added preprocessor (wip)

1 files changed, 107 insertions, 0 deletions

diff --git a/ROMs/typewriter.c b/ROMs/typewriter.c
new file mode 100644
index 0000000..0886532
--- /dev/null
+++ b/ROMs/typewriter.c
@@ -0,0 +1,107 @@
+#load "font.bin"
+
+int drawChar(int ch, int x, int y, int color)
+{
+    // adjust for jmp instruction
+    char* fontStart = 0x1FFF + 2;
+    int charStart = ch * 8;
+
+    for (int yOff = 0; yOff < 8; yOff++)
+    {
+        int row = fontStart[charStart + yOff];
+
+        for (int xOff = 0; xOff < 8; xOff++)
+        {
+            int bit = (row >> (7 - xOff)) & 1;
+            int pix = bit ? 8 : color;
+            setPixel(x + xOff, y + yOff, pix);
+        }
+    }
+}
+
+int setPixel(int x, int y, int c)
+{
+    char* screenStart = 0x402F;
+    int i = (y * 128) + x;
+    screenStart[i] = c;
+}
+
+int clear(int c)
+{
+    char* screenStart = 0x402F;
+    char screenSize = 64 * 128;
+    for (int i = 0; i < screenSize; i++)
+    {
+        screenStart[i] = c;
+    }
+}
+
+int getKeyState(int scanCode)
+{
+    char* hid = 0x6033;
+    int index = scanCode / 8;
+    int bit   = scanCode % 8;
+
+    int val = hid[index - 1];
+    return (val & (1 << bit)) != 0;
+}
+
+int print(int* text, int len, int x, int y, int color)
+{
+    for (int i = 0; i < len; i++)
+    {
+        int ch = text[i];
+        drawChar(ch, x + (i * 8), y, color);
+    }
+}
+
+int main() 
+{
+    int x = 0;
+    int y = 0;
+    while (1)
+    {
+        for (int sk = 0; sk < 256; sk++)
+        {
+            if (getKeyState(sk))
+            {
+                while (getKeyState(sk)) { }
+                // Newline pressed
+                if (sk == 13)
+                {
+                    y += 8;
+                    x = 0;
+                    continue;
+                }
+                // Backspace pressed
+                if (sk == 8)
+                {
+                    x -= 8;
+                    if (x < 0)
+                        x = 0;
+                    int* text = " ";
+                    print(text, 1, x, y, 1);
+                    continue;
+                }
+                
+                int* text = new int[] { sk };
+                print(text, 1, x, y, 1);
+                x += 8;
+            }
+        }
+
+        if (x >= 128)
+        {
+            x = 0;
+            y += 8;
+        }
+
+        if (y >= 64)
+        {
+            x = 0;
+            y = 0;
+            clear(8);
+        }
+        
+    }
+}
\ No newline at end of file