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

// Copyright 2015 The Gfx-rs Developers.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Render stream extension. Stream is something you can send batches to.
//! It includes a renderer and an output, stored by constrained types.


use device::{Device, InstanceCount, Resources, VertexCount};
use device::draw::CommandBuffer;
use device::target::{ClearData, Mask, Mirror, Rect};
use render::{DrawError, Renderer, RenderFactory};
use render::batch::Batch;
use render::target::Output;

//TODO: when `Stream` gets adopted, we can remove these methods:
//  - Renderer::draw(...)
//  - Renderer::draw_instanced(...)
// in favor of bare `Renderer::draw_all` (renamed), since most
// of the usage will go through `Stream`, which already has this.

/// Render stream abstraction.
pub trait Stream<R: Resources> {
    /// Command buffer type to constraint the `Renderer`.
    type CommandBuffer: CommandBuffer<R>;
    /// Constrained `Output` type.
    type Output: Output<R>;

    /// Get the output only.
    fn get_output(&self) -> &Self::Output;

    /// Access both of the stream components.
    fn access(&mut self) -> (&mut Renderer<R, Self::CommandBuffer>, &Self::Output);

    /// Get width/height aspect, needed for projections.
    fn get_aspect_ratio(&self) -> f32 {
        let (w, h) = self.get_output().get_size();
        w as f32 / h as f32
    }

    /// Clear the canvas.
    fn clear(&mut self, data: ClearData) {
        let (ren, out) = self.access();
        let mask = out.get_mask();
        ren.clear(data, mask, out);
    }

    /// Blit on this stream from another `Output`.
    fn blit_on<I: Output<R>>(&mut self,
               source: &I, source_rect: Rect, dest_rect: Rect,
               mirror: Mirror, mask: Mask) {
        let (ren, out) = self.access();
        ren.blit(source, source_rect, out, dest_rect, mirror, mask);
    }

    /// Blit this stream to another `Output`.
    fn blit_to<O: Output<R>>(&mut self,
               destination: &O, dest_rect: Rect, source_rect: Rect,
               mirror: Mirror, mask: Mask) {
        let (ren, out) = self.access();
        ren.blit(out, source_rect, destination, dest_rect, mirror, mask);
    }

    /// Draw a simple `Batch`.
    fn draw<B: Batch<R>>(&mut self, batch: &B) 
            -> Result<(), DrawError<B::Error>> {
        let (ren, out) = self.access();
        ren.draw(batch, out)
    }

    /// Draw an instanced `Batch`.
    fn draw_instanced<B: Batch<R>>(&mut self, batch: &B,
                      count: InstanceCount, base: VertexCount)
                      -> Result<(), DrawError<B::Error>> {
        let (ren, out) = self.access();
        ren.draw_instanced(batch, count, base, out)
    }

    /// Execute everything and clear the command buffer.
    fn flush<D>(&mut self, device: &mut D) where
        D: Device<Resources = R, CommandBuffer = Self::CommandBuffer>,
    {
        let (ren, _) = self.access();
        device.submit(ren.as_buffer());
        ren.reset();
    }
}

impl<'a, R: Resources, C: CommandBuffer<R>, O: Output<R>>
Stream<R> for (&'a mut Renderer<R, C>, &'a O) {
    type CommandBuffer = C;
    type Output = O;

    fn get_output(&self) -> &O {
        &self.1
    }

    fn access(&mut self) -> (&mut Renderer<R, C>, &O) {
        (&mut self.0, &self.1)
    }
}

/// A stream that owns its components.
pub struct OwnedStream<
    R: Resources,
    C: CommandBuffer<R>,
    O: Output<R>
>(pub Renderer<R, C>, pub O);

impl<R: Resources, C: CommandBuffer<R>, O: Output<R>>
Stream<R> for OwnedStream<R, C, O> {
    type CommandBuffer = C;
    type Output = O;

    fn get_output(&self) -> &O {
        &self.1
    }

    fn access(&mut self) -> (&mut Renderer<R, C>, &O) {
        (&mut self.0, &self.1)
    }
}

/// A render factory extension that allows creating streams with new renderers.
pub trait StreamFactory<R: Resources, C: CommandBuffer<R>>: RenderFactory<R, C> {
    /// Create a new stream from a given output.
    fn create_stream<O: Output<R>>(&mut self, output: O) -> OwnedStream<R, C, O> {
        OwnedStream(self.create_renderer(), output)
    }
}

impl<R: Resources, C: CommandBuffer<R>>
StreamFactory<R, C> for RenderFactory<R, C> {}