Add proper scaling to mupdf.renderImage() (#517)

koreader · Sep 24, 2017 · 548077c · 548077c
1 parent 82d9eab
commit 548077c
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diff --git a/ffi/mupdf.lua b/ffi/mupdf.lua
@@ -640,6 +640,15 @@ function mupdf.renderImage(data, size, width, height)
 
     local p_width = M.fz_pixmap_width(context(), pixmap)
     local p_height = M.fz_pixmap_height(context(), pixmap)
+    -- mupdf_new_pixmap_from_image() may not scale image to the
+    -- width and height provided, so check and scale it if needed
+    if width and height and (p_width ~= width or p_height ~= height) then
+        local scaled_pixmap = M.fz_scale_pixmap(context(), pixmap, 0, 0, width, height, nil)
+        M.fz_drop_pixmap(context(), pixmap)
+        pixmap = scaled_pixmap
+        p_width = M.fz_pixmap_width(context(), pixmap)
+        p_height = M.fz_pixmap_height(context(), pixmap)
+    end
     local bbtype
     local ncomp = M.fz_pixmap_components(context(), pixmap)
     if ncomp == 2 then bbtype = BlitBuffer.TYPE_BB8A

diff --git a/ffi/mupdf_h.lua b/ffi/mupdf_h.lua
@@ -290,6 +290,7 @@ fz_pixmap *fz_new_pixmap(fz_context *, fz_colorspace *, int, int);
 fz_pixmap *mupdf_new_pixmap_with_bbox(fz_context *, fz_colorspace *, const fz_irect *);
 fz_pixmap *mupdf_new_pixmap_with_data(fz_context *, fz_colorspace *, int, int, unsigned char *);
 fz_pixmap *mupdf_new_pixmap_with_bbox_and_data(fz_context *, fz_colorspace *, const fz_irect *, unsigned char *);
+fz_pixmap *fz_scale_pixmap(fz_context *, fz_pixmap *, float, float, float, float, fz_irect *);
 void fz_convert_pixmap(fz_context *, fz_pixmap *, fz_pixmap *);
 fz_pixmap *fz_keep_pixmap(fz_context *, fz_pixmap *);
 void fz_drop_pixmap(fz_context *, fz_pixmap *);