fix z value discontinuity on chunk boundaries

2 files changed, 12 insertions, 8 deletions

diff --git a/src/camera-offset.cpp b/src/camera-offset.cpp
index 335a9b65..7c5be7f3 100644
--- a/src/camera-offset.cpp
+++ b/src/camera-offset.cpp
@@ -6,18 +6,22 @@ namespace floormat {
 
 static_assert(sizeof(short) == 2);
 
-with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, short x, short y) :
+with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, chunk_coords c, chunk_coords first, chunk_coords last) :
     _shader{shader},
-    _offset{shader.camera_offset()}
+    _camera{shader.camera_offset()},
+    _depth{shader.depth_offset()}
 {
     constexpr auto chunk_size = TILE_MAX_DIM20d*dTILE_SIZE;
-    const auto offset = _offset + tile_shader::project(Vector3d(x, y, 0) * chunk_size);
-    _shader.set_camera_offset(offset);
+    const auto offset = _camera + tile_shader::project(Vector3d(c.x, c.y, 0) * chunk_size);
+    const auto len_x = (float)(last.x - first.x), cx = (float)(c.x - first.x), cy = (float)(c.y - first.y);
+    const float depth_offset = _depth + shader.depth_tile_size*(cy*TILE_MAX_DIM*len_x*TILE_MAX_DIM + cx*TILE_MAX_DIM);
+
+    _shader.set_camera_offset(offset, depth_offset);
 }
 
 with_shifted_camera_offset::~with_shifted_camera_offset()
 {
-    _shader.set_camera_offset(_offset);
+    _shader.set_camera_offset(_camera, _depth);
 }
 
 } // namespace floormat
diff --git a/src/camera-offset.hpp b/src/camera-offset.hpp
index 0a44ee30..ef098694 100644
--- a/src/camera-offset.hpp
+++ b/src/camera-offset.hpp
@@ -9,12 +9,12 @@ struct tile_shader;
 
 struct with_shifted_camera_offset final
 {
-    explicit with_shifted_camera_offset(tile_shader& shader, short x, short y);
-    explicit with_shifted_camera_offset(tile_shader& shader, chunk_coords c) : with_shifted_camera_offset(shader, c.x, c.y) {}
+    explicit with_shifted_camera_offset(tile_shader& shader, chunk_coords c, chunk_coords first, chunk_coords last);
     ~with_shifted_camera_offset();
 private:
     tile_shader& _shader; // NOLINT
-    Vector2d _offset;
+    Vector2d _camera;
+    float _depth;
 };
 
 } // namespace floormat