Implement split-screen footer

testbed.c

@@ -33,9 +33,18 @@ typedef struct {
   unsigned int i[16];
 } Tile_t;
 
-unsigned int PAGE[] = { 0x00, 0x20, 0x40, 0x60 };
-// todo: HIGH BITS??
+unsigned int PAGE[] = { 0x04, 0x24 };
+
 #define setWriteMode(m) outport(REG_GDC, 0x05 | m << 8)
+void setSplitScreen(unsigned int y) {
+// TODO: VGA registers??
+  outport(REG_CRTC, 0x1018);// | y << 8);
+  outport(REG_CRTC, 0x0107);
+}
+void unsetSplitScreen() {
+  outport(REG_CRTC, 0xff18);
+  outport(REG_CRTC, 0x1107);
+}
 
 void prepareEgaMemCopy() {
   setAllPlanes();
@@ -51,20 +60,6 @@ void blitTile(unsigned int offsetFrom, unsigned int offsetTo) {
   }
 }
 
-#if 0
-void blitTile(Tile_t *tile, int plane, unsigned int page, unsigned int x, unsigned int y) {
-  unsigned int *data = tile->b + (plane << 4);
-  volatile unsigned int far *out = (volatile unsigned int far *)
-    &VID[(y * 640) + (x << 1) + (page << 8)];
-  int i;
-
-  for (i = 0; i < 320; i += 20) {
-    out[i] = *(data++);
-  }
-}
-
-#endif
-
 #define flipPage(p) outport(REG_CRTC, 0x0c | (p << 8))
 
 /*** K E Y B O A R D ***/
@@ -360,14 +355,14 @@ int tifLoadEGA(FILE *f, TifImageMeta_t meta, unsigned int vidOffset, int maxY) {
 	int gpair = (pixelpair & 0x02) >> 1 | (pixelpair & 0x20) >> 4;
 	int rpair = (pixelpair & 0x04) >> 2 | (pixelpair & 0x40) >> 5;
 	int ipair = (pixelpair & 0x08) >> 3 | (pixelpair & 0x80) >> 6;
-	int shift = (ipixelpair % 4) << 1;
+	int shift = (3 - (ipixelpair % 4)) << 1;
 
 	b |= bpair << shift;
 	g |= gpair << shift;
 	r |= rpair << shift;
 	i |= ipair << shift;
 
-	if (shift == 6 || ipixelpair == ipixelpairLim - 1) {
+	if (shift == 0 || ipixelpair == ipixelpairLim - 1) {
 	  // todo: use write mode 2, this is slooww
 	  setPlane(PLANE_B); *out = b;
 	  setPlane(PLANE_R); *out = r;
@@ -478,7 +473,14 @@ int main() {
   unsigned int page = 0;
 
   #define OFF_TILES 0x4200
+
   setEGAMode();
+  atexit(vid_cleanup);
+
+  f = fopen("FOOTER.TIF", "rb");
+  meta = tifLoadMeta(f);
+  tifLoadEGA(f, meta, 0, 24);
+  fclose(f);
 
   f = fopen("TILES.TIF", "rb");
   meta = tifLoadMeta(f);
@@ -487,21 +489,22 @@ int main() {
 
   mouse_init();
   kbd_init();
-  atexit(vid_cleanup);
 
   while (!keyPressed(K_ESC)) {
-    page ^= 0x20;
+    page ^= 1;
 
     prepareEgaMemCopy();
-    drawOffset = page << 8;
-    for (y = 0; y < 13; y ++) {
+    drawOffset = PAGE[page] << 8;
+    for (y = 0; y < 11; y ++) {
       for (x = 0; x < 20; x ++) {
 	blitTile(OFF_TILES + ((((x + y + z) >> 2) % 3) << 5), drawOffset);
 	drawOffset += 2;
       }
       drawOffset += 600; // 40 bytes per line * 15 more lines
     }
-    flipPage(page);
+
+    flipPage(PAGE[page]);
+    setSplitScreen(16);
 
     kbd_wait();
     z++;