From d51bb7b3d0a55d5e297c588b2a1136417d895fc0 Mon Sep 17 00:00:00 2001
From: scawful <justin.scofield@outlook.com>
Date: Wed, 2 Aug 2023 07:15:55 -0400
Subject: [PATCH] Add BPP8SNESToIndexed to snes_tile for cgx

---
 src/app/gfx/snes_tile.cc     | 97 ++++++++++++++++++++++++++++++++++++
 src/app/gfx/snes_tile.h      |  1 +
 src/app/viewer/cgx_viewer.cc |  2 +-
 3 files changed, 99 insertions(+), 1 deletion(-)

diff --git a/src/app/gfx/snes_tile.cc b/src/app/gfx/snes_tile.cc
index 78d43240..861b48f7 100644
--- a/src/app/gfx/snes_tile.cc
+++ b/src/app/gfx/snes_tile.cc
@@ -56,6 +56,103 @@ Bytes SnesTo8bppSheet(Bytes sheet, int bpp) {
   return sheet_buffer_out;
 }
 
+Bytes BPP8SNESToIndexed(Bytes data, uint64_t bpp) {
+  // 3BPP
+  //[r0, bp1], [r0, bp2], [r1, bp1], [r1, bp2], [r2, bp1], [r2, bp2], [r3, bp1],
+  //[r3, bp2] [r4, bp1], [r4, bp2], [r5, bp1], [r5, bp2], [r6, bp1], [r6, bp2],
+  //[r7, bp1], [r7, bp2] [r0, bp3], [r0, bp4], [r1, bp3], [r1, bp4], [r2, bp3],
+  //[r2, bp4], [r3, bp3], [r3, bp4] [r4, bp3], [r4, bp4], [r5, bp3], [r5, bp4],
+  //[r6, bp3], [r6, bp4], [r7, bp3], [r7, bp4] [r0, bp5], [r0, bp6], [r1, bp5],
+  //[r1, bp6], [r2, bp5], [r2, bp6], [r3, bp5], [r3, bp6] [r4, bp5], [r4, bp6],
+  //[r5, bp5], [r5, bp6], [r6, bp5], [r6, bp6], [r7, bp5], [r7, bp6] [r0, bp7],
+  //[r0, bp8], [r1, bp7], [r1, bp8], [r2, bp7], [r2, bp8], [r3, bp7], [r3, bp8]
+  //[r4, bp7], [r4, bp8], [r5, bp7], [r5, bp8], [r6, bp7], [r6, bp8], [r7, bp7],
+  //[r7, bp8]
+
+  // 16 tiles = 1024 bytes
+  auto buffer = Bytes(data.size());
+  auto bitmap_data = Bytes(128 * 128 + 2048);
+  int yy = 0;
+  int xx = 0;
+  int pos = 0;
+
+  const uint16_t sheet_width = 128;
+
+  // 64 = 4096 bytes
+  // 16 = 1024?
+  int ypos = 0;
+  // for each tiles //16 per lines
+  for (int i = 0; i < 4096; i++) {
+    // for each lines
+    for (int y = 0; y < 8; y++) {
+      //[0] + [1] + [16]
+      for (int x = 0; x < 8; x++) {
+        const uint16_t bitmask[] = {0x80, 0x40, 0x20, 0x10,
+                                    0x08, 0x04, 0x02, 0x01};
+        auto b1 = ((data[(y * 2) + ((bpp * 8) * pos)] & (bitmask[x])));
+        auto b2 = (data[((y * 2) + ((bpp * 8) * pos)) + 1] & (bitmask[x]));
+        auto b3 = (data[(y * 2) + ((bpp * 8) * pos) + 16] & (bitmask[x]));
+        auto b4 = (data[(y * 2) + ((bpp * 8) * pos) + 17] & (bitmask[x]));
+        auto b5 = (data[(y * 2) + ((bpp * 8) * pos) + 32] & (bitmask[x]));
+        auto b6 = (data[(y * 2) + ((bpp * 8) * pos) + 33] & (bitmask[x]));
+        auto b7 = (data[(y * 2) + ((bpp * 8) * pos) + 48] & (bitmask[x]));
+        auto b8 = (data[(y * 2) + ((bpp * 8) * pos) + 49] & (bitmask[x]));
+
+        auto b = 0;
+        if (b1 != 0) {
+          b |= 1;
+        };
+        if (b2 != 0) {
+          b |= 2;
+        };
+        if (bpp >= 4) {
+          if (b3 != 0) {
+            b |= 4;
+          };
+          if (b4 != 0) {
+            b |= 8;
+          };
+        }
+        if (bpp >= 8) {
+          if (b5 != 0) {
+            b |= 0x10;
+          };
+          if (b6 != 0) {
+            b |= 0x20;
+          };
+          if (b7 != 0) {
+            b |= 0x40;
+          };
+          if (b8 != 0) {
+            b |= 0x80;
+          };
+        }
+        bitmap_data[((x + xx) * sheet_width) + y + (yy * 8)] = b;
+      }
+    }
+    pos++;
+    ypos++;
+    xx += 8;
+    if (ypos >= 16) {
+      yy++;
+      xx = 0;
+      ypos = 0;
+    }
+  }
+
+  int n = 0;
+
+  for (int y = 0; y < (data.size() / 64); y++) {
+    for (int x = 0; x < sheet_width; x++) {  // 128 assumption
+      if (n < data.size()) {
+        buffer[n] = bitmap_data[(x * sheet_width) + y];
+        n++;
+      }
+    }
+  }
+  return buffer;
+}
+
 TileInfo GetTilesInfo(ushort tile) {
   // vhopppcc cccccccc
   bool o = false;
diff --git a/src/app/gfx/snes_tile.h b/src/app/gfx/snes_tile.h
index 901562f8..0d18acaf 100644
--- a/src/app/gfx/snes_tile.h
+++ b/src/app/gfx/snes_tile.h
@@ -14,6 +14,7 @@ constexpr uchar kGraphicsBitmap[8] = {0x80, 0x40, 0x20, 0x10,
                                       0x08, 0x04, 0x02, 0x01};
 
 Bytes SnesTo8bppSheet(Bytes sheet, int bpp);
+Bytes BPP8SNESToIndexed(Bytes data, uint64_t bpp = 0);
 
 struct tile8 {
   unsigned int id;
diff --git a/src/app/viewer/cgx_viewer.cc b/src/app/viewer/cgx_viewer.cc
index 506ba856..8352b414 100644
--- a/src/app/viewer/cgx_viewer.cc
+++ b/src/app/viewer/cgx_viewer.cc
@@ -67,7 +67,7 @@ void CgxViewer::LoadGfx(int combo_bpp) {
     return;
   }
 
-  Bytes decomp_sheet = gfx::SnesTo8bppSheet(raw_data_.vector(), bpp_);
+  Bytes decomp_sheet = gfx::BPP8SNESToIndexed(raw_data_.vector(), bpp_);
   for (int i = 0; i < decomp_sheet.size(); i++) {
     all_tiles_data_[i] = decomp_sheet[i];
   }