Move SnesTo8bppSheet to gfx namespace

src/app/gfx/snes_tile.cc

@@ -9,6 +9,53 @@ namespace yaze {
 namespace app {
 namespace gfx {
 
+Bytes SnesTo8bppSheet(Bytes sheet, int bpp) {
+  int xx = 0;  // positions where we are at on the sheet
+  int yy = 0;
+  int pos = 0;
+  int ypos = 0;
+  int num_tiles = 64;
+  int buffer_size = 0x1000;
+  if (bpp == 2) {
+    bpp = 16;
+    num_tiles = 128;
+    buffer_size = 0x2000;
+  } else if (bpp == 3) {
+    bpp = 24;
+  }
+  Bytes sheet_buffer_out(buffer_size);
+
+  for (int i = 0; i < num_tiles; i++) {  // for each tiles, 16 per line
+    for (int y = 0; y < 8; y++) {        // for each line
+      for (int x = 0; x < 8; x++) {      //[0] + [1] + [16]
+        auto b1 = (sheet[(y * 2) + (bpp * pos)] & (kGraphicsBitmap[x]));
+        auto b2 = (sheet[((y * 2) + (bpp * pos)) + 1] & (kGraphicsBitmap[x]));
+        auto b3 = (sheet[(16 + y) + (bpp * pos)] & (kGraphicsBitmap[x]));
+        unsigned char b = 0;
+        if (b1 != 0) {
+          b |= 1;
+        }
+        if (b2 != 0) {
+          b |= 2;
+        }
+        if (b3 != 0 && bpp != 16) {
+          b |= 4;
+        }
+        sheet_buffer_out[x + xx + (y * 128) + (yy * 1024)] = b;
+      }
+    }
+    pos++;
+    ypos++;
+    xx += 8;
+    if (ypos >= 16) {
+      yy++;
+      xx = 0;
+      ypos = 0;
+    }
+  }
+  return sheet_buffer_out;
+}
+
 TileInfo GetTilesInfo(ushort tile) {
   // vhopppcc cccccccc
   bool o = false;

src/app/gfx/snes_tile.h

@@ -10,6 +10,11 @@ namespace yaze {
 namespace app {
 namespace gfx {
 
+constexpr uchar kGraphicsBitmap[8] = {0x80, 0x40, 0x20, 0x10,
+                                      0x08, 0x04, 0x02, 0x01};
+
+Bytes SnesTo8bppSheet(Bytes sheet, int bpp);
+
 struct tile8 {
   unsigned int id;
   char data[64];