re #3. Improve text sharpness.

Should use `textureLoad` instead of `textureSample`.

src/lib.rs

@@ -564,8 +564,6 @@ impl Vger {
     pub fn text(&mut self, text: &str, size: u32, color: Color, max_width: Option<f32>) {
         self.setup_layout(text, size, max_width);
 
-        let padding = 2.0_f32;
-
         let scale = self.device_px_ratio;
         let scaled_size = size as f32 * scale;
 
@@ -588,21 +586,21 @@ impl Vger {
                 assert!(glyph.height == rect.height as usize);
 
                 prim.quad_bounds = [
-                    (glyph.x - padding) / scale,
-                    (glyph.y - padding) / scale,
-                    (glyph.x + padding + glyph.width as f32) / scale,
-                    (glyph.y + padding + glyph.height as f32) / scale,
+                    (glyph.x),
+                    (glyph.y),
+                    (glyph.x + glyph.width as f32),
+                    (glyph.y + glyph.height as f32),
                 ];
                 // println!("quad_bounds: {:?}", prim.quad_bounds);
 
                 // The extra +/- 1.0 offset ensures we cover the same
                 // number of pixels when rasterizing as the glyph
                 // in the texture.
                 prim.tex_bounds = [
-                    rect.x as f32 - padding,
-                    (rect.y + rect.height) as f32 + padding,
-                    (rect.x + rect.width) as f32 + padding + 1.0,
-                    rect.y as f32 - padding - 1.0,
+                    rect.x as f32,
+                    (rect.y + rect.height) as f32,
+                    (rect.x + rect.width) as f32,
+                    rect.y as f32,
                 ];
                 prim.paint = paint.index as u32;
                 // println!("tex_bounds: {:?}", prim.tex_bounds);

src/shader.wgsl

@@ -617,8 +617,8 @@ fn fs_main(
     let scissor = scissors.scissors[prim.scissor];
 
     // Look up glyph alpha (if not a glyph, still have to because of wgsl).
-    let a = textureSample(glyph_atlas, samp, (in.t+0.5)/1024.0).r;
-    // let a = textureLoad(glyph_atlas, vec2<i32>(in.t), 0).r;
+    // let a = textureSample(glyph_atlas, samp, (in.t+0.5)/1024.0).r;
+    let a = textureLoad(glyph_atlas, vec2<i32>(in.t), 0).r;
 
     let s = scissor_mask(scissor, in.p);
 
@@ -627,9 +627,6 @@ fn fs_main(
         let c = paint.inner_color;
         var color = vec4<f32>(c.rgb, a);
 
-        //auto c = paint.innerColor;
-        //auto color = float4(c.rgb, c.a * glyphs.sample(glyphSampler, in.t).a);
-
         //if(glow) {
         //    color.a *= paint.glow;
         //}