[patch] Patch 3

0003-Apply-subpixel-rendering-in-Cairo-Backend.patch (text/plain), 9.59 KB, created by Miroslaw Mieszczak on 2023-12-20 07:36:44 UTC

diff -ur poppler-23.09.0/glib/demo/render.c poppler-23.09.0.patched/glib/demo/render.c
--- poppler-23.09.0/glib/demo/render.c	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/glib/demo/render.c	2023-11-30 18:01:41.000547101 +0100
@@ -79,12 +79,15 @@
 static void pgd_render_start(GtkButton *button, PgdRenderDemo *demo)
 {
     PopplerPage *page;
+    gboolean     subpixel_rendering;
     gdouble page_width, page_height;
     gdouble width, height;
     gint x, y;
     gchar *str;
     GTimer *timer;
     cairo_t *cr;
+    cairo_font_options_t *fo;
+
 
     page = poppler_document_get_page(demo->doc, demo->page);
     if (!page) {
@@ -114,6 +117,21 @@
     demo->surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
     cr = cairo_create(demo->surface);
 
+    fo = cairo_font_options_create ();
+    cairo_get_font_options (cr, fo);
+
+    subpixel_rendering = poppler_page_support_subpixel_rendering (page);
+    printf("subpixel_rendering %d\n", subpixel_rendering);
+    if (subpixel_rendering) {
+        cairo_set_source_rgb (cr, 1., 1., 1.);
+        cairo_paint (cr);
+        cairo_font_options_set_antialias (fo, CAIRO_ANTIALIAS_SUBPIXEL);
+        cairo_font_options_set_subpixel_order (fo, CAIRO_SUBPIXEL_ORDER_RGB);
+    }
+
+    cairo_set_font_options (cr, fo);
+    cairo_font_options_destroy (fo);
+
     cairo_save(cr);
     switch (demo->rotate) {
     case 90:
@@ -144,9 +162,11 @@
     }
     cairo_restore(cr);
 
-    cairo_set_operator(cr, CAIRO_OPERATOR_DEST_OVER);
-    cairo_set_source_rgb(cr, 1., 1., 1.);
-    cairo_paint(cr);
+    if (!subpixel_rendering) {
+        cairo_set_operator(cr, CAIRO_OPERATOR_DEST_OVER);
+        cairo_set_source_rgb(cr, 1., 1., 1.);
+        cairo_paint(cr);
+    }
 
     g_timer_stop(timer);
 
diff -ur poppler-23.09.0/glib/poppler-page.cc poppler-23.09.0.patched/glib/poppler-page.cc
--- poppler-23.09.0/glib/poppler-page.cc	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/glib/poppler-page.cc	2023-11-30 18:07:07.875433617 +0100
@@ -2572,3 +2572,13 @@
 
     return g_list_reverse(attributes);
 }
+
+gboolean
+poppler_page_support_subpixel_rendering (PopplerPage        *page)
+{
+  CairoOutputDev *output_dev;
+  g_return_val_if_fail (POPPLER_IS_PAGE (page), FALSE);
+
+  output_dev = page->document->output_dev;
+  return page->page->supportSubpixelRendering(output_dev);
+}
diff -ur poppler-23.09.0/glib/poppler-page.h poppler-23.09.0.patched/glib/poppler-page.h
--- poppler-23.09.0/glib/poppler-page.h	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/glib/poppler-page.h	2023-11-30 18:09:23.142489921 +0100
@@ -112,6 +112,8 @@
 POPPLER_PUBLIC
 GList *poppler_page_get_text_attributes_for_area(PopplerPage *page, PopplerRectangle *area);
 
+gboolean         poppler_page_support_subpixel_rendering (PopplerPage        *page);
+
 /* A rectangle on a page, with coordinates in PDF points. */
 #define POPPLER_TYPE_RECTANGLE (poppler_rectangle_get_type())
 /**
diff -ur poppler-23.09.0/poppler/CairoFontEngine.cc poppler-23.09.0.patched/poppler/CairoFontEngine.cc
--- poppler-23.09.0/poppler/CairoFontEngine.cc	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/CairoFontEngine.cc	2023-11-30 18:20:21.686158628 +0100
@@ -114,7 +114,7 @@
                 cairo_matrix_t m;
                 cairo_matrix_init_identity(&m);
                 cairo_font_options_t *options = cairo_font_options_create();
-                cairo_font_options_set_hint_style(options, CAIRO_HINT_STYLE_NONE);
+	cairo_font_options_set_hint_style(options, CAIRO_HINT_STYLE_SLIGHT);
                 cairo_font_options_set_hint_metrics(options, CAIRO_HINT_METRICS_OFF);
                 cairo_scaled_font_t *scaled_font = cairo_scaled_font_create(cairo_font_face, &m, &m, options);
 
@@ -186,7 +186,7 @@
         }
     }
 
-    font_face.cairo_font_face = cairo_ft_font_face_create_for_ft_face(resource->face, FT_LOAD_NO_HINTING | FT_LOAD_NO_BITMAP);
+    font_face.cairo_font_face = cairo_ft_font_face_create_for_ft_face(resource->face, FT_LOAD_TARGET_LIGHT | FT_LOAD_NO_BITMAP);
     if (cairo_font_face_set_user_data(font_face.cairo_font_face, &ft_cairo_key, resource, _ft_done_face)) {
         cairo_font_face_destroy(font_face.cairo_font_face);
         _ft_done_face(resource);
diff -ur poppler-23.09.0/poppler/CairoOutputDev.cc poppler-23.09.0.patched/poppler/CairoOutputDev.cc
--- poppler-23.09.0/poppler/CairoOutputDev.cc	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/CairoOutputDev.cc	2023-11-30 18:16:28.287237879 +0100
@@ -223,6 +223,13 @@
     }
     if (c != nullptr) {
         cairo = cairo_reference(c);
+        {
+          cairo_font_options_t *options = cairo_font_options_create ();
+          cairo_get_font_options (cairo, options);
+          cairo_font_options_set_antialias (options, CAIRO_ANTIALIAS_SUBPIXEL);
+          cairo_set_font_options (cairo, options);
+          cairo_font_options_destroy (options);
+        }
         /* save the initial matrix so that we can use it for type3 fonts. */
         // XXX: is this sufficient? could we miss changes to the matrix somehow?
         cairo_get_matrix(cairo, &orig_matrix);
@@ -1519,6 +1526,7 @@
 void CairoOutputDev::endString(GfxState *state)
 {
     int render;
+  GfxFontType fontType;
 
     if (!currentFont) {
         return;
@@ -1544,6 +1552,18 @@
         render = 0;
     }
 
+  fontType = state->getFont()->getType();
+  // Do not enable subpixel rendering for type3 font
+  // For some reason it does not work
+  if (fontType == fontType3) {
+      cairo_save(cairo);
+      cairo_font_options_t *fo;
+      fo = cairo_font_options_create ();
+      cairo_get_font_options (cairo, fo);
+      cairo_font_options_set_antialias (fo, CAIRO_ANTIALIAS_DEFAULT);
+      cairo_set_font_options (cairo, fo);
+  }
+
     if (!(render & 1)) {
         LOG(printf("fill string\n"));
         cairo_set_source(cairo, fill_pattern);
@@ -1596,6 +1616,10 @@
     }
 
 finish:
+    // pair with the previous cairo_save to disable subpixel rendering for type3 fonts
+    if (fontType == fontType3) {
+        cairo_restore(cairo);
+    }
     gfree(glyphs);
     glyphs = nullptr;
     if (use_show_text_glyphs) {
diff -ur poppler-23.09.0/poppler/Gfx.cc poppler-23.09.0.patched/poppler/Gfx.cc
--- poppler-23.09.0/poppler/Gfx.cc	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/Gfx.cc	2023-11-30 18:22:28.913389896 +0100
@@ -4603,6 +4603,47 @@
     error(errSyntaxError, getPos(), "Bad image parameters");
 }
 
+bool Gfx::checkNormalBlendModeOnly(Object *str) {
+  printf("check blender mode start\n");
+  Object args[maxArgs];
+  int numArgs;
+  bool onlyNormalBlendMode;
+  Parser myParser(xref, str, false);
+
+  numArgs = 0;
+  onlyNormalBlendMode = true;
+
+  Object obj = myParser.getObj();
+  while (!obj.isEOF()) {
+    if (obj.isCmd()) {
+      const char* cmd = obj.getCmd();
+
+      if (strcmp(cmd, "gs") == 0) {
+        GfxBlendMode mode;
+        Object obj1 = res->lookupGState(args[0].getName());
+        if (!obj1.isNull()) {
+          Object obj2 = obj1.dictLookup("BM");
+          if (!obj2.isNull()) {
+            if (state->parseBlendMode(&obj2, &mode)) {
+              printf("check blend mode: %d\n", mode);
+              onlyNormalBlendMode &= (mode == gfxBlendNormal);
+            }
+          }
+        }
+      }
+
+      numArgs = 0;
+    } else if (numArgs < maxArgs) {
+      args[numArgs++] = obj.copy();
+    }
+
+    obj = myParser.getObj();
+  }
+
+  return onlyNormalBlendMode;
+}
+
+
 bool Gfx::checkTransparencyGroup(Dict *resDict)
 {
     // check the effect of compositing objects as a group:
diff -ur poppler-23.09.0/poppler/Gfx.h poppler-23.09.0.patched/poppler/Gfx.h
--- poppler-23.09.0/poppler/Gfx.h	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/Gfx.h	2023-11-30 18:07:07.887433355 +0100
@@ -190,6 +190,9 @@
     // Get the current graphics state object.
     GfxState *getState() { return state; }
 
+  // Check whether a stream only contains normal blend mode (to enable subpixel rendering)
+  bool checkNormalBlendModeOnly(Object *str);
+
     bool checkTransparencyGroup(Dict *resDict);
 
     void drawForm(Object *str, Dict *resDict, const double *matrix, const double *bbox, bool transpGroup = false, bool softMask = false, GfxColorSpace *blendingColorSpace = nullptr, bool isolated = false, bool knockout = false,
diff -ur poppler-23.09.0/poppler/Page.cc poppler-23.09.0.patched/poppler/Page.cc
--- poppler-23.09.0/poppler/Page.cc	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/Page.cc	2023-11-30 18:23:43.977756338 +0100
@@ -344,6 +344,19 @@
     return dict ? dict->copy(xrefA) : nullptr;
 }
 
+bool Page::supportSubpixelRendering(OutputDev *out) {
+  bool supported = false;
+  PDFRectangle box;
+
+  Object obj = contents.fetch(xref);
+  if (!obj.isNull()) {
+    Gfx gfx(doc, out, attrs->getResourceDict(), &box, nullptr);
+    supported = gfx.checkNormalBlendModeOnly(&obj);
+  }
+
+  return supported;
+}
+
 void Page::replaceXRef(XRef *xrefA)
 {
     Dict *pageDict = pageObj.getDict()->copy(xrefA);
diff -ur poppler-23.09.0/poppler/Page.h poppler-23.09.0.patched/poppler/Page.h
--- poppler-23.09.0/poppler/Page.h	2023-09-05 23:15:14.000000000 +0200
+++ poppler-23.09.0.patched/poppler/Page.h	2023-11-30 18:07:07.887433355 +0100
@@ -178,6 +178,9 @@
     Object *getResourceDictObject();
     Dict *getResourceDictCopy(XRef *xrefA);
 
+  // Whether the content in this page supports subpixel rendering (lcdfilter)
+  bool supportSubpixelRendering(OutputDev *out);
+
     // Get annotations array.
     Object getAnnotsObject(XRef *xrefA = nullptr) { return annotsObj.fetch(xrefA ? xrefA : xref); }
     // Add a new annotation to the page