rename floor -> ground

1 files changed, 49 insertions, 0 deletions

diff --git a/draw/ground.cpp b/draw/ground.cpp
new file mode 100644
index 00000000..515729b1
--- /dev/null
+++ b/draw/ground.cpp
@@ -0,0 +1,49 @@
+#include "ground.hpp"
+#include "shaders/shader.hpp"
+#include "src/chunk.hpp"
+#include "src/ground-atlas.hpp"
+#include "compat/assert.hpp"
+#include <Magnum/GL/MeshView.h>
+
+namespace floormat {
+
+ground_mesh::ground_mesh() = default;
+
+void ground_mesh::draw(tile_shader& shader, chunk& c)
+{
+    constexpr int quad_index_count = 6;
+    const auto [mesh_, ids, size] = c.ensure_ground_mesh();
+    struct {
+        ground_atlas* atlas = nullptr; size_t pos = 0; } last;
+    GL::MeshView mesh{mesh_};
+
+    [[maybe_unused]] size_t draw_count = 0;
+    fm_debug_assert(size_t(mesh_.count()) == size*quad_index_count);
+
+    const auto do_draw = [&](size_t i, ground_atlas* atlas, uint32_t max_index) {
+        if (atlas == last.atlas)
+            return;
+        if (auto len = i - last.pos; last.atlas && len > 0)
+        {
+            mesh.setCount((int)(quad_index_count * len));
+            mesh.setIndexOffset((int)(last.pos*quad_index_count), 0, max_index);
+            shader.draw(last.atlas->texture(), mesh);
+            draw_count++;
+        }
+        last = { atlas, i };
+    };
+
+    const auto max_index = uint32_t(size*quad_index_count - 1);
+    size_t k;
+    for (k = 0; k < size; k++)
+        do_draw(k, c.ground_atlas_at(ids[k]), max_index);
+    do_draw(size, nullptr, max_index);
+
+//#define FM_DEBUG_DRAW_COUNT
+#ifdef FM_DEBUG_DRAW_COUNT
+    if (draw_count)
+        fm_debug("ground draws: %zu", draw_count);
+#endif
+}
+
+} // namespace floormat