Implement Geometry2D primitive

8 files changed, 278 insertions, 3 deletions

diff --git a/wgpu/src/geometry.rs b/wgpu/src/geometry.rs
new file mode 100644
index 00000000..f79e9c43
--- /dev/null
+++ b/wgpu/src/geometry.rs
@@ -0,0 +1,215 @@
+use crate::Transformation;
+use iced_native::{Geometry2D, Rectangle, Vertex2D};
+use std::mem;
+
+#[derive(Debug)]
+pub struct Pipeline {
+    pipeline: wgpu::RenderPipeline,
+    constants: wgpu::BindGroup,
+    constants_buffer: wgpu::Buffer,
+}
+
+impl Pipeline {
+    pub fn new(device: &mut wgpu::Device) -> Pipeline {
+        let constant_layout =
+            device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
+                bindings: &[wgpu::BindGroupLayoutBinding {
+                    binding: 0,
+                    visibility: wgpu::ShaderStage::VERTEX,
+                    ty: wgpu::BindingType::UniformBuffer { dynamic: false },
+                }],
+            });
+
+        let constants_buffer = device
+            .create_buffer_mapped(
+                1,
+                wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST,
+            )
+            .fill_from_slice(&[Uniforms::default()]);
+
+        let constant_bind_group =
+            device.create_bind_group(&wgpu::BindGroupDescriptor {
+                layout: &constant_layout,
+                bindings: &[wgpu::Binding {
+                    binding: 0,
+                    resource: wgpu::BindingResource::Buffer {
+                        buffer: &constants_buffer,
+                        range: 0..std::mem::size_of::<Uniforms>() as u64,
+                    },
+                }],
+            });
+
+        let layout =
+            device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
+                bind_group_layouts: &[&constant_layout],
+            });
+
+        let vs = include_bytes!("shader/geom2d.vert.spv");
+        let vs_module = device.create_shader_module(
+            &wgpu::read_spirv(std::io::Cursor::new(&vs[..]))
+                .expect("Read quad vertex shader as SPIR-V"),
+        );
+
+        let fs = include_bytes!("shader/geom2d.frag.spv");
+        let fs_module = device.create_shader_module(
+            &wgpu::read_spirv(std::io::Cursor::new(&fs[..]))
+                .expect("Read quad fragment shader as SPIR-V"),
+        );
+
+        let pipeline =
+            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                layout: &layout,
+                vertex_stage: wgpu::ProgrammableStageDescriptor {
+                    module: &vs_module,
+                    entry_point: "main",
+                },
+                fragment_stage: Some(wgpu::ProgrammableStageDescriptor {
+                    module: &fs_module,
+                    entry_point: "main",
+                }),
+                rasterization_state: Some(wgpu::RasterizationStateDescriptor {
+                    front_face: wgpu::FrontFace::Cw,
+                    cull_mode: wgpu::CullMode::None,
+                    depth_bias: 0,
+                    depth_bias_slope_scale: 0.0,
+                    depth_bias_clamp: 0.0,
+                }),
+                primitive_topology: wgpu::PrimitiveTopology::TriangleList,
+                color_states: &[wgpu::ColorStateDescriptor {
+                    format: wgpu::TextureFormat::Bgra8UnormSrgb,
+                    color_blend: wgpu::BlendDescriptor {
+                        src_factor: wgpu::BlendFactor::SrcAlpha,
+                        dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
+                        operation: wgpu::BlendOperation::Add,
+                    },
+                    alpha_blend: wgpu::BlendDescriptor {
+                        src_factor: wgpu::BlendFactor::One,
+                        dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
+                        operation: wgpu::BlendOperation::Add,
+                    },
+                    write_mask: wgpu::ColorWrite::ALL,
+                }],
+                depth_stencil_state: None,
+                index_format: wgpu::IndexFormat::Uint16,
+                vertex_buffers: &[wgpu::VertexBufferDescriptor {
+                    stride: mem::size_of::<Vertex2D>() as u64,
+                    step_mode: wgpu::InputStepMode::Vertex,
+                    attributes: &[
+                        // Position
+                        wgpu::VertexAttributeDescriptor {
+                            shader_location: 0,
+                            format: wgpu::VertexFormat::Float2,
+                            offset: 0,
+                        },
+                        // Color
+                        wgpu::VertexAttributeDescriptor {
+                            shader_location: 1,
+                            format: wgpu::VertexFormat::Float4,
+                            offset: 4 * 2,
+                        },
+                    ],
+                }],
+                sample_count: 1,
+                sample_mask: !0,
+                alpha_to_coverage_enabled: false,
+            });
+
+        Pipeline {
+            pipeline,
+            constants: constant_bind_group,
+            constants_buffer,
+        }
+    }
+
+    pub fn draw(
+        &mut self,
+        device: &mut wgpu::Device,
+        encoder: &mut wgpu::CommandEncoder,
+        target: &wgpu::TextureView,
+        transformation: Transformation,
+        scale: f32,
+        geometries: &Vec<Geometry2D>,
+        bounds: Rectangle<u32>,
+    ) {
+        let uniforms = Uniforms {
+            transform: transformation.into(),
+            scale,
+        };
+
+        let constants_buffer = device
+            .create_buffer_mapped(1, wgpu::BufferUsage::COPY_SRC)
+            .fill_from_slice(&[uniforms]);
+
+        encoder.copy_buffer_to_buffer(
+            &constants_buffer,
+            0,
+            &self.constants_buffer,
+            0,
+            std::mem::size_of::<Uniforms>() as u64,
+        );
+
+        for geom in geometries {
+            let vertices_buffer = device
+                .create_buffer_mapped(
+                    geom.vertices.len(),
+                    wgpu::BufferUsage::VERTEX,
+                )
+                .fill_from_slice(&geom.vertices);
+
+            let indices_buffer = device
+                .create_buffer_mapped(
+                    geom.indices.len(),
+                    wgpu::BufferUsage::INDEX,
+                )
+                .fill_from_slice(&geom.indices);
+
+            let mut render_pass =
+                encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
+                    color_attachments: &[
+                        wgpu::RenderPassColorAttachmentDescriptor {
+                            attachment: target,
+                            resolve_target: None,
+                            load_op: wgpu::LoadOp::Load,
+                            store_op: wgpu::StoreOp::Store,
+                            clear_color: wgpu::Color {
+                                r: 0.0,
+                                g: 0.0,
+                                b: 0.0,
+                                a: 0.0,
+                            },
+                        },
+                    ],
+                    depth_stencil_attachment: None,
+                });
+
+            render_pass.set_pipeline(&self.pipeline);
+            render_pass.set_bind_group(0, &self.constants, &[]);
+            render_pass.set_index_buffer(&indices_buffer, 0);
+            render_pass.set_vertex_buffers(0, &[(&vertices_buffer, 0)]);
+            render_pass.set_scissor_rect(
+                bounds.x,
+                bounds.y,
+                bounds.width,
+                bounds.height,
+            );
+
+            render_pass.draw_indexed(0..geom.indices.len() as u32, 0, 0..1);
+        }
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Clone, Copy)]
+struct Uniforms {
+    transform: [f32; 16],
+    scale: f32,
+}
+
+impl Default for Uniforms {
+    fn default() -> Self {
+        Self {
+            transform: *Transformation::identity().as_ref(),
+            scale: 1.0,
+        }
+    }
+}
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index 9f9ed8db..7587be77 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -30,6 +30,7 @@ mod quad;
 mod renderer;
 mod text;
 mod transformation;
+mod geometry;
 
 pub(crate) use crate::image::Image;
 pub(crate) use quad::Quad;
diff --git a/wgpu/src/primitive.rs b/wgpu/src/primitive.rs
index 6c61f800..06121262 100644
--- a/wgpu/src/primitive.rs
+++ b/wgpu/src/primitive.rs
@@ -1,6 +1,6 @@
 use iced_native::{
     image, svg, Background, Color, Font, HorizontalAlignment, Rectangle,
-    Vector, VerticalAlignment,
+    Vector, VerticalAlignment, Geometry2D,
 };
 
 /// A rendering primitive.
@@ -63,6 +63,11 @@ pub enum Primitive {
         /// The content of the clip
         content: Box<Primitive>,
     },
+    /// A low-level geometry primitive
+    Geometry2D {
+        /// The vertices and indices of the geometry
+        geometry: Geometry2D,
+    },
 }
 
 impl Default for Primitive {
diff --git a/wgpu/src/renderer.rs b/wgpu/src/renderer.rs
index 365ef1ef..3cfd746d 100644
--- a/wgpu/src/renderer.rs
+++ b/wgpu/src/renderer.rs
@@ -1,7 +1,10 @@
-use crate::{image, quad, text, Image, Primitive, Quad, Transformation};
+use crate::{
+    geometry, image, quad, text, Image, Primitive, Quad, Transformation,
+};
 use iced_native::{
     renderer::{Debugger, Windowed},
-    Background, Color, Layout, MouseCursor, Point, Rectangle, Vector, Widget,
+    Background, Color, Geometry2D, Layout, MouseCursor, Point, Rectangle,
+    Vector, Widget,
 };
 
 use wgpu::{
@@ -24,6 +27,7 @@ pub struct Renderer {
     quad_pipeline: quad::Pipeline,
     image_pipeline: crate::image::Pipeline,
     text_pipeline: text::Pipeline,
+    geometry_pipeline: crate::geometry::Pipeline,
 }
 
 struct Layer<'a> {
@@ -31,6 +35,7 @@ struct Layer<'a> {
     offset: Vector<u32>,
     quads: Vec<Quad>,
     images: Vec<Image>,
+    geometries: Vec<Geometry2D>,
     text: Vec<wgpu_glyph::Section<'a>>,
 }
 
@@ -42,6 +47,7 @@ impl<'a> Layer<'a> {
             quads: Vec::new(),
             images: Vec::new(),
             text: Vec::new(),
+            geometries: Vec::new(),
         }
     }
 }
@@ -64,6 +70,7 @@ impl Renderer {
         let text_pipeline = text::Pipeline::new(&mut device);
         let quad_pipeline = quad::Pipeline::new(&mut device);
         let image_pipeline = crate::image::Pipeline::new(&mut device);
+        let geometry_pipeline = geometry::Pipeline::new(&mut device);
 
         Self {
             device,
@@ -71,6 +78,7 @@ impl Renderer {
             quad_pipeline,
             image_pipeline,
             text_pipeline,
+            geometry_pipeline,
         }
     }
 
@@ -244,6 +252,9 @@ impl Renderer {
                     scale: [bounds.width, bounds.height],
                 });
             }
+            Primitive::Geometry2D { geometry } => {
+                layer.geometries.push(geometry.clone());
+            }
             Primitive::Clip {
                 bounds,
                 offset,
@@ -401,6 +412,24 @@ impl Renderer {
                 },
             );
         }
+
+        if layer.geometries.len() > 0 {
+            let translated = transformation
+                * Transformation::translate(
+                    -(layer.offset.x as f32) * dpi,
+                    -(layer.offset.y as f32) * dpi,
+                );
+
+            self.geometry_pipeline.draw(
+                &mut self.device,
+                encoder,
+                target,
+                translated,
+                dpi,
+                &layer.geometries,
+                bounds,
+            );
+        }
     }
 }
 
diff --git a/wgpu/src/shader/geom2d.frag b/wgpu/src/shader/geom2d.frag
new file mode 100644
index 00000000..e39c45e7
--- /dev/null
+++ b/wgpu/src/shader/geom2d.frag
@@ -0,0 +1,8 @@
+#version 450
+
+layout(location = 0) in vec4 i_Color;
+layout(location = 0) out vec4 o_Color;
+
+void main() {
+    o_Color = i_Color;
+}
diff --git a/wgpu/src/shader/geom2d.frag.spv b/wgpu/src/shader/geom2d.frag.spv
new file mode 100644
index 00000000..c0165bca
--- /dev/null
+++ b/wgpu/src/shader/geom2d.frag.spv
diff --git a/wgpu/src/shader/geom2d.vert b/wgpu/src/shader/geom2d.vert
new file mode 100644
index 00000000..fd86ecd6
--- /dev/null
+++ b/wgpu/src/shader/geom2d.vert
@@ -0,0 +1,17 @@
+#version 450
+
+layout(location = 0) in vec2 i_Position;
+layout(location = 1) in vec4 i_Color;
+
+layout(location = 0) out vec4 o_Color;
+
+layout (set = 0, binding = 0) uniform Globals {
+    mat4 u_Transform;
+    float u_Scale;
+};
+
+void main() {
+    vec2 p_Position = i_Position * u_Scale;
+    gl_Position = u_Transform * vec4(p_Position, 0.0, 1.0);
+    o_Color = i_Color;
+}
diff --git a/wgpu/src/shader/geom2d.vert.spv b/wgpu/src/shader/geom2d.vert.spv
new file mode 100644
index 00000000..c15c7451
--- /dev/null
+++ b/wgpu/src/shader/geom2d.vert.spv