1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
use std::ops::Range;

use wgt::{BufferAddress, DynamicOffset, IndexFormat};

use crate::{BindGroup, Buffer, BufferSlice, RenderBundleEncoder, RenderPass, RenderPipeline};

/// Methods shared by [`RenderPass`] and [`RenderBundleEncoder`].
pub trait RenderEncoder<'a> {
    /// Sets the active bind group for a given bind group index. The bind group layout
    /// in the active pipeline when any `draw()` function is called must match the layout of this bind group.
    ///
    /// If the bind group have dynamic offsets, provide them in order of their declaration.
    fn set_bind_group(
        &mut self,
        index: u32,
        bind_group: Option<&'a BindGroup>,
        offsets: &[DynamicOffset],
    );

    /// Sets the active render pipeline.
    ///
    /// Subsequent draw calls will exhibit the behavior defined by `pipeline`.
    fn set_pipeline(&mut self, pipeline: &'a RenderPipeline);

    /// Sets the active index buffer.
    ///
    /// Subsequent calls to [`draw_indexed`](RenderEncoder::draw_indexed) on this [`RenderEncoder`] will
    /// use `buffer` as the source index buffer.
    fn set_index_buffer(&mut self, buffer_slice: BufferSlice<'a>, index_format: IndexFormat);

    /// Assign a vertex buffer to a slot.
    ///
    /// Subsequent calls to [`draw`] and [`draw_indexed`] on this
    /// [`RenderEncoder`] will use `buffer` as one of the source vertex buffers.
    ///
    /// The `slot` refers to the index of the matching descriptor in
    /// [VertexState::buffers](crate::VertexState::buffers).
    ///
    /// [`draw`]: RenderEncoder::draw
    /// [`draw_indexed`]: RenderEncoder::draw_indexed
    fn set_vertex_buffer(&mut self, slot: u32, buffer_slice: BufferSlice<'a>);

    /// Draws primitives from the active vertex buffer(s).
    ///
    /// The active vertex buffers can be set with [`RenderEncoder::set_vertex_buffer`].
    fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>);

    /// Draws indexed primitives using the active index buffer and the active vertex buffers.
    ///
    /// The active index buffer can be set with [`RenderEncoder::set_index_buffer`], while the active
    /// vertex buffers can be set with [`RenderEncoder::set_vertex_buffer`].
    fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>);

    /// Draws primitives from the active vertex buffer(s) based on the contents of the `indirect_buffer`.
    ///
    /// The active vertex buffers can be set with [`RenderEncoder::set_vertex_buffer`].
    ///
    /// The structure expected in `indirect_buffer` must conform to [`DrawIndirectArgs`](crate::util::DrawIndirectArgs).
    fn draw_indirect(&mut self, indirect_buffer: &'a Buffer, indirect_offset: BufferAddress);

    /// Draws indexed primitives using the active index buffer and the active vertex buffers,
    /// based on the contents of the `indirect_buffer`.
    ///
    /// The active index buffer can be set with [`RenderEncoder::set_index_buffer`], while the active
    /// vertex buffers can be set with [`RenderEncoder::set_vertex_buffer`].
    ///
    /// The structure expected in `indirect_buffer` must conform to [`DrawIndexedIndirectArgs`](crate::util::DrawIndexedIndirectArgs).
    fn draw_indexed_indirect(
        &mut self,
        indirect_buffer: &'a Buffer,
        indirect_offset: BufferAddress,
    );

    /// [`wgt::Features::PUSH_CONSTANTS`] must be enabled on the device in order to call this function.
    ///
    /// Set push constant data.
    ///
    /// Offset is measured in bytes, but must be a multiple of [`wgt::PUSH_CONSTANT_ALIGNMENT`].
    ///
    /// Data size must be a multiple of 4 and must be aligned to the 4s, so we take an array of u32.
    /// For example, with an offset of 4 and an array of `[u32; 3]`, that will write to the range
    /// of 4..16.
    ///
    /// For each byte in the range of push constant data written, the union of the stages of all push constant
    /// ranges that covers that byte must be exactly `stages`. There's no good way of explaining this simply,
    /// so here are some examples:
    ///
    /// ```text
    /// For the given ranges:
    /// - 0..4 Vertex
    /// - 4..8 Fragment
    /// ```
    ///
    /// You would need to upload this in two set_push_constants calls. First for the `Vertex` range, second for the `Fragment` range.
    ///
    /// ```text
    /// For the given ranges:
    /// - 0..8  Vertex
    /// - 4..12 Fragment
    /// ```
    ///
    /// You would need to upload this in three set_push_constants calls. First for the `Vertex` only range 0..4, second
    /// for the `Vertex | Fragment` range 4..8, third for the `Fragment` range 8..12.
    fn set_push_constants(&mut self, stages: wgt::ShaderStages, offset: u32, data: &[u8]);
}

impl<'a> RenderEncoder<'a> for RenderPass<'a> {
    #[inline(always)]
    fn set_bind_group(
        &mut self,
        index: u32,
        bind_group: Option<&'a BindGroup>,
        offsets: &[DynamicOffset],
    ) {
        Self::set_bind_group(self, index, bind_group, offsets);
    }

    #[inline(always)]
    fn set_pipeline(&mut self, pipeline: &'a RenderPipeline) {
        Self::set_pipeline(self, pipeline);
    }

    #[inline(always)]
    fn set_index_buffer(&mut self, buffer_slice: BufferSlice<'a>, index_format: IndexFormat) {
        Self::set_index_buffer(self, buffer_slice, index_format);
    }

    #[inline(always)]
    fn set_vertex_buffer(&mut self, slot: u32, buffer_slice: BufferSlice<'a>) {
        Self::set_vertex_buffer(self, slot, buffer_slice);
    }

    #[inline(always)]
    fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>) {
        Self::draw(self, vertices, instances);
    }

    #[inline(always)]
    fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>) {
        Self::draw_indexed(self, indices, base_vertex, instances);
    }

    #[inline(always)]
    fn draw_indirect(&mut self, indirect_buffer: &'a Buffer, indirect_offset: BufferAddress) {
        Self::draw_indirect(self, indirect_buffer, indirect_offset);
    }

    #[inline(always)]
    fn draw_indexed_indirect(
        &mut self,
        indirect_buffer: &'a Buffer,
        indirect_offset: BufferAddress,
    ) {
        Self::draw_indexed_indirect(self, indirect_buffer, indirect_offset);
    }

    #[inline(always)]
    fn set_push_constants(&mut self, stages: wgt::ShaderStages, offset: u32, data: &[u8]) {
        Self::set_push_constants(self, stages, offset, data);
    }
}

impl<'a> RenderEncoder<'a> for RenderBundleEncoder<'a> {
    #[inline(always)]
    fn set_bind_group(
        &mut self,
        index: u32,
        bind_group: Option<&'a BindGroup>,
        offsets: &[DynamicOffset],
    ) {
        Self::set_bind_group(self, index, bind_group, offsets);
    }

    #[inline(always)]
    fn set_pipeline(&mut self, pipeline: &'a RenderPipeline) {
        Self::set_pipeline(self, pipeline);
    }

    #[inline(always)]
    fn set_index_buffer(&mut self, buffer_slice: BufferSlice<'a>, index_format: IndexFormat) {
        Self::set_index_buffer(self, buffer_slice, index_format);
    }

    #[inline(always)]
    fn set_vertex_buffer(&mut self, slot: u32, buffer_slice: BufferSlice<'a>) {
        Self::set_vertex_buffer(self, slot, buffer_slice);
    }

    #[inline(always)]
    fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>) {
        Self::draw(self, vertices, instances);
    }

    #[inline(always)]
    fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>) {
        Self::draw_indexed(self, indices, base_vertex, instances);
    }

    #[inline(always)]
    fn draw_indirect(&mut self, indirect_buffer: &'a Buffer, indirect_offset: BufferAddress) {
        Self::draw_indirect(self, indirect_buffer, indirect_offset);
    }

    #[inline(always)]
    fn draw_indexed_indirect(
        &mut self,
        indirect_buffer: &'a Buffer,
        indirect_offset: BufferAddress,
    ) {
        Self::draw_indexed_indirect(self, indirect_buffer, indirect_offset);
    }

    #[inline(always)]
    fn set_push_constants(&mut self, stages: wgt::ShaderStages, offset: u32, data: &[u8]) {
        Self::set_push_constants(self, stages, offset, data);
    }
}