API change: render methods now take a cairo_t (not yet used)

[inkscape.git] / src / helper / png-write.cpp

diff --git a/src/helper/png-write.cpp b/src/helper/png-write.cpp
index 44a977df7ff3180a876057100f31d33a4407e7c0..383e7c56323c2d1f93391be847129d58742deac2 100644 (file)
--- a/src/helper/png-write.cpp
+++ b/src/helper/png-write.cpp
@@ -28,6 +28,7 @@
 #include <sp-item.h>
 #include <sp-root.h>
 #include <sp-defs.h>
+#include "prefs-utils.h"
 
 /* This is an example of how to use libpng to read and write PNG files.
  * The file libpng.txt is much more verbose then this.  If you have not
@@ -41,6 +42,17 @@
  * working PNG reader/writer, see pngtest.c, included in this distribution.
  */
 
+const unsigned int MAX_STRIPE_SIZE = 1024*1024;
+
+struct SPEBP {
+    int width, height, sheight;
+    guchar r, g, b, a;
+    NRArenaItem *root; // the root arena item to show; it is assumed that all unneeded items are hidden
+    guchar *px;
+    unsigned (*status)(float, void *);
+    void *data;
+};
+
 /* write a png file */
 
 typedef struct SPPNGBD {
@@ -76,6 +88,7 @@ sp_png_write_rgba_striped (const gchar *filename, int width, int height, double
                           int (* get_rows) (const guchar **rows, int row, int num_rows, void *data),
                           void *data)
 {
+    struct SPEBP *ebp = (struct SPEBP *) data;
        FILE *fp;
        png_structp png_ptr;
        png_infop info_ptr;
@@ -181,18 +194,18 @@ sp_png_write_rgba_striped (const gchar *filename, int width, int height, double
         * use the first method if you aren't handling interlacing yourself.
         */
 
+       png_bytep* row_pointers = new png_bytep[ebp->sheight];
+
        r = 0;
        while (r < static_cast< png_uint_32 > (height) ) {
-               png_bytep row_pointers[64];
-               int h, n;
-
-               h = MIN (height - r, 64);
-               n = get_rows ((const unsigned char **) row_pointers, r, h, data);
+               int n = get_rows ((const unsigned char **) row_pointers, r, height-r, data);
                if (!n) break;
                png_write_rows (png_ptr, row_pointers, n);
                r += n;
        }
 
+    delete[] row_pointers;
+
        /* You can write optional chunks like tEXt, zTXt, and tIME at the end
         * as well.
         */
@@ -213,17 +226,6 @@ sp_png_write_rgba_striped (const gchar *filename, int width, int height, double
 }
 
 
-
-struct SPEBP {
-    int width, height, sheight;
-    guchar r, g, b, a;
-    NRArenaItem *root; // the root arena item to show; it is assumed that all unneeded items are hidden
-    guchar *px;
-    unsigned (*status)(float, void *);
-    void *data;
-};
-
-
 /**
  *
  */
@@ -240,11 +242,14 @@ sp_export_get_rows(guchar const **rows, int row, int num_rows, void *data)
     num_rows = MIN(num_rows, ebp->height - row);
 
     /* Set area of interest */
+    // bbox is now set to the entire image to prevent discontinuities
+    // in the image when blur is used (the borders may still be a bit
+    // off, but that's less noticeable).
     NRRectL bbox;
     bbox.x0 = 0;
-    bbox.y0 = row;
+    bbox.y0 = 0;//row;
     bbox.x1 = ebp->width;
-    bbox.y1 = row + num_rows;
+    bbox.y1 = ebp->height;//row + num_rows;
     /* Update to renderable state */
     NRGC gc(NULL);
     nr_matrix_set_identity(&gc.transform);
@@ -254,7 +259,7 @@ sp_export_get_rows(guchar const **rows, int row, int num_rows, void *data)
 
     NRPixBlock pb;
     nr_pixblock_setup_extern(&pb, NR_PIXBLOCK_MODE_R8G8B8A8N,
-                             bbox.x0, bbox.y0, bbox.x1, bbox.y1,
+                             bbox.x0, row/*bbox.y0*/, bbox.x1, row + num_rows/*bbox.y1*/,
                              ebp->px, 4 * ebp->width, FALSE, FALSE);
 
     for (int r = 0; r < num_rows; r++) {
@@ -268,7 +273,7 @@ sp_export_get_rows(guchar const **rows, int row, int num_rows, void *data)
     }
 
     /* Render */
-    nr_arena_item_invoke_render(ebp->root, &bbox, &pb, 0);
+    nr_arena_item_invoke_render(NULL, ebp->root, &bbox, &pb, 0);
 
     for (int r = 0; r < num_rows; r++) {
         rows[r] = NR_PIXBLOCK_PX(&pb) + r * pb.rs;
@@ -327,6 +332,10 @@ sp_export_png_file(SPDocument *doc, gchar const *filename,
         return FALSE;
     }
 
+    // export with maximum blur rendering quality
+    int saved_quality = prefs_get_int_attribute ("options.blurquality", "value", 0);
+    prefs_set_int_attribute ("options.blurquality", "value", 2);
+
     sp_document_ensure_up_to_date(doc);
 
     /* Go to document coordinates */
@@ -385,14 +394,14 @@ sp_export_png_file(SPDocument *doc, gchar const *filename,
     ebp.status = status;
     ebp.data   = data;
 
-    if ((width < 256) || ((width * height) < 32768)) {
+    if (4 * width * height < 65536) {
         ebp.px = nr_pixelstore_64K_new(FALSE, 0);
-        ebp.sheight = 65536 / (4 * width);
+        ebp.sheight = height;
         write_status = sp_png_write_rgba_striped(filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
         nr_pixelstore_64K_free(ebp.px);
     } else {
-        ebp.px = g_new(guchar, 4 * 64 * width);
-        ebp.sheight = 64;
+        ebp.sheight = MAX(1,MIN(MAX_STRIPE_SIZE / (4 * width),height));
+        ebp.px = g_new(guchar, 4 * width * ebp.sheight);
         write_status = sp_png_write_rgba_striped(filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
         g_free(ebp.px);
     }
@@ -403,6 +412,10 @@ sp_export_png_file(SPDocument *doc, gchar const *filename,
     /* Free Arena and ArenaItem */
     nr_arena_item_unref(ebp.root);
     nr_object_unref((NRObject *) arena);
+
+    // restore saved blur quality
+    prefs_set_int_attribute ("options.blurquality", "value", saved_quality);
+
     return write_status;
 }