Disable baseline snapping, and enable rounding to integers for scroll…

… offsets again

The baseline snapping needs to be disabled so that the lines are
properly placed, and not snapped to pixels. While using integer based
scroll offsets greatly reduces the pressure on the Skia font cache.

src/renderer/fonts/font_loader.rs

@@ -27,6 +27,7 @@ pub struct FontPair {
 impl FontPair {
     fn new(key: FontKey, mut skia_font: Font) -> Option<FontPair> {
         skia_font.set_subpixel(true);
+        skia_font.set_baseline_snap(false);
         skia_font.set_hinting(font_hinting(&key.hinting));
         skia_font.set_edging(font_edging(&key.edging));
 

src/renderer/mod.rs

@@ -344,7 +344,7 @@ impl Renderer {
                 result.font_changed = true;
             }
             DrawCommand::LineSpaceChanged(new_linespace) => {
-                self.grid_renderer.update_linespace(new_linespace as f32);
+                self.grid_renderer.update_linespace(new_linespace);
                 result.font_changed = true;
             }
             DrawCommand::DefaultStyleChanged(new_style) => {

src/renderer/rendered_window.rs

@@ -231,7 +231,7 @@ impl RenderedWindow {
         let scroll_offset_lines = self.scroll_animation.position.floor();
         let scroll_offset = scroll_offset_lines - self.scroll_animation.position;
         let scroll_offset_lines = scroll_offset_lines as isize;
-        let scroll_offset_pixels = scroll_offset * grid_scale.0.height;
+        let scroll_offset_pixels = (scroll_offset * grid_scale.0.height).round();
         let line_height = grid_scale.0.height;
         let mut has_transparency = false;
 
@@ -249,7 +249,7 @@ impl RenderedWindow {
                         pixel_region.top()
                             + (scroll_offset_pixels
                                 + ((i + self.viewport_margins.top as isize) as f32
-                                    * grid_scale.0.height)) as f32,
+                                    * grid_scale.0.height)),
                     ));
                     (matrix, line)
                 })