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.

12 files changed, 190 insertions, 7 deletions

diff --git a/docs/amber_script.md b/docs/amber_script.md
index 1191d60..56430f7 100644
--- a/docs/amber_script.md
+++ b/docs/amber_script.md
@@ -156,6 +156,11 @@ BUFFER {name} DATA_TYPE {type} {STD140 | STD430} WIDTH {w} HEIGHT {h} \
 # The buffer will be sized based on the `RENDER_SIZE` of the `PIPELINE`.
 BUFFER {name} FORMAT {format_string} \
     [ MIP_LEVELS _mip_levels_ (default 1) ]
+
+# Load buffer data from a PNG image with file name specified by `FILE`.
+# The file path is relative to the script file being run. Format specified
+# by `FORMAT` must match the image format.
+BUFFER {name} FORMAT {format_string} FILE {file_name.png}
 ```
 
 #### Images
diff --git a/include/amber/amber.h b/include/amber/amber.h
index 1fffd38..b665de2 100644
--- a/include/amber/amber.h
+++ b/include/amber/amber.h
@@ -85,6 +85,9 @@ class Delegate {
   virtual uint64_t GetTimestampNs() const = 0;
   /// Tells whether to log each test as it's executed
   virtual bool LogExecuteCalls() const = 0;
+  /// Loads buffer data from a file
+  virtual amber::Result LoadBufferData(const std::string file_name,
+                                       amber::BufferInfo* buffer) const = 0;
 };
 
 /// Stores configuration options for Amber.
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_
diff --git a/src/amberscript/parser.cc b/src/amberscript/parser.cc
index 8157476..60292b0 100644
--- a/src/amberscript/parser.cc
+++ b/src/amberscript/parser.cc
@@ -1224,14 +1224,27 @@ Result Parser::ParseBuffer() {
     script_->RegisterFormat(std::move(fmt));
 
     token = tokenizer_->PeekNextToken();
-    if (token->IsIdentifier() && token->AsString() == "MIP_LEVELS") {
-      tokenizer_->NextToken();
-      token = tokenizer_->NextToken();
+    while (token->IsIdentifier()) {
+      if (token->AsString() == "MIP_LEVELS") {
+        tokenizer_->NextToken();
+        token = tokenizer_->NextToken();
 
-      if (!token->IsInteger())
-        return Result("invalid value for MIP_LEVELS");
+        if (!token->IsInteger())
+          return Result("invalid value for MIP_LEVELS");
 
-      buffer->SetMipLevels(token->AsUint32());
+        buffer->SetMipLevels(token->AsUint32());
+      } else if (token->AsString() == "FILE") {
+        tokenizer_->NextToken();
+        token = tokenizer_->NextToken();
+
+        if (!token->IsIdentifier())
+          return Result("invalid value for FILE");
+
+        buffer->SetDataFile(token->AsString());
+      } else {
+        break;
+      }
+      token = tokenizer_->PeekNextToken();
     }
   } else {
     return Result("unknown BUFFER command provided: " + cmd);
diff --git a/src/amberscript/parser_buffer_test.cc b/src/amberscript/parser_buffer_test.cc
index dcbd982..d2f1eb1 100644
--- a/src/amberscript/parser_buffer_test.cc
+++ b/src/amberscript/parser_buffer_test.cc
@@ -1067,5 +1067,30 @@ TEST_F(AmberScriptParserTest, BufferMissingMipLevels) {
   EXPECT_EQ("1: invalid value for MIP_LEVELS", r.Error());
 }
 
+TEST_F(AmberScriptParserTest, BufferMissingDataFile) {
+  std::string in = "BUFFER my_buffer FORMAT R8G8B8A8_UNORM FILE";
+
+  Parser parser;
+  Result r = parser.Parse(in);
+  ASSERT_FALSE(r.IsSuccess());
+
+  EXPECT_EQ("1: invalid value for FILE", r.Error());
+}
+
+TEST_F(AmberScriptParserTest, BufferDataFile) {
+  std::string in = "BUFFER my_buffer FORMAT R8G8B8A8_UNORM FILE foo.png";
+
+  Parser parser;
+  Result r = parser.Parse(in);
+  ASSERT_TRUE(r.IsSuccess()) << r.Error();
+
+  auto script = parser.GetScript();
+  const auto& buffers = script->GetBuffers();
+  ASSERT_EQ(1U, buffers.size());
+
+  ASSERT_TRUE(buffers[0] != nullptr);
+  EXPECT_EQ("foo.png", buffers[0]->GetDataFile());
+}
+
 }  // namespace amberscript
 }  // namespace amber
diff --git a/src/buffer.h b/src/buffer.h
index d867a5a..9d6f3d6 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -196,6 +196,12 @@ class Buffer {
   /// Returns the number of mip levels.
   uint32_t GetMipLevels() { return mip_levels_; }
 
+  /// Sets the file name for loading data into the buffer.
+  void SetDataFile(std::string data_file) { data_file_ = data_file; }
+
+  /// Returns the file name used to load buffer data from.
+  std::string GetDataFile() { return data_file_; }
+
   /// Returns a pointer to the internal storage of the buffer.
   std::vector<uint8_t>* ValuePtr() { return &bytes_; }
   /// Returns a pointer to the internal storage of the buffer.
@@ -252,6 +258,7 @@ class Buffer {
   Format* format_ = nullptr;
   Sampler* sampler_ = nullptr;
   ImageDimension image_dim_ = ImageDimension::kUnknown;
+  std::string data_file_;
 };
 
 }  // namespace amber
diff --git a/src/executor.cc b/src/executor.cc
index 0d428e9..5ff76d2 100644
--- a/src/executor.cc
+++ b/src/executor.cc
@@ -88,6 +88,21 @@ Result Executor::Execute(Engine* engine,
 
   Engine::Debugger* debugger = nullptr;
 
+  // Load data to buffers
+  for (const auto& buf : script->GetBuffers()) {
+    if (buf->GetDataFile().empty())
+      continue;
+
+    BufferInfo info;
+    Result r = options->delegate->LoadBufferData(buf->GetDataFile(), &info);
+    if (!r.IsSuccess())
+      return r;
+
+    buf->SetData(info.values);
+    buf->SetWidth(info.width);
+    buf->SetHeight(info.height);
+  }
+
   // Process Commands
   for (const auto& cmd : script->GetCommands()) {
     if (options->delegate && options->delegate->LogExecuteCalls()) {
diff --git a/tests/cases/draw_png_texture.amber b/tests/cases/draw_png_texture.amber
new file mode 100644
index 0000000..c7b9885
--- /dev/null
+++ b/tests/cases/draw_png_texture.amber
@@ -0,0 +1,66 @@
+#!amber
+# Copyright 2020 The Amber Authors.
+#
+# 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
+#
+#     https://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.
+
+SHADER vertex vert_shader_tex GLSL
+#version 430
+layout(location = 0) in vec4 position;
+layout(location = 1) in vec2 texcoords_in;
+layout(location = 0) out vec2 texcoords_out;
+void main() {
+  gl_Position = position;
+  texcoords_out = texcoords_in;
+}
+END
+
+SHADER fragment frag_shader_tex GLSL
+#version 430
+layout(location = 0) in vec2 texcoords_in;
+layout(location = 0) out vec4 color_out;
+uniform layout(set=0, binding=0) sampler2D tex_sampler;
+void main() {
+  color_out = texture(tex_sampler, texcoords_in);
+}
+END
+
+BUFFER texture FORMAT R8G8B8A8_UNORM FILE texture.png
+BUFFER framebuffer FORMAT B8G8R8A8_UNORM
+SAMPLER sampler
+BUFFER position DATA_TYPE vec2<float> DATA
+-0.75 -0.75
+ 0.75 -0.75
+ 0.75  0.75
+-0.75  0.75
+END
+BUFFER texcoords DATA_TYPE vec2<float> DATA
+0.0 0.0
+1.0 0.0
+1.0 1.0
+0.0 1.0
+END
+
+PIPELINE graphics pipeline
+  ATTACH vert_shader_tex
+  ATTACH frag_shader_tex
+  BIND BUFFER texture AS combined_image_sampler SAMPLER sampler DESCRIPTOR_SET 0 BINDING 0
+  VERTEX_DATA position LOCATION 0
+  VERTEX_DATA texcoords LOCATION 1
+  FRAMEBUFFER_SIZE 256 256
+  BIND BUFFER framebuffer AS color LOCATION 0
+END
+
+# Draw the texture using a default sampler.
+CLEAR_COLOR pipeline 0 255 0 255
+CLEAR pipeline
+RUN pipeline DRAW_ARRAY AS TRIANGLE_FAN START_IDX 0 COUNT 4
diff --git a/tests/cases/texture.png b/tests/cases/texture.png
new file mode 100644
index 0000000..465bf9a
--- /dev/null
+++ b/tests/cases/texture.png
diff --git a/tests/run_tests.py b/tests/run_tests.py
index b3903cd..6b17f56 100755
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -323,7 +323,7 @@ class TestRunner:
       print("--test-prog-path must point to an executable")
       return 1
 
-    input_file_re = re.compile('^.+[.][amber|vkscript]')
+    input_file_re = re.compile('^.+[\.]amber|vkscript')
     self.test_cases = []
 
     if self.args: