Add screen(), memory mapped frame buffer
diff --git a/screen.c b/screen.c
new file mode 100644
index 0000000..2eb17a2
--- /dev/null
+++ b/screen.c
@@ -0,0 +1,38 @@
+#include "screen.h"
+#include "cpu.h"
+
+struct nk_color byte_to_color(uint8_t b)
+{
+ struct nk_color c;
+ c.r = (b >> 6) * (255 / 0b11);
+ c.g = ((b >> 2) & 0b111) * (255 / 0b111);
+ c.b = (b & 0b11) * (255 / 0b11);
+ c.a = 255;
+ return c;
+}
+
+void screen(struct nk_context *ctx, uint8_t *mem, uint8_t size)
+{
+ struct nk_command_buffer *out = nk_window_get_canvas(ctx);
+
+ struct nk_rect bounds;
+ enum nk_widget_layout_states state = nk_widget(&bounds, ctx);
+
+ if (!state)
+ return;
+
+ //nk_fill_rect(out, bounds, 0, nk_rgb(255, 0, 0));
+
+ //return;
+
+ for (int i = 0; i < CPU_FB_H; i++)
+ {
+ for (int j = 0; j < CPU_FB_W; j++)
+ {
+ nk_fill_rect(out,
+ nk_rect(bounds.x + i * size, bounds.y + j * size,
+ size, size), 0.0f,
+ byte_to_color(mem[i * CPU_FB_H + j]));
+ }
+ }
+}