add PaletteAtlasBuilder

src/graphics/core/PaletteAtlasBuilder.cpp

@@ -0,0 +1,26 @@
+#include "PaletteAtlasBuilder.hpp"
+
+#include "../core/Atlas.hpp"
+#include "../core/ImageData.hpp"
+
+PaletteAtlasBuilder::PaletteAtlasBuilder() = default;
+
+void PaletteAtlasBuilder::put(const std::string& name, const glm::vec4& color) {
+    entries[name] = { glm::clamp(color, glm::vec4(0.0f), glm::vec4(1.0f)) };
+}
+
+std::unique_ptr<Atlas> PaletteAtlasBuilder::build() const {
+    AtlasBuilder builder;
+    for (const auto& [name, entry] : entries) {
+        ubyte data[4] {
+            static_cast<ubyte>(entry.color.r * 255),
+            static_cast<ubyte>(entry.color.g * 255),
+            static_cast<ubyte>(entry.color.b * 255),
+            static_cast<ubyte>(entry.color.a * 255),
+        };
+        builder.add(name, std::make_unique<ImageData>(
+            ImageFormat::RGBA8888, 1, 1, data
+        ));
+    }
+    return builder.build(1, true);
+}

src/graphics/core/PaletteAtlasBuilder.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <memory>
+#include <map>
+#include <glm/vec4.hpp>
+
+class Atlas;
+
+class PaletteAtlasBuilder {
+public:
+    struct Entry {
+        glm::vec4 color;
+    };
+
+    PaletteAtlasBuilder();
+
+    void put(const std::string& name, const glm::vec4& color);
+
+    std::unique_ptr<Atlas> build() const;
+private:
+    std::map<std::string, Entry> entries;
+};