a

2 files changed, 45 insertions, 0 deletions

diff --git a/src/camera-offset.cpp b/src/camera-offset.cpp
new file mode 100644
index 00000000..47cb690d
--- /dev/null
+++ b/src/camera-offset.cpp
@@ -0,0 +1,27 @@
+#include "camera-offset.hpp"
+#include "shaders/tile-shader.hpp"
+
+namespace floormat {
+
+with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, std::int32_t x, std::int32_t y) :
+      with_shifted_camera_offset{shader, chunk_coords{std::int16_t(x), std::int16_t(y)}}
+{
+    ASSERT(std::abs(x) < (1 << 15) && std::abs(y) < (1 << 15));
+}
+
+with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, const chunk_coords c) :
+    s{shader},
+    orig_offset(shader.camera_offset())
+{
+    const auto offset = tile_shader::project({float(c.x)*TILE_MAX_DIM*TILE_SIZE[0],
+                                              float(c.y)*TILE_MAX_DIM*TILE_SIZE[1],
+                                              0});
+    s.set_camera_offset(orig_offset + offset);
+}
+
+with_shifted_camera_offset::~with_shifted_camera_offset()
+{
+    s.set_camera_offset(orig_offset);
+}
+
+} // namespace floormat
diff --git a/src/camera-offset.hpp b/src/camera-offset.hpp
new file mode 100644
index 00000000..da07cec0
--- /dev/null
+++ b/src/camera-offset.hpp
@@ -0,0 +1,18 @@
+#pragma once
+#include "src/global-coords.hpp"
+
+namespace floormat {
+
+struct tile_shader;
+
+struct with_shifted_camera_offset final
+{
+    explicit with_shifted_camera_offset(tile_shader& shader, std::int32_t, std::int32_t);
+    explicit with_shifted_camera_offset(tile_shader& shader, chunk_coords c);
+    ~with_shifted_camera_offset();
+private:
+    tile_shader& s; // NOLINT
+    Vector2 orig_offset;
+};
+
+} // namespace floormat