DWrite: Support antialias and subpixel order font options

Create a new IDWriteRenderingParams object from the given font
options.

2 files changed, 145 insertions, 15 deletions

diff --git a/src/win32/cairo-dwrite-font.cpp b/src/win32/cairo-dwrite-font.cpp
index d1c4e63f1..d12f7b70b 100644
--- a/src/win32/cairo-dwrite-font.cpp
+++ b/src/win32/cairo-dwrite-font.cpp
@@ -212,6 +212,9 @@ private:
 
 
 RefPtr<IDWriteFactory> DWriteFactory::mFactoryInstance;
+RefPtr<IDWriteFactory1> DWriteFactory::mFactoryInstance1;
+RefPtr<IDWriteFactory2> DWriteFactory::mFactoryInstance2;
+RefPtr<IDWriteFactory3> DWriteFactory::mFactoryInstance3;
 RefPtr<IDWriteFactory4> DWriteFactory::mFactoryInstance4;
 
 RefPtr<IWICImagingFactory> WICImagingFactory::mFactoryInstance;
@@ -221,6 +224,107 @@ RefPtr<IDWriteRenderingParams> DWriteFactory::mDefaultRenderingParams;
 RefPtr<ID2D1Factory> D2DFactory::mFactoryInstance;
 RefPtr<ID2D1DCRenderTarget> D2DFactory::mRenderTarget;
 
+static int
+_quality_from_antialias_mode(cairo_antialias_t antialias)
+{
+    switch (antialias) {
+    case CAIRO_ANTIALIAS_NONE:
+	return NONANTIALIASED_QUALITY;
+    case CAIRO_ANTIALIAS_FAST:
+    case CAIRO_ANTIALIAS_GRAY:
+	return ANTIALIASED_QUALITY;
+    default:
+	break;
+    }
+    return CLEARTYPE_QUALITY;    
+}
+
+static RefPtr<IDWriteRenderingParams>
+_create_rendering_params(IDWriteRenderingParams     *params,
+			 const cairo_font_options_t *options,
+			 cairo_antialias_t           antialias)
+{
+    if (!params)
+	params = DWriteFactory::DefaultRenderingParams();
+    FLOAT gamma = params->GetGamma();
+    FLOAT enhanced_contrast = params->GetEnhancedContrast();
+    FLOAT clear_type_level = params->GetClearTypeLevel();
+    DWRITE_PIXEL_GEOMETRY pixel_geometry = params->GetPixelGeometry();
+    DWRITE_RENDERING_MODE rendering_mode = params->GetRenderingMode();
+
+    cairo_bool_t modified = FALSE;
+    switch (antialias) {
+    case CAIRO_ANTIALIAS_NONE:
+	if (rendering_mode != DWRITE_RENDERING_MODE_ALIASED) {
+	    rendering_mode = DWRITE_RENDERING_MODE_ALIASED;
+	    modified = TRUE;
+	}
+	break;
+    case CAIRO_ANTIALIAS_FAST:
+    case CAIRO_ANTIALIAS_GRAY:
+	if (clear_type_level) {
+	    clear_type_level = 0;
+	    modified = TRUE;
+	}
+	break;
+    default:
+	break;
+    }
+    auto subpixel_order = cairo_font_options_get_subpixel_order (options);
+    switch (subpixel_order) {
+    case CAIRO_SUBPIXEL_ORDER_RGB:
+	if (pixel_geometry != DWRITE_PIXEL_GEOMETRY_RGB) {
+	    pixel_geometry = DWRITE_PIXEL_GEOMETRY_RGB;
+	    modified = TRUE;
+	}
+	break;
+    case CAIRO_SUBPIXEL_ORDER_BGR:
+	if (pixel_geometry != DWRITE_PIXEL_GEOMETRY_BGR) {
+	    pixel_geometry = DWRITE_PIXEL_GEOMETRY_BGR;
+	    modified = TRUE;
+	}
+	break;
+    default:
+	break;
+    }	
+    if (!modified)
+	return params;
+
+    HRESULT hr;
+    RefPtr<IDWriteRenderingParams1> params1;
+    hr = params->QueryInterface(&params1);
+    if (FAILED(hr)) {
+	RefPtr<IDWriteRenderingParams> ret;
+	DWriteFactory::Instance()->CreateCustomRenderingParams(gamma, enhanced_contrast, clear_type_level, pixel_geometry, rendering_mode, &ret);
+	return ret;
+    }
+
+    FLOAT grayscaleEnhancedContrast = params1->GetGrayscaleEnhancedContrast();
+    RefPtr<IDWriteRenderingParams2> params2;
+    hr = params->QueryInterface(&params2);
+    if (FAILED(hr)) {
+	RefPtr<IDWriteRenderingParams1> ret;
+	DWriteFactory::Instance1()->CreateCustomRenderingParams(gamma, enhanced_contrast, grayscaleEnhancedContrast, clear_type_level, pixel_geometry, rendering_mode, &ret);
+	return ret;
+    }    
+
+    DWRITE_GRID_FIT_MODE gridFitMode = params2->GetGridFitMode();
+    RefPtr<IDWriteRenderingParams3> params3;
+    hr = params->QueryInterface(&params3);
+    if (FAILED(hr)) {
+	RefPtr<IDWriteRenderingParams2> ret;
+	DWriteFactory::Instance2()->CreateCustomRenderingParams(gamma, enhanced_contrast, grayscaleEnhancedContrast, clear_type_level, pixel_geometry, rendering_mode, gridFitMode, &ret);
+	return ret;
+    }    
+    
+    DWRITE_RENDERING_MODE1 rendering_mode1 = params3->GetRenderingMode1();
+    if (antialias == CAIRO_ANTIALIAS_NONE)
+	rendering_mode1 = DWRITE_RENDERING_MODE1_ALIASED;
+    RefPtr<IDWriteRenderingParams3> ret;
+    DWriteFactory::Instance3()->CreateCustomRenderingParams(gamma, enhanced_contrast, grayscaleEnhancedContrast, clear_type_level, pixel_geometry, rendering_mode1, gridFitMode, &ret);
+    return ret;
+}
+
 /* Functions #cairo_font_face_backend_t */
 static cairo_status_t
 _cairo_dwrite_font_face_create_for_toy (cairo_toy_font_face_t   *toy_face,
@@ -557,13 +661,6 @@ _cairo_dwrite_font_face_scaled_font_create (void			*abstract_face,
     dwrite_font->mat_inverse = dwrite_font->mat;
     cairo_matrix_invert (&dwrite_font->mat_inverse);
 
-    dwrite_font->rendering_params = NULL;
-    if (font_face->rendering_params) {
-	dwrite_font->rendering_params = font_face->rendering_params;
-	dwrite_font->rendering_params->AddRef();
-    }
-    dwrite_font->measuring_mode = font_face->measuring_mode;
-
     cairo_font_extents_t extents;
 
     DWRITE_FONT_METRICS metrics;
@@ -612,6 +709,9 @@ _cairo_dwrite_font_face_scaled_font_create (void			*abstract_face,
 	dwrite_font->antialias_mode = options->antialias;
     }
 
+    dwrite_font->rendering_params = _create_rendering_params(font_face->rendering_params, options, dwrite_font->antialias_mode).forget().drop();
+    dwrite_font->measuring_mode = font_face->measuring_mode;
+
     return _cairo_scaled_font_set_metrics (*font, &extents);
 }
 
@@ -1199,7 +1299,7 @@ _cairo_dwrite_scaled_font_init_glyph_surface(cairo_dwrite_scaled_font_t *scaled_
 
     GdiFlush();
 
-    image = _cairo_compute_glyph_mask (&surface->base, CLEARTYPE_QUALITY);
+    image = _cairo_compute_glyph_mask (&surface->base, _quality_from_antialias_mode(scaled_font->antialias_mode));
     status = (cairo_int_status_t)image->status;
     if (status)
 	goto FAIL;
@@ -1453,6 +1553,9 @@ cairo_dwrite_font_face_get_rendering_params (cairo_font_face_t *font_face)
  * @params: The #IDWriteRenderingParams object
  *
  * Sets the #IDWriteRenderingParams object to @font_face.
+ * This #IDWriteRenderingParams is used to render glyphs if default values of font options are used.
+ * If non-defalut values of font options are specified when creating a #cairo_scaled_font_t,
+ * cairo creates a new #IDWriteRenderingParams object for the #cairo_scaled_font_t object by overwriting the corresponding parameters.
  *
  * Since: 1.18
  **/
@@ -1526,12 +1629,6 @@ _dwrite_draw_glyphs_to_gdi_surface_gdi(cairo_win32_surface_t *surface,
 	}
     }
 
-    IDWriteRenderingParams *params;
-    if (scaled_font->rendering_params)
-	params = scaled_font->rendering_params;
-    else
-	params = DWriteFactory::DefaultRenderingParams();
-
     /*
      * We set the number of pixels per DIP to 1.0. This is because we always want
      * to draw in device pixels, and not device independent pixels. On high DPI
@@ -1556,7 +1653,7 @@ _dwrite_draw_glyphs_to_gdi_surface_gdi(cairo_win32_surface_t *surface,
 	   surface->dc,
 	   area.left, area.top,
 	   SRCCOPY | NOMIRRORBITMAP);
-    rt->DrawGlyphRun(x, y, scaled_font->measuring_mode, run, params, color);
+    rt->DrawGlyphRun(x, y, scaled_font->measuring_mode, run, scaled_font->rendering_params, color);
     BitBlt(surface->dc,
 	   area.left, area.top,
 	   area.right - area.left, area.bottom - area.top,
diff --git a/src/win32/cairo-dwrite-private.hpp b/src/win32/cairo-dwrite-private.hpp
index 5e91acf42..c7a24822a 100644
--- a/src/win32/cairo-dwrite-private.hpp
+++ b/src/win32/cairo-dwrite-private.hpp
@@ -99,6 +99,36 @@ public:
 	return mFactoryInstance;
     }
 
+    static RefPtr<IDWriteFactory1> Instance1()
+    {
+	if (!mFactoryInstance1) {
+	    if (Instance()) {
+		Instance()->QueryInterface(&mFactoryInstance1);
+	    }
+	}
+	return mFactoryInstance1;
+    }
+
+    static RefPtr<IDWriteFactory2> Instance2()
+    {
+	if (!mFactoryInstance2) {
+	    if (Instance()) {
+		Instance()->QueryInterface(&mFactoryInstance2);
+	    }
+	}
+	return mFactoryInstance2;
+    }
+
+    static RefPtr<IDWriteFactory3> Instance3()
+    {
+	if (!mFactoryInstance3) {
+	    if (Instance()) {
+		Instance()->QueryInterface(&mFactoryInstance3);
+	    }
+	}
+	return mFactoryInstance3;
+    }
+
     static RefPtr<IDWriteFactory4> Instance4()
     {
 	if (!mFactoryInstance4) {
@@ -149,6 +179,9 @@ public:
 
 private:
     static RefPtr<IDWriteFactory> mFactoryInstance;
+    static RefPtr<IDWriteFactory1> mFactoryInstance1;
+    static RefPtr<IDWriteFactory2> mFactoryInstance2;
+    static RefPtr<IDWriteFactory3> mFactoryInstance3;
     static RefPtr<IDWriteFactory4> mFactoryInstance4;
     static RefPtr<IDWriteFontCollection> mSystemCollection;
     static RefPtr<IDWriteRenderingParams> mDefaultRenderingParams;