Buildfix draw_text on non-Windows

ext/native/gfx_es2/draw_text.cpp

@@ -300,7 +300,7 @@ void TextDrawer::DrawString(DrawBuffer &target, const char *str, float x, float
 
 #else
 
-TextDrawer::TextDrawer(DrawContext *thin3d) : thin3d_(thin3d), ctx_(NULL) {
+TextDrawer::TextDrawer(Draw::DrawContext *thin3d) : thin3d_(thin3d), ctx_(NULL) {
 	fontScaleX_ = 1.0f;
 	fontScaleY_ = 1.0f;
 }
@@ -384,6 +384,7 @@ void TextDrawer::MeasureStringRect(const char *str, size_t len, const Bounds &bo
 }
 
 void TextDrawer::DrawString(DrawBuffer &target, const char *str, float x, float y, uint32_t color, int align) {
+	using namespace Draw;
 	if (!strlen(str))
 		return;