1 files changed, 107 insertions, 0 deletions
diff --git a/third_party/rust/dwrote/src/glyph_run_analysis.rs b/third_party/rust/dwrote/src/glyph_run_analysis.rs
new file mode 100644
index 0000000000..5224c60bc9
--- /dev/null
+++ b/third_party/rust/dwrote/src/glyph_run_analysis.rs
@@ -0,0 +1,107 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::cell::UnsafeCell;
+use std::mem;
+use std::ptr;
+use winapi::shared::windef::RECT;
+use winapi::um::dcommon::DWRITE_MEASURING_MODE;
+use winapi::um::dwrite::DWRITE_TEXTURE_CLEARTYPE_3x1;
+use winapi::um::dwrite::IDWriteGlyphRunAnalysis;
+use winapi::um::dwrite::{DWRITE_TEXTURE_ALIASED_1x1, DWRITE_GLYPH_RUN, DWRITE_TEXTURE_TYPE};
+use winapi::um::dwrite::{DWRITE_MATRIX, DWRITE_RENDERING_MODE};
+use winapi::um::winnt::HRESULT;
+use wio::com::ComPtr;
+
+use super::DWriteFactory;
+
+pub struct GlyphRunAnalysis {
+    native: UnsafeCell<ComPtr<IDWriteGlyphRunAnalysis>>,
+}
+
+impl GlyphRunAnalysis {
+    pub fn create(
+        glyph_run: &DWRITE_GLYPH_RUN,
+        pixels_per_dip: f32,
+        transform: Option<DWRITE_MATRIX>,
+        rendering_mode: DWRITE_RENDERING_MODE,
+        measuring_mode: DWRITE_MEASURING_MODE,
+        baseline_x: f32,
+        baseline_y: f32,
+    ) -> Result<GlyphRunAnalysis, HRESULT> {
+        unsafe {
+            let mut native: *mut IDWriteGlyphRunAnalysis = ptr::null_mut();
+            let hr = (*DWriteFactory()).CreateGlyphRunAnalysis(
+                glyph_run as *const DWRITE_GLYPH_RUN,
+                pixels_per_dip,
+                transform
+                    .as_ref()
+                    .map(|x| x as *const _)
+                    .unwrap_or(ptr::null()),
+                rendering_mode,
+                measuring_mode,
+                baseline_x,
+                baseline_y,
+                &mut native,
+            );
+            if hr != 0 {
+                Err(hr)
+            } else {
+                Ok(GlyphRunAnalysis::take(ComPtr::from_raw(native)))
+            }
+        }
+    }
+
+    pub fn take(native: ComPtr<IDWriteGlyphRunAnalysis>) -> GlyphRunAnalysis {
+        GlyphRunAnalysis {
+            native: UnsafeCell::new(native),
+        }
+    }
+
+    pub fn get_alpha_texture_bounds(
+        &self,
+        texture_type: DWRITE_TEXTURE_TYPE,
+    ) -> Result<RECT, HRESULT> {
+        unsafe {
+            let mut rect: RECT = mem::zeroed();
+            rect.left = 1234;
+            rect.top = 1234;
+            let hr = (*self.native.get()).GetAlphaTextureBounds(texture_type, &mut rect);
+            if hr != 0 {
+                Err(hr)
+            } else {
+                Ok(rect)
+            }
+        }
+    }
+
+    pub fn create_alpha_texture(
+        &self,
+        texture_type: DWRITE_TEXTURE_TYPE,
+        rect: RECT,
+    ) -> Result<Vec<u8>, HRESULT> {
+        unsafe {
+            let rect_pixels = (rect.right - rect.left) * (rect.bottom - rect.top);
+            let rect_bytes = rect_pixels
+                * match texture_type {
+                    DWRITE_TEXTURE_ALIASED_1x1 => 1,
+                    DWRITE_TEXTURE_CLEARTYPE_3x1 => 3,
+                    _ => panic!("bad texture type specified"),
+                };
+
+            let mut out_bytes: Vec<u8> = vec![0; rect_bytes as usize];
+            let hr = (*self.native.get()).CreateAlphaTexture(
+                texture_type,
+                &rect,
+                out_bytes.as_mut_ptr(),
+                out_bytes.len() as u32,
+            );
+            if hr != 0 {
+                Err(hr)
+            } else {
+                Ok(out_bytes)
+            }
+        }
+    }
+}