remove the use of bitmap scaler

Junkui Zhang created 4 months ago

Change summary

crates/gpui/src/platform/windows/direct_write.rs | 67 +++++------------
1 file changed, 22 insertions(+), 45 deletions(-)

Detailed changes

crates/gpui/src/platform/windows/direct_write.rs

@@ -775,12 +775,6 @@ impl DirectWriteState {
             )?;
         }
 
-        let antialias_mode = if params.is_emoji {
-            DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE
-        } else {
-            DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE
-        };
-
         let glyph_analysis = unsafe {
             self.components.factory.CreateGlyphRunAnalysis(
                 &glyph_run,
@@ -788,7 +782,7 @@ impl DirectWriteState {
                 rendering_mode,
                 DWRITE_MEASURING_MODE_NATURAL,
                 grid_fit_mode,
-                antialias_mode,
+                DWRITE_TEXT_ANTIALIAS_MODE_CLEARTYPE,
                 baseline_origin_x,
                 baseline_origin_y,
             )
@@ -854,48 +848,41 @@ impl DirectWriteState {
             anyhow::bail!("glyph bounds are empty");
         }
 
-        let bitmap_size = glyph_bounds.size;
-
-        let mut bitmap_data: Vec<u8>;
-        if params.is_emoji {
-            let glyph_analysis = self.create_glyph_run_analysis(params)?;
-
+        let bitmap_data = if params.is_emoji {
             if let Ok(color) = self.rasterize_color(&params, glyph_bounds) {
-                bitmap_data = color;
+                color
             } else {
-                let monochrome = self.rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
-                bitmap_data = monochrome
+                let monochrome = self.rasterize_monochrome(params, glyph_bounds)?;
+                monochrome
                     .into_iter()
                     .flat_map(|pixel| [0, 0, 0, pixel])
-                    .collect::<Vec<_>>();
+                    .collect::<Vec<_>>()
             }
         } else {
-            let glyph_analysis = self.create_glyph_run_analysis(params)?;
-            bitmap_data = self.rasterize_monochrome(&glyph_analysis, glyph_bounds)?;
-        }
+            self.rasterize_monochrome(params, glyph_bounds)?
+        };
 
-        Ok((bitmap_size, bitmap_data))
+        Ok((glyph_bounds.size, bitmap_data))
     }
 
     fn rasterize_monochrome(
         &self,
-        glyph_analysis: &IDWriteGlyphRunAnalysis,
+        params: &RenderGlyphParams,
         glyph_bounds: Bounds<DevicePixels>,
     ) -> Result<Vec<u8>> {
-        let multisampled_bounds =
-            unsafe { glyph_analysis.GetAlphaTextureBounds(DWRITE_TEXTURE_CLEARTYPE_3x1)? };
-        let multisampled_size = size(
-            multisampled_bounds.right - multisampled_bounds.left,
-            multisampled_bounds.bottom - multisampled_bounds.top,
-        );
-
         let mut bitmap_data =
-            vec![0u8; multisampled_size.width as usize * multisampled_size.height as usize * 3];
+            vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize * 3];
 
+        let glyph_analysis = self.create_glyph_run_analysis(params)?;
         unsafe {
             glyph_analysis.CreateAlphaTexture(
                 DWRITE_TEXTURE_CLEARTYPE_3x1,
-                &multisampled_bounds,
+                &RECT {
+                    left: glyph_bounds.origin.x.0,
+                    top: glyph_bounds.origin.y.0,
+                    right: glyph_bounds.size.width.0 + glyph_bounds.origin.x.0,
+                    bottom: glyph_bounds.size.height.0 + glyph_bounds.origin.y.0,
+                },
                 &mut bitmap_data,
             )?;
         }
@@ -903,10 +890,10 @@ impl DirectWriteState {
         let bitmap_factory = self.components.bitmap_factory.resolve()?;
         let bitmap = unsafe {
             bitmap_factory.CreateBitmapFromMemory(
-                multisampled_size.width as u32,
-                multisampled_size.height as u32,
+                glyph_bounds.size.width.0 as u32,
+                glyph_bounds.size.height.0 as u32,
                 &GUID_WICPixelFormat24bppRGB,
-                multisampled_size.width as u32 * 3,
+                glyph_bounds.size.width.0 as u32 * 3,
                 &bitmap_data,
             )
         }?;
@@ -914,20 +901,10 @@ impl DirectWriteState {
         let grayscale_bitmap =
             unsafe { WICConvertBitmapSource(&GUID_WICPixelFormat8bppGray, &bitmap) }?;
 
-        let scaler = unsafe { bitmap_factory.CreateBitmapScaler() }?;
-        unsafe {
-            scaler.Initialize(
-                &grayscale_bitmap,
-                glyph_bounds.size.width.0 as u32,
-                glyph_bounds.size.height.0 as u32,
-                WICBitmapInterpolationModeHighQualityCubic,
-            )
-        }?;
-
         let mut bitmap_data =
             vec![0u8; glyph_bounds.size.width.0 as usize * glyph_bounds.size.height.0 as usize];
         unsafe {
-            scaler.CopyPixels(
+            grayscale_bitmap.CopyPixels(
                 std::ptr::null() as _,
                 glyph_bounds.size.width.0 as u32,
                 &mut bitmap_data,