[cairo] Implement blend mdoes in cairo backend

It requires cairo from git master to work at the moment. Fixes bugs
 #22384, #12979, #13603, #17919, #22255

3 files changed, 87 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index 0494c926..1942393b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -259,6 +259,9 @@ elif test x$enable_cairo_output = xtry; then
                     [enable_cairo_output="no"])
 fi
 
+AC_SUBST(CAIRO_CFLAGS)
+AC_SUBST(CAIRO_LIBS)
+
 AM_CONDITIONAL(BUILD_CAIRO_OUTPUT, test x$enable_cairo_output = xyes)
 AH_TEMPLATE([HAVE_CAIRO], [Use cairo for rendering.])
 if test x$enable_cairo_output = xyes; then
@@ -266,6 +269,30 @@ if test x$enable_cairo_output = xyes; then
   CAIRO_FEATURE="#define POPPLER_HAS_CAIRO 1"
   CAIRO_REQ="cairo"
   AC_CHECK_HEADERS(fcntl.h sys/mman.h sys/stat.h)
+  AC_LANG_PUSH([C])
+  _SAVE_CFLAGS=$CFLAGS
+  _SAVE_LIBS=$LIBS
+  CFLAGS="$CFLAGS $CAIRO_CFLAGS"
+  LIBS="$LIBS $CAIRO_LIBS"
+  AC_CACHE_CHECK([for cairo blend modes support],
+                 ac_cv_cairo_has_blend_modes,
+		 [AC_COMPILE_IFELSE(
+		   [AC_LANG_SOURCE([[
+#include <cairo.h>
+int main() {
+  cairo_t *cr;
+  cairo_set_operator(cr, CAIRO_OPERATOR_MULTIPLY);
+  return 0;
+}
+                   ]])],
+		   [ac_cv_cairo_has_blend_modes="yes"],
+                   [ac_cv_cairo_has_blend_modes="no"])])
+  CFLAGS=$_SAVE_CFLAGS
+  LIBS=$_SAVE_LIBS
+  AC_LANG_POP([C])
+  if test "$ac_cv_cairo_has_blend_modes" = "yes"; then
+    AC_DEFINE(CAIRO_HAS_BLEND_MODES, [1], [Whether cairo has blend modes support])
+  fi
 else
   CAIRO_FEATURE="#undef POPPLER_HAS_CAIRO"
   CAIRO_REQ=""
diff --git a/poppler/CairoOutputDev.cc b/poppler/CairoOutputDev.cc
index 670ae402..d1f5f3cd 100644
--- a/poppler/CairoOutputDev.cc
+++ b/poppler/CairoOutputDev.cc
@@ -263,6 +263,7 @@ void CairoOutputDev::restoreState(GfxState *state) {
   updateStrokeColor(state);
   updateFillOpacity(state);
   updateStrokeOpacity(state);
+  updateBlendMode(state);
 
   MaskStack* ms = maskStack;
   if (mask)
@@ -284,6 +285,7 @@ void CairoOutputDev::updateAll(GfxState *state) {
   updateStrokeColor(state);
   updateFillOpacity(state);
   updateStrokeOpacity(state);
+  updateBlendMode(state);
   needFontUpdate = gTrue;
 }
 
@@ -470,6 +472,63 @@ void CairoOutputDev::updateFillColorStop(GfxState *state, double offset) {
 	      offset, fill_color.r, fill_color.g, fill_color.b));
 }
 
+void CairoOutputDev::updateBlendMode(GfxState *state) {
+#ifdef CAIRO_HAS_BLEND_MODES
+  switch (state->getBlendMode()) {
+  default:
+  case gfxBlendNormal:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_OVER);
+    break;
+  case gfxBlendMultiply:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_MULTIPLY);
+    break;
+  case gfxBlendScreen:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_SCREEN);
+    break;
+  case gfxBlendOverlay:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_OVERLAY);
+    break;
+  case gfxBlendDarken:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_DARKEN);
+    break;
+  case gfxBlendLighten:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_LIGHTEN);
+    break;
+  case gfxBlendColorDodge:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_COLOR_DODGE);
+    break;
+  case gfxBlendColorBurn:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_COLOR_BURN);
+    break;
+  case gfxBlendHardLight:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_HARD_LIGHT);
+    break;
+  case gfxBlendSoftLight:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_SOFT_LIGHT);
+    break;
+  case gfxBlendDifference:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_DIFFERENCE);
+    break;
+  case gfxBlendExclusion:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_EXCLUSION);
+    break;
+  case gfxBlendHue:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_HSL_HUE);
+    break;
+  case gfxBlendSaturation:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_HSL_SATURATION);
+    break;
+  case gfxBlendColor:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_HSL_COLOR);
+    break;
+  case gfxBlendLuminosity:
+    cairo_set_operator (cairo, CAIRO_OPERATOR_HSL_LUMINOSITY);
+    break;
+  }
+  LOG(printf ("blend mode: %d\n", (int)state->getBlendMode()));
+#endif /* CAIRO_HAS_BLEND_MODES */
+}
+
 void CairoOutputDev::updateFont(GfxState *state) {
   cairo_font_face_t *font_face;
   cairo_matrix_t matrix, invert_matrix;
diff --git a/poppler/CairoOutputDev.h b/poppler/CairoOutputDev.h
index cd66cb78..f25e4028 100644
--- a/poppler/CairoOutputDev.h
+++ b/poppler/CairoOutputDev.h
@@ -141,6 +141,7 @@ public:
   virtual void updateFillOpacity(GfxState *state);
   virtual void updateStrokeOpacity(GfxState *state);
   virtual void updateFillColorStop(GfxState *state, double offset);
+  virtual void updateBlendMode(GfxState *state);
 
   //----- update text state
   virtual void updateFont(GfxState *state);