BREP_render 0.1.0

use super::*;

impl RenderCore {
    pub fn new(device: wgpu::Device, queue: wgpu::Queue, format: wgpu::TextureFormat) -> Self {
        let shader = device.create_shader_module(wgpu::ShaderModuleDescriptor {
            label: Some("brep-render shaders"),
            source: wgpu::ShaderSource::Wgsl(include_str!("../shaders.wgsl").into()),
        });

        let globals_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
            label: Some("globals"),
            entries: &[wgpu::BindGroupLayoutEntry {
                binding: 0,
                visibility: wgpu::ShaderStages::VERTEX_FRAGMENT,
                ty: wgpu::BindingType::Buffer {
                    ty: wgpu::BufferBindingType::Uniform,
                    has_dynamic_offset: false,
                    min_binding_size: None,
                },
                count: None,
            }],
        });
        let style_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
            label: Some("style"),
            entries: &[wgpu::BindGroupLayoutEntry {
                binding: 0,
                visibility: wgpu::ShaderStages::VERTEX_FRAGMENT,
                ty: wgpu::BindingType::Buffer {
                    ty: wgpu::BufferBindingType::Uniform,
                    has_dynamic_offset: false,
                    min_binding_size: None,
                },
                count: None,
            }],
        });
        let globals_buf = device.create_buffer(&wgpu::BufferDescriptor {
            label: Some("globals"),
            size: std::mem::size_of::<Globals>() as u64,
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
            mapped_at_creation: false,
        });
        let globals_bind = device.create_bind_group(&wgpu::BindGroupDescriptor {
            label: Some("globals"),
            layout: &globals_layout,
            entries: &[wgpu::BindGroupEntry {
                binding: 0,
                resource: globals_buf.as_entire_binding(),
            }],
        });

        let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
            label: Some("brep-render"),
            bind_group_layouts: &[Some(&globals_layout), Some(&style_layout)],
            immediate_size: 0,
        });

        const ALPHA_BLEND: wgpu::BlendState = wgpu::BlendState::ALPHA_BLENDING;
        let color_target = |blend: Option<wgpu::BlendState>| {
            Some(wgpu::ColorTargetState {
                format,
                blend,
                write_mask: wgpu::ColorWrites::ALL,
            })
        };
        let multisample = wgpu::MultisampleState {
            count: SAMPLES,
            ..Default::default()
        };

        let mesh_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("mesh"),
            layout: Some(&pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: Some("vs_mesh"),
                compilation_options: Default::default(),
                buffers: &[wgpu::VertexBufferLayout {
                    array_stride: std::mem::size_of::<MeshVertex>() as u64,
                    step_mode: wgpu::VertexStepMode::Vertex,
                    attributes: &wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3],
                }],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: Some("fs_mesh"),
                compilation_options: Default::default(),
                targets: &[color_target(None)],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::TriangleList,
                front_face: wgpu::FrontFace::Ccw,
                // Double-sided, like the retired materials during picking — and
                // the +plane-z winding convention (R13) is never "corrected".
                cull_mode: None,
                ..Default::default()
            },
            depth_stencil: Some(wgpu::DepthStencilState {
                format: DEPTH_FORMAT,
                depth_write_enabled: Some(true),
                depth_compare: Some(wgpu::CompareFunction::Less),
                stencil: Default::default(),
                // Push faces slightly back so the edge overlay wins its
                // z-fight against the faces it outlines.
                bias: wgpu::DepthBiasState {
                    constant: 4,
                    slope_scale: 2.0,
                    clamp: 0.0,
                },
            }),
            multisample,
            multiview_mask: None,
            cache: None,
        });

        // Wireframe: same vertex layout as the mesh, but drawn as a line list
        // (each triangle's 3 edges) with a flat fragment. `PolygonMode::Line`
        // is unavailable on the WebGL/downlevel path, so we expand to lines.
        let wire_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("wireframe"),
            layout: Some(&pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: Some("vs_mesh"),
                compilation_options: Default::default(),
                buffers: &[wgpu::VertexBufferLayout {
                    array_stride: std::mem::size_of::<MeshVertex>() as u64,
                    step_mode: wgpu::VertexStepMode::Vertex,
                    attributes: &wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3],
                }],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: Some("fs_wire"),
                compilation_options: Default::default(),
                targets: &[color_target(None)],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::LineList,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: None,
                ..Default::default()
            },
            depth_stencil: Some(wgpu::DepthStencilState {
                format: DEPTH_FORMAT,
                depth_write_enabled: Some(true),
                depth_compare: Some(wgpu::CompareFunction::Less),
                stencil: Default::default(),
                bias: Default::default(),
            }),
            multisample,
            multiview_mask: None,
            cache: None,
        });

        let edge_pipeline = |label: &str, depth_compare: wgpu::CompareFunction| {
            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
                label: Some(label),
                layout: Some(&pipeline_layout),
                vertex: wgpu::VertexState {
                    module: &shader,
                    entry_point: Some("vs_edge"),
                    compilation_options: Default::default(),
                    buffers: &[wgpu::VertexBufferLayout {
                        array_stride: std::mem::size_of::<EdgeInstance>() as u64,
                        step_mode: wgpu::VertexStepMode::Instance,
                        attributes: &wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3],
                    }],
                },
                fragment: Some(wgpu::FragmentState {
                    module: &shader,
                    entry_point: Some("fs_edge"),
                    compilation_options: Default::default(),
                    targets: &[color_target(Some(ALPHA_BLEND))],
                }),
                primitive: wgpu::PrimitiveState {
                    topology: wgpu::PrimitiveTopology::TriangleList,
                    front_face: wgpu::FrontFace::Ccw,
                    cull_mode: None,
                    ..Default::default()
                },
                depth_stencil: Some(wgpu::DepthStencilState {
                    format: DEPTH_FORMAT,
                    // Edges never write depth (they must not occlude faces —
                    // the CADmaterials depthWrite:false behavior).
                    depth_write_enabled: Some(false),
                    depth_compare: Some(depth_compare),
                    stencil: Default::default(),
                    bias: Default::default(),
                }),
                multisample,
                multiview_mask: None,
                cache: None,
            })
        };
        // Visible edges pass the depth test; the hidden pass draws only where
        // the edge is BEHIND geometry (dimmed, not dropped — R17).
        let edge_visible_pipeline = edge_pipeline("edges", wgpu::CompareFunction::LessEqual);
        let edge_hidden_pipeline = edge_pipeline("edges-hidden", wgpu::CompareFunction::Greater);

        let point_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("points"),
            layout: Some(&pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: Some("vs_point"),
                compilation_options: Default::default(),
                buffers: &[wgpu::VertexBufferLayout {
                    array_stride: std::mem::size_of::<PointInstance>() as u64,
                    step_mode: wgpu::VertexStepMode::Instance,
                    attributes: &wgpu::vertex_attr_array![0 => Float32x3],
                }],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: Some("fs_point"),
                compilation_options: Default::default(),
                targets: &[color_target(Some(ALPHA_BLEND))],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::TriangleList,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: None,
                ..Default::default()
            },
            depth_stencil: Some(wgpu::DepthStencilState {
                format: DEPTH_FORMAT,
                depth_write_enabled: Some(false),
                depth_compare: Some(wgpu::CompareFunction::LessEqual),
                stencil: Default::default(),
                bias: Default::default(),
            }),
            multisample,
            multiview_mask: None,
            cache: None,
        });

        // Overlay-widget pipelines. Both reuse the globals + style
        // pipeline layout; tris carry per-vertex color+normal, lines carry
        // per-instance p0/p1/color. They draw in a depth-cleared pass over the
        // solids so widgets read on top.
        let overlay_tri_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("overlay-tri"),
            layout: Some(&pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: Some("vs_overlay_tri"),
                compilation_options: Default::default(),
                buffers: &[wgpu::VertexBufferLayout {
                    array_stride: std::mem::size_of::<OverlayTriVertex>() as u64,
                    step_mode: wgpu::VertexStepMode::Vertex,
                    attributes: &wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3, 2 => Float32x4],
                }],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: Some("fs_overlay_tri"),
                compilation_options: Default::default(),
                targets: &[color_target(Some(ALPHA_BLEND))],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::TriangleList,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: None,
                ..Default::default()
            },
            depth_stencil: Some(wgpu::DepthStencilState {
                format: DEPTH_FORMAT,
                depth_write_enabled: Some(true),
                depth_compare: Some(wgpu::CompareFunction::LessEqual),
                stencil: Default::default(),
                bias: Default::default(),
            }),
            multisample,
            multiview_mask: None,
            cache: None,
        });
        let overlay_line_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
            label: Some("overlay-line"),
            layout: Some(&pipeline_layout),
            vertex: wgpu::VertexState {
                module: &shader,
                entry_point: Some("vs_overlay_line"),
                compilation_options: Default::default(),
                buffers: &[wgpu::VertexBufferLayout {
                    array_stride: std::mem::size_of::<OverlayLineInstance>() as u64,
                    step_mode: wgpu::VertexStepMode::Instance,
                    attributes: &wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3, 2 => Float32x4],
                }],
            },
            fragment: Some(wgpu::FragmentState {
                module: &shader,
                entry_point: Some("fs_overlay_line"),
                compilation_options: Default::default(),
                targets: &[color_target(Some(ALPHA_BLEND))],
            }),
            primitive: wgpu::PrimitiveState {
                topology: wgpu::PrimitiveTopology::TriangleList,
                front_face: wgpu::FrontFace::Ccw,
                cull_mode: None,
                ..Default::default()
            },
            depth_stencil: Some(wgpu::DepthStencilState {
                format: DEPTH_FORMAT,
                depth_write_enabled: Some(false),
                depth_compare: Some(wgpu::CompareFunction::LessEqual),
                stencil: Default::default(),
                bias: Default::default(),
            }),
            multisample,
            multiview_mask: None,
            cache: None,
        });

        // A second globals buffer/bind for the ViewCube pass (its mini-camera).
        let vc_globals_buf = device.create_buffer(&wgpu::BufferDescriptor {
            label: Some("viewcube globals"),
            size: std::mem::size_of::<Globals>() as u64,
            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
            mapped_at_creation: false,
        });
        let vc_globals_bind = device.create_bind_group(&wgpu::BindGroupDescriptor {
            label: Some("viewcube globals"),
            layout: &globals_layout,
            entries: &[wgpu::BindGroupEntry {
                binding: 0,
                resource: vc_globals_buf.as_entire_binding(),
            }],
        });

        let styles = GlobalStyles {
            face_selected: StyleBuf::new(&device, &style_layout, "face-selected"),
            face_hovered: StyleBuf::new(&device, &style_layout, "face-hovered"),
            edge_base: StyleBuf::new(&device, &style_layout, "edge-base"),
            edge_selected: StyleBuf::new(&device, &style_layout, "edge-selected"),
            edge_hovered: StyleBuf::new(&device, &style_layout, "edge-hovered"),
            edge_hidden: StyleBuf::new(&device, &style_layout, "edge-hidden"),
            boundary: StyleBuf::new(&device, &style_layout, "boundary"),
            point_base: StyleBuf::new(&device, &style_layout, "point-base"),
            point_selected: StyleBuf::new(&device, &style_layout, "point-selected"),
            point_hovered: StyleBuf::new(&device, &style_layout, "point-hovered"),
            axis_x: StyleBuf::new(&device, &style_layout, "axis-x"),
            axis_y: StyleBuf::new(&device, &style_layout, "axis-y"),
            axis_z: StyleBuf::new(&device, &style_layout, "axis-z"),
            overlay_line: StyleBuf::new(&device, &style_layout, "overlay-line"),
        };

        Self {
            device,
            queue,
            format,
            globals_buf,
            globals_bind,
            style_layout,
            mesh_pipeline,
            wire_pipeline,
            edge_visible_pipeline,
            edge_hidden_pipeline,
            point_pipeline,
            overlay_tri_pipeline,
            overlay_line_pipeline,
            vc_globals_buf,
            vc_globals_bind,
            styles,
            targets: None,
        }
    }
}