Revert change to clear API

The new API ended up being awkward to use when you're doing stuff without a batcher (e.g. UI library integrations), so it needs a rethink. I'd like to get to a point where you can just call `clear` on the target itself, but that doesn't play nicely with `Window`...

examples/bunnymark.rs

@@ -123,12 +123,13 @@ impl EventHandler for GameState {
     }
 
     fn draw(&mut self, app: &mut App) {
+        app.gfx.clear(&app.window, Color::rgb(0.392, 0.584, 0.929));
+
         for bunny in &self.bunnies {
             self.batch
                 .texture(&self.texture, bunny.position, DrawParams::new());
         }
 
-        self.batch
-            .clear_and_draw(Color::rgb(0.392, 0.584, 0.929), &app.window);
+        self.batch.draw(&app.window);
     }
 }

src/graphics.rs

@@ -75,21 +75,25 @@ impl Graphics {
         }
     }
 
+    pub fn clear(&self, target: &impl Target, color: Color) {
+        unsafe {
+            target.bind(self);
+
+            self.state
+                .gl
+                .clear_color(color.r, color.g, color.b, color.a);
+
+            self.state.gl.clear(glow::COLOR_BUFFER_BIT);
+        }
+    }
+
     pub fn draw<T>(&self, pass: RenderPass<'_, T>)
     where
         T: Target,
     {
         unsafe {
             pass.target.bind(self);
 
-            if let Some(color) = pass.clear_color {
-                self.state
-                    .gl
-                    .clear_color(color.r, color.g, color.b, color.a);
-
-                self.state.gl.clear(glow::COLOR_BUFFER_BIT);
-            }
-
             self.bind_vertex_buffer(Some(pass.mesh.raw.vertex_buffer));
             self.bind_index_buffer(Some(pass.mesh.raw.index_buffer));
             self.bind_shader(Some(pass.shader.raw.id));
@@ -275,6 +279,4 @@ pub struct RenderPass<'a, T> {
 
     pub index_start: usize,
     pub index_count: usize,
-
-    pub clear_color: Option<Color>,
 }

src/graphics/batch.rs

@@ -151,7 +151,7 @@ impl Batcher {
         }
     }
 
-    fn draw_internal(&mut self, clear_color: Option<Color>, target: &impl Target) {
+    pub fn draw(&mut self, target: &impl Target) {
         let mut index = 0;
 
         for mut batch in self.batches.drain(..) {
@@ -174,8 +174,6 @@ impl Batcher {
 
                     index_start: 0,
                     index_count: num_sprites * 6,
-
-                    clear_color: clear_color.filter(|_| index == 0),
                 });
 
                 index += num_sprites;
@@ -188,14 +186,6 @@ impl Batcher {
         self.matrices.clear();
     }
 
-    pub fn clear_and_draw(&mut self, clear_color: Color, target: &impl Target) {
-        self.draw_internal(Some(clear_color), target)
-    }
-
-    pub fn draw(&mut self, target: &impl Target) {
-        self.draw_internal(None, target)
-    }
-
     pub fn push_matrix(&mut self, matrix: Mat3) {
         // TODO: Support relative transforms
         self.matrices.push(matrix);

src/graphics/scaling.rs

@@ -3,7 +3,7 @@ use glam::Vec2;
 use crate::graphics::Canvas;
 use crate::window::Window;
 
-use super::{Batcher, Color, DrawParams, Graphics, Target};
+use super::{Batcher, DrawParams, Graphics, Target};
 
 pub struct Scaler {
     canvas: Canvas,
@@ -31,7 +31,7 @@ impl Scaler {
             DrawParams::new().scale(scale),
         );
 
-        batch.clear_and_draw(Color::BLACK, target);
+        batch.draw(target);
 
         self.offset = offset;
         self.scale = scale;