From 17356311d6fbefca224e66401e661d10c0c5a5a9 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Tue, 23 Jun 2020 13:05:43 -0700
Subject: [PATCH] Rework renderer options

---
 renderer/src/gpu/options.rs | 55 +++++++++++++++++++++++++++++++++----
 renderer/src/options.rs     | 46 +++++++++++++++++++++++++------
 2 files changed, 88 insertions(+), 13 deletions(-)

diff --git a/renderer/src/gpu/options.rs b/renderer/src/gpu/options.rs
index 435a6317..e5b6aa97 100644
--- a/renderer/src/gpu/options.rs
+++ b/renderer/src/gpu/options.rs
@@ -11,13 +11,58 @@
 use pathfinder_color::ColorF;
 use pathfinder_geometry::rect::RectI;
 use pathfinder_geometry::vector::Vector2I;
-use pathfinder_gpu::Device;
+use pathfinder_gpu::{Device, FeatureLevel};
 
-/// Options that influence rendering.
-#[derive(Default)]
-pub struct RendererOptions {
+/// Renderer options that can't be changed after the renderer is created.
+pub struct RendererMode {
+    /// The level of hardware features that the renderer will attempt to use.
+    pub level: RendererLevel,
+}
+
+/// Options that influence rendering that can be changed at runtime.
+pub struct RendererOptions<D> where D: Device {
+    /// Where the rendering should go: either to the default framebuffer (i.e. screen) or to a
+    /// custom framebuffer.
+    pub dest: DestFramebuffer<D>,
+    /// The background color. If not present, transparent is assumed.
     pub background_color: Option<ColorF>,
-    pub no_compute: bool,
+    /// Whether to display the debug UI.
+    pub show_debug_ui: bool,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum RendererLevel {
+    /// Direct3D 9/OpenGL 3.0/WebGL 2.0 compatibility. Bin on CPU, fill and composite on GPU.
+    D3D9,
+    /// Direct3D 11/OpenGL 4.3/Metal/Vulkan/WebGPU compatibility. Bin, fill, and composite on GPU.
+    D3D11,
+}
+
+impl RendererMode {
+    #[inline]
+    pub fn default_for_device<D>(device: &D) -> RendererMode where D: Device {
+        RendererMode { level: RendererLevel::default_for_device(device) }
+    }
+}
+
+impl<D> Default for RendererOptions<D> where D: Device {
+    #[inline]
+    fn default() -> RendererOptions<D> {
+        RendererOptions {
+            dest: DestFramebuffer::default(),
+            background_color: None,
+            show_debug_ui: false,
+        }
+    }
+}
+
+impl RendererLevel {
+    pub fn default_for_device<D>(device: &D) -> RendererLevel where D: Device {
+        match device.feature_level() {
+            FeatureLevel::D3D10 => RendererLevel::D3D9,
+            FeatureLevel::D3D11 => RendererLevel::D3D11,
+        }
+    }
 }
 
 #[derive(Clone)]
diff --git a/renderer/src/options.rs b/renderer/src/options.rs
index 86ba541e..646bdda4 100644
--- a/renderer/src/options.rs
+++ b/renderer/src/options.rs
@@ -10,6 +10,7 @@
 
 //! Options that control how rendering is to be performed.
 
+use crate::gpu::options::RendererLevel;
 use crate::gpu_data::RenderCommand;
 use pathfinder_geometry::rect::RectF;
 use pathfinder_geometry::transform2d::Transform2F;
@@ -17,17 +18,21 @@ use pathfinder_geometry::transform3d::Perspective;
 use pathfinder_geometry::vector::{Vector2F, Vector4F};
 use pathfinder_content::clip::PolygonClipper3D;
 
-pub trait RenderCommandListener: Send + Sync {
-    fn send(&self, command: RenderCommand);
+pub struct RenderCommandListener<'a> {
+    send_fn: RenderCommandSendFunction<'a>,
 }
 
-impl<F> RenderCommandListener for F
-where
-    F: Fn(RenderCommand) + Send + Sync,
-{
+pub type RenderCommandSendFunction<'a> = Box<dyn Fn(RenderCommand) + Send + Sync + 'a>;
+
+impl<'a> RenderCommandListener<'a> {
     #[inline]
-    fn send(&self, command: RenderCommand) {
-        (*self)(command)
+    pub fn new(send_fn: RenderCommandSendFunction<'a>) -> RenderCommandListener<'a> {
+        RenderCommandListener { send_fn }
+    }
+
+    #[inline]
+    pub fn send(&self, render_command: RenderCommand) {
+        (self.send_fn)(render_command)
     }
 }
 
@@ -120,6 +125,13 @@ pub(crate) struct PreparedBuildOptions {
     pub(crate) subpixel_aa_enabled: bool,
 }
 
+#[derive(Clone, Copy)]
+pub(crate) enum PrepareMode {
+    CPU,
+    TransformCPUBinGPU,
+    GPU { transform: Transform2F },
+}
+
 impl PreparedBuildOptions {
     #[inline]
     pub(crate) fn bounding_quad(&self) -> BoundingQuad {
@@ -128,6 +140,24 @@ impl PreparedBuildOptions {
             _ => [Vector4F::default(); 4],
         }
     }
+
+    #[inline]
+    pub(crate) fn to_prepare_mode(&self, renderer_level: RendererLevel) -> PrepareMode {
+        match renderer_level {
+            RendererLevel::D3D9 => PrepareMode::CPU,
+            RendererLevel::D3D11 => {
+                match self.transform {
+                    PreparedRenderTransform::Perspective { .. } => PrepareMode::TransformCPUBinGPU,
+                    PreparedRenderTransform::None => {
+                        PrepareMode::GPU { transform: Transform2F::default() }
+                    }
+                    PreparedRenderTransform::Transform2D(transform) => {
+                        PrepareMode::GPU { transform }
+                    }
+                }
+            }
+        }
+    }
 }
 
 pub(crate) type BoundingQuad = [Vector4F; 4];