filter_get_alpha(src);
+            set(NR_FILTER_BACKGROUNDALPHA, ba);
+        } else if (slot_nr == NR_FILTER_FILLPAINT) {
+            /* When a paint is needed, fetch it from arena item */
             // TODO
-        }
-        /* When a paint is needed, fetch it from arena item */
-        if (slot_nr == NR_FILTER_FILLPAINT) {
-            // TODO
-        }
-        if (slot_nr == NR_FILTER_STROKEPAINT) {
+        } else if (slot_nr == NR_FILTER_STROKEPAINT) {
             // TODO
         }
     }
@@ -137,8 +128,8 @@ int FilterSlot::get_slot_count()
     int seek = _slot_count;
     do {
         seek--;
-    } while (_slot[seek] == NULL);
-    
+    } while (!_slot[seek] && _slot_number[seek] == NR_FILTER_SLOT_NOT_SET);
+
     return seek + 1;
 }
 
@@ -170,7 +161,7 @@ int FilterSlot::_get_index(int slot_nr)
         int seek = _slot_count;
         do {
             seek--;
-        } while (_slot[seek] == NULL && seek > 0);
+        } while (_slot_number[seek] == NR_FILTER_SLOT_NOT_SET && seek >= 0);
         /* If there is no space for more slots, create more space */
         if (seek == _slot_count - 1) {
             NRPixBlock **new_slot = new NRPixBlock*[_slot_count * 2];