Added a support for loading a png file into a buffer (#823)

This CL adds the `FILE` parameter to `BUFFER` commands. This allows loading file data into the buffer. Currently only PNG data is supported.

3 files changed, 49 insertions, 0 deletions

diff --git a/samples/amber.cc b/samples/amber.cc
index 221da50..31e66f9 100644
--- a/samples/amber.cc
+++ b/samples/amber.cc
@@ -324,10 +324,29 @@ class SampleDelegate : public amber::Delegate {
     return timestamp::SampleGetTimestampNs();
   }
 
+  void SetScriptPath(std::string path) { path_ = path; }
+
+  amber::Result LoadBufferData(const std::string file_name,
+                               amber::BufferInfo* buffer) const override {
+#if AMBER_ENABLE_LODEPNG
+    // Try to load as png first.
+    amber::Result r = png::LoadPNG(path_ + file_name, &buffer->width,
+                                   &buffer->height, &buffer->values);
+
+    if (r.IsSuccess())
+      return r;
+#endif  // AMBER_ENABLE_LODEPNG
+
+    // TODO(asuonpaa): Try to load a binary format.
+
+    return amber::Result("Failed to load buffer data " + file_name);
+  }
+
  private:
   bool log_graphics_calls_ = false;
   bool log_graphics_calls_time_ = false;
   bool log_execute_calls_ = false;
+  std::string path_ = "";
 };
 
 std::string disassemble(const std::string& env,
@@ -531,6 +550,9 @@ int main(int argc, const char** argv) {
     const auto* recipe = recipe_data_elem.recipe.get();
     const auto& file = recipe_data_elem.file;
 
+    // Parse file path and set it for delegate to use when loading buffer data.
+    delegate.SetScriptPath(file.substr(0, file.find_last_of("/\\") + 1));
+
     amber::Amber am;
     result = am.Execute(recipe, &amber_options);
     if (!result.IsSuccess()) {
diff --git a/samples/png.cc b/samples/png.cc
index 93e2279..3dbf4fd 100644
--- a/samples/png.cc
+++ b/samples/png.cc
@@ -81,4 +81,23 @@ amber::Result ConvertToPNG(uint32_t width,
   return {};
 }
 
+amber::Result LoadPNG(const std::string file_name,
+                      uint32_t* width,
+                      uint32_t* height,
+                      std::vector<amber::Value>* values) {
+  std::vector<uint8_t> decoded_buffer;
+  if (lodepng::decode(decoded_buffer, *width, *height, file_name,
+                      LodePNGColorType::LCT_RGBA, 8) != 0) {
+    return amber::Result("lodepng::decode() returned non-zero");
+  }
+
+  for (auto d : decoded_buffer) {
+    amber::Value v;
+    v.SetIntValue(d);
+    values->push_back(v);
+  }
+
+  return {};
+}
+
 }  // namespace png
diff --git a/samples/png.h b/samples/png.h
index 74802e7..b08d74d 100644
--- a/samples/png.h
+++ b/samples/png.h
@@ -31,6 +31,14 @@ amber::Result ConvertToPNG(uint32_t width,
                            const std::vector<amber::Value>& values,
                            std::vector<uint8_t>* buffer);
 
+/// Loads a PNG image from |file_name|. Image dimensions of the loaded file are
+/// stored into |width| and |height|, and the image data is stored in a one
+/// byte per data element format into |values|.
+amber::Result LoadPNG(const std::string file_name,
+                      uint32_t* width,
+                      uint32_t* height,
+                      std::vector<amber::Value>* values);
+
 }  // namespace png
 
 #endif  // SAMPLES_PNG_H_