1 files changed, 70 insertions, 0 deletions
diff --git a/big-atlas-tool/big-atlas.cpp b/big-atlas-tool/big-atlas.cpp
new file mode 100644
index 00000000..4bfe5eea
--- /dev/null
+++ b/big-atlas-tool/big-atlas.cpp
@@ -0,0 +1,70 @@
+#undef NDEBUG
+
+#include "big-atlas.hpp"
+#include <cassert>
+#include <filesystem>
+#include <Corrade/Utility/DebugStl.h>
+#include <opencv2/imgproc/imgproc.hpp>
+#include <opencv2/imgcodecs/imgcodecs.hpp>
+
+using Corrade::Utility::Error;
+
+std::vector<big_atlas_frame> big_atlas_builder::add_atlas(const std::filesystem::path& filename)
+{
+    std::vector<big_atlas_frame> ret;
+    cv::Mat mat = cv::imread(filename.string(), cv::IMREAD_UNCHANGED);
+    if (mat.empty() || (mat.type() != CV_8UC4 && mat.type() != CV_8UC3))
+    {
+        Error{} << "failed to load" << filename << "as RGBA32 image";
+        return {};
+    }
+    if (mat.type() == CV_8UC3) {
+        cv::Mat mat2;
+        cv::cvtColor(mat, mat2, cv::COLOR_RGB2RGBA);
+        mat = mat2.clone();
+    }
+
+    Error{} << "file" << filename;
+
+    assert(mat.cols % TILE_SIZE[0] == 0 && mat.rows % TILE_SIZE[1] == 0);
+
+    for (int y = 0; y + TILE_SIZE[1] <= mat.rows; y += TILE_SIZE[1])
+        for (int x = 0; x + TILE_SIZE[0] <= mat.cols; x += TILE_SIZE[0])
+        {
+            cv::Rect roi { x, y, TILE_SIZE[0], TILE_SIZE[1] };
+            auto frame = add_frame(mat(roi));
+            ret.push_back(frame);
+        }
+
+    return ret;
+}
+
+big_atlas_frame& big_atlas_builder::add_frame(const cv::Mat4b& frame)
+{
+    auto [row, xpos, ypos] = advance();
+    row.frames.push_back({ frame, { xpos, ypos } });
+    return row.frames.back();
+}
+
+std::tuple<big_atlas_row&, int, int> big_atlas_builder::advance()
+{
+    auto& row = _rows.back();
+    const int xpos_ = row.xpos;
+    row.xpos += TILE_SIZE[0];
+
+    if (row.xpos + TILE_SIZE[0] > MAX_TEXTURE_SIZE[0])
+    {
+        ypos += TILE_SIZE[1];
+        assert(ypos < MAX_TEXTURE_SIZE[1]);
+        _rows.emplace_back();
+        auto& row = _rows.back();
+        row.ypos = ypos;
+        row.xpos = 0;
+        return { row, 0, row.ypos };
+    }
+    else {
+        maxx = std::max(maxx, row.xpos);
+        maxy = row.ypos + TILE_SIZE[1];
+        return { row, xpos_, row.ypos };
+    }
+}