summaryrefslogtreecommitdiff
path: root/src/tests/offscreen_render_target.h
blob: 10c12aa152372024a24e9a38aaefdd88916a0228 (plain)
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
// This file is part of the 64k demo project.
// It provides offscreen rendering without windows (headless testing).
// Enables pixel readback for frame validation in tests.

#pragma once

#include "platform/platform.h"
#include <cstdint>
#include <vector>

// Offscreen render target for headless GPU testing
// Creates a texture that can be rendered to and read back
class OffscreenRenderTarget {
 public:
  // Create an offscreen render target with specified dimensions
  OffscreenRenderTarget(
      WGPUInstance instance, WGPUDevice device, int width, int height,
      WGPUTextureFormat format = WGPUTextureFormat_BGRA8Unorm);
  ~OffscreenRenderTarget();

  // Accessors
  WGPUTexture texture() const {
    return texture_;
  }
  WGPUTextureView view() const {
    return view_;
  }
  int width() const {
    return width_;
  }
  int height() const {
    return height_;
  }
  WGPUTextureFormat format() const {
    return format_;
  }

  // Read pixels from the render target
  // Returns BGRA8 pixel data (width * height * 4 bytes)
  std::vector<uint8_t> read_pixels();

 private:
  WGPUInstance instance_;
  WGPUDevice device_;
  WGPUTexture texture_;
  WGPUTextureView view_;
  int width_;
  int height_;
  WGPUTextureFormat format_;

  // Helper: Create staging buffer for readback
  WGPUBuffer create_staging_buffer();

  // Callback state for async buffer mapping
  struct MapState {
    bool done = false;
    WGPUMapAsyncStatus status = WGPUMapAsyncStatus_Unknown;
  };

  static void map_callback(WGPUMapAsyncStatus status, void* userdata);
};