Add renderer readback command contract

src/renderer_api/recording_renderer.cpp

@@ -174,6 +174,34 @@ pp::foundation::Status RecordingCommandContext::draw() noexcept
     return pp::foundation::Status::success();
 }
 
+pp::foundation::Status RecordingCommandContext::read_texture(
+    ITexture2D& texture,
+    ReadbackRegion region,
+    IReadbackBuffer& destination) noexcept
+{
+    if (in_render_pass_) {
+        return pp::foundation::Status::invalid_argument("readback must be outside a render pass");
+    }
+
+    const auto desc = texture.desc();
+    const auto bytes = readback_byte_size(desc, region);
+    if (!bytes) {
+        return bytes.status();
+    }
+
+    if (destination.size_bytes() < bytes.value()) {
+        return pp::foundation::Status::out_of_range("readback buffer is too small");
+    }
+
+    push_command(commands_, RecordedRenderCommand {
+        .kind = RecordedRenderCommandKind::read_texture,
+        .texture_desc = desc,
+        .readback_region = region,
+        .readback_bytes = bytes.value(),
+    });
+    return pp::foundation::Status::success();
+}
+
 void RecordingCommandContext::end_render_pass() noexcept
 {
     if (!in_render_pass_) {
@@ -251,6 +279,8 @@ const char* recorded_render_command_kind_name(RecordedRenderCommandKind kind) no
         return "bind_mesh";
     case RecordedRenderCommandKind::draw:
         return "draw";
+    case RecordedRenderCommandKind::read_texture:
+        return "read_texture";
     case RecordedRenderCommandKind::end_render_pass:
         return "end_render_pass";
     case RecordedRenderCommandKind::trace_marker: