1 files changed, 42 insertions, 0 deletions
diff --git a/src/mbgl/geometry/debug_font_buffer.cpp b/src/mbgl/geometry/debug_font_buffer.cpp
new file mode 100644
index 0000000000..1ec71463e5
--- /dev/null
+++ b/src/mbgl/geometry/debug_font_buffer.cpp
@@ -0,0 +1,42 @@
+#include <mbgl/geometry/debug_font_buffer.hpp>
+#include <mbgl/geometry/debug_font_data.hpp>
+
+#include <mbgl/platform/gl.hpp>
+#include <cmath>
+#include <cstring>
+
+using namespace mbgl;
+
+void DebugFontBuffer::addText(const char *text, double left, double baseline, double scale) {
+    uint16_t *coords = nullptr;
+
+    const size_t len = strlen(text);
+    for (size_t i = 0; i < len; ++i) {
+        if (text[i] < 32 || (unsigned char)(text[i]) >= 127) {
+            continue;
+        }
+
+        const glyph& glyph = simplex[text[i] - 32];
+
+        int16_t prev_x = -1, prev_y = -1, prev = false;
+        for (int32_t j = 0; j < glyph.length; j += 2) {
+            if (glyph.data[j] == -1 && glyph.data[j + 1] == -1) {
+                prev = false;
+            } else {
+                int16_t x = std::round(left + glyph.data[j] * scale);
+                int16_t y = std::round(baseline - glyph.data[j + 1] * scale);
+                if (prev) {
+                    coords = static_cast<uint16_t *>(addElement());
+                    coords[0] = prev_x;
+                    coords[1] = prev_y;
+
+                    coords = static_cast<uint16_t *>(addElement());
+                    coords[0] = x;
+                    coords[1] = y;
+                }
+                prev_x = x; prev_y = y; prev = true;
+            }
+        }
+        left += glyph.width * scale;
+    }
+}