Add Rgb, Image (#3)

Author: karnkaul

tray/CMakeLists.txt

@@ -1,6 +1,15 @@
 add_executable(${PROJECT_NAME})
-target_sources(${PROJECT_NAME} PRIVATE src/main.cpp)
 target_include_directories(${PROJECT_NAME} PRIVATE src)
+target_sources(${PROJECT_NAME} PRIVATE
+  src/tray/image.cpp
+  src/tray/image.hpp
+  src/tray/io.cpp
+  src/tray/io.hpp
+  src/tray/rgb.hpp
+  src/tray/vec.hpp
+
+  src/main.cpp
+)
 
 if(CMAKE_CXX_COMPILER_ID STREQUAL Clang OR CMAKE_CXX_COMPILER_ID STREQUAL GNU)
   target_compile_options(${PROJECT_NAME} PRIVATE

tray/src/main.cpp

@@ -1,46 +1,23 @@
+#include <tray/image.hpp>
+#include <tray/io.hpp>
 #include <tray/vec.hpp>
-#include <array>
-#include <cassert>
 #include <iostream>
-#include <ostream>
 #include <span>
 
 using namespace tray;
 
-namespace {
-struct Rgb : Vec<std::uint8_t, 3> {};
-
-struct ImageData {
-	std::span<Rgb const> data{};
-	uvec2 extent{};
-};
-
-std::ostream& operator<<(std::ostream& out, ImageData const& image) {
-	assert(image.data.size() == image.extent.x() * image.extent.y());
-	// write header
-	out << "P3\n" << image.extent.x() << ' ' << image.extent.y() << "\n255\n";
-	// write each row
-	for (std::uint32_t row = 0; row < image.extent.y(); ++row) {
-		// write each column
-		for (std::uint32_t col = 0; col < image.extent.x(); ++col) {
-			// compute index
-			auto const index = row * image.extent.x() + col;
-			// obtain corresponding Rgb
-			auto const& rgb = image.data[index];
-			// write out each channel
-			for (auto const channel : rgb.values) { out << static_cast<int>(channel) << ' '; }
+int main() {
+	static constexpr auto extent = uvec2{400U, 300U};
+	auto image = Image{extent};
+	for (std::uint32_t row = 0; row < image.extent().y(); ++row) {
+		auto const ratio = static_cast<float>(row) / static_cast<float>(image.extent().y());
+		auto const tint = ratio * static_cast<float>(0xff);
+		for (std::uint32_t col = 0; col < image.extent().x(); ++col) {
+			auto& rgb = image[{row, col}];
+			rgb.x() = 0xff;
+			rgb.y() = static_cast<std::uint8_t>(tint);
 		}
-		out << '\n';
 	}
-	return out;
-}
-} // namespace
 
-int main() {
-	static constexpr auto extent = uvec2{40U, 30U};
-	static constexpr auto white_v = Rgb{0xff, 0xff, 0xff};
-	auto buffer = std::array<Rgb, extent.x() * extent.y()>{};
-	std::fill_n(buffer.data(), buffer.size(), white_v);
-	auto const image_data = ImageData{.data = buffer, .extent = extent};
-	std::cout << image_data;
+	io::write(image, "test.ppm");
 }

tray/src/tray/image.cpp

@@ -0,0 +1,18 @@
+#include <tray/image.hpp>
+#include <cassert>
+#include <utility>
+
+namespace tray {
+void Image::resize(uvec2 extent) {
+	m_data.resize(extent.x() * extent.y());
+	m_extent = extent;
+}
+
+Rgb const& Image::operator[](Index2D i) const {
+	auto const index = i.index(m_extent);
+	assert(index < m_data.size());
+	return m_data[index];
+}
+
+Rgb& Image::operator[](Index2D i) { return const_cast<Rgb&>(std::as_const(*this)[i]); }
+} // namespace tray

tray/src/tray/image.hpp

@@ -0,0 +1,29 @@
+#pragma once
+#include <tray/rgb.hpp>
+#include <vector>
+
+namespace tray {
+struct Index2D {
+	std::uint32_t row{};
+	std::uint32_t col{};
+
+	constexpr std::size_t index(uvec2 const extent) { return row * extent.x() + col; }
+};
+
+class Image {
+  public:
+	Image() = default;
+	Image(uvec2 extent) { resize(extent); }
+
+	void resize(uvec2 extent);
+
+	Rgb const& operator[](Index2D i) const;
+	Rgb& operator[](Index2D i);
+
+	uvec2 extent() const { return m_extent; }
+
+  private:
+	std::vector<Rgb> m_data{};
+	uvec2 m_extent{};
+};
+} // namespace tray

tray/src/tray/io.cpp

@@ -0,0 +1,26 @@
+#include <tray/io.hpp>
+#include <fstream>
+
+namespace tray {
+std::ostream& operator<<(std::ostream& out, Image const& image) {
+	// write header
+	out << "P3\n" << image.extent().x() << ' ' << image.extent().y() << "\n255\n";
+	// write each row
+	for (std::uint32_t row = 0; row < image.extent().y(); ++row) {
+		// write each column
+		for (std::uint32_t col = 0; col < image.extent().x(); ++col) {
+			// obtain corresponding Rgb
+			auto const& rgb = image[{row, col}];
+			// write out each channel
+			for (auto const channel : rgb.values) { out << static_cast<int>(channel) << ' '; }
+		}
+		out << '\n';
+	}
+	return out;
+}
+
+bool io::write(Image const& image, char const* path) {
+	if (auto file = std::ofstream(path)) { return static_cast<bool>(file << image); }
+	return false;
+}
+} // namespace tray

tray/src/tray/io.hpp

@@ -0,0 +1,11 @@
+#pragma once
+#include <tray/image.hpp>
+#include <ostream>
+
+namespace tray {
+std::ostream& operator<<(std::ostream& out, Image const& image);
+
+namespace io {
+bool write(Image const& image, char const* path);
+}
+} // namespace tray

tray/src/tray/rgb.hpp

@@ -0,0 +1,6 @@
+#pragma once
+#include <tray/vec.hpp>
+
+namespace tray {
+struct Rgb : Vec<std::uint8_t, 3> {};
+} // namespace tray