Starting on screen impl

libs/core/screen.cpp

@@ -0,0 +1,39 @@
+#include "pxt.h"
+#include "ev3.h"
+
+/**
+* Drawing modes
+*/
+enum class Draw {
+    Normal = DRAW_OPT_NORMAL, // set pixels to black, no fill
+    Clear = DRAW_OPT_CLEAR_PIXELS,
+    Xor = DRAW_OPT_LOGICAL_XOR,
+    Fill = DRAW_OPT_FILL_SHAPE,
+};
+
+#define XX(v) ((uint32_t)(v)&0xffff)
+#define YY(v) ((uint32_t)(v) >> 16)
+
+// We only support up to 4 arguments for C++ functions - need to pack them on the TS side
+namespace screen {
+//%
+void _drawLine(uint32_t p0, uint32_t p1, Draw mode) {
+    LineOutEx(XX(p0), YY(p0), XX(p1), YY(p1), (uint32_t)mode);
+}
+
+//%
+void _drawRect(uint32_t p0, uint32_t p1, Draw mode) {
+    RectOutEx(XX(p0), YY(p0), XX(p1), YY(p1), (uint32_t)mode);
+}
+
+//%
+void _drawEllipse(uint32_t p0, uint32_t p1, Draw mode) {
+    EllipseOutEx(XX(p0), YY(p0), XX(p1), YY(p1), (uint32_t)mode);
+}
+
+/** Draw text. */
+//%
+void drawText(int x, int y, String text, Draw mode) {
+    LcdText((int)mode & (int)Draw::Clear ? 0 : 1, x, y, text->data);
+}
+}