depth buffer fixes

3 files changed, 29 insertions, 15 deletions

diff --git a/src/camera-offset.cpp b/src/camera-offset.cpp
index 0aab5ea1..de6f584d 100644
--- a/src/camera-offset.cpp
+++ b/src/camera-offset.cpp
@@ -4,25 +4,35 @@
 
 namespace floormat {
 
-with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, chunk_coords_ c, chunk_coords first, chunk_coords last) :
+with_shifted_camera_offset::with_shifted_camera_offset(tile_shader& shader, chunk_coords_ c_, chunk_coords first_, chunk_coords last_) :
     _shader{shader},
     _camera{shader.camera_offset()}
 {
     fm_assert(shader.depth_offset() == 0.f);
 
     constexpr auto chunk_size = TILE_MAX_DIM20d*dTILE_SIZE;
-    const auto offset = _camera + tile_shader::project(Vector3d(c.x, c.y, 0) * chunk_size);
-    first.x -= 8; first.y -= 8; last.x += 8; last.y += 8; // Z levels
-    auto len_x = (float)(last.x - first.x), cx = (float)(c.x - first.x), cy = (float)(c.y - first.y);
-    //cx += c.z; cy += c.z;
-    float depth_offset = shader.depth_tile_size*(cy*TILE_MAX_DIM*len_x*TILE_MAX_DIM + cx*TILE_MAX_DIM);
-    const int z = c.z - chunk_z_min;
-    depth_offset += tile_shader::depth_value(local_coords{z, z});
-
-    // wip
-
-    if (c.z == chunk_z_max)
-        depth_offset = 1;
+    auto offset = _camera + tile_shader::project(Vector3d(c_.x, c_.y, 0) * chunk_size);
+    auto pos  = Vector2d(chunk_coords(c_) - first_);
+    auto len = Vector2d(last_ - first_) + Vector2d(1, 1);
+    auto pos1 = pos.y() * len.x() + pos.x();
+    auto z = c_.z - chunk_z_min;
+    constexpr auto depth_start = -1 + 1.111e-16;
+
+    double chunk_offset, tile_offset;
+
+    if (c_.z < chunk_z_max)
+    {
+        chunk_offset = depth_start + tile_shader::depth_chunk_size * pos1;
+        tile_offset = (double)tile_shader::depth_value({z, z});
+    }
+    else
+    {
+        chunk_offset = 1;
+        tile_offset = 0;
+    }
+
+    double depth_offset_ = chunk_offset + tile_offset;
+    auto depth_offset = (float)depth_offset_;
 
     _shader.set_camera_offset(offset, depth_offset);
 }
diff --git a/src/chunk-render.cpp b/src/chunk-render.cpp
index 802cb11a..28bdc759 100644
--- a/src/chunk-render.cpp
+++ b/src/chunk-render.cpp
@@ -71,7 +71,7 @@ GL::Mesh chunk::make_wall_mesh(size_t count)
         const local_coords pos{i / 2u};
         const auto center = Vector3(pos) * TILE_SIZE;
         const auto quad = i & 1 ? atlas->wall_quad_W(center, TILE_SIZE) : atlas->wall_quad_N(center, TILE_SIZE);
-        const float depth = tile_shader::depth_value(pos);
+        const float depth = tile_shader::depth_value(pos, tile_shader::wall_depth_offset);
         const auto texcoords = atlas->texcoords_for_id(variant);
         auto& v = vertexes[k];
         for (auto j = 0uz; j < 4; j++)
diff --git a/src/global-coords.hpp b/src/global-coords.hpp
index a5f9dff0..737fc21b 100644
--- a/src/global-coords.hpp
+++ b/src/global-coords.hpp
@@ -20,6 +20,8 @@ struct chunk_coords final {
     template<typename T>
     requires (std::is_floating_point_v<T> || std::is_integral_v<T> && (sizeof(T) > sizeof(x) || std::is_same_v<T, std::decay_t<decltype(x)>>))
     explicit constexpr operator Math::Vector3<T>() const noexcept { return Math::Vector3<T>(T(x), T(y), T(0)); }
+
+    constexpr Vector2i operator-(chunk_coords other) const noexcept { return Vector2i{x - other.x, y - other.y }; }
 };
 
 struct chunk_coords_ final {
@@ -55,7 +57,9 @@ struct chunk_coords_ final {
         x = int16_t(x - int{off.x()}); y = int16_t(y - int{off.y()}); z = int8_t(z - off.z()); return *this;
     }
 
-    Vector3i operator-(chunk_coords_ other) const noexcept { return Vector3i{x - other.x, y - other.y, z - other.z}; }
+    constexpr Vector3i operator-(chunk_coords_ other) const noexcept { return Vector3i{x - other.x, y - other.y, z - other.z}; }
+
+    explicit operator chunk_coords() const noexcept { return chunk_coords{x, y}; }
 };
 
 constexpr inline int8_t chunk_z_min = -1, chunk_z_max = 14;