GBA raw graphics function

[Madsiur]

I've been working on a graphic editor for FF6A for some times now. The graphics are appearing fine in the editor with the correct palettes and colors but when I save them they appears as this in the game:



This happens even when I make no changes to the portraits. I figured it had something to do with the function that change the WriteableBitmap in a byte array. I took the function from an open source GBA graphic editor that already exists and modified it a bit. Here's the function:

Code Select Expand


        static public byte[] toGbaRaw(WriteableBitmap wBmp, int emptyGraphBlocks, List<Color> pal)
        {
            byte[] result = new byte[wBmp.PixelWidth * wBmp.PixelHeight * (int)bpp / 8 - emptyGraphBlocks * 8 * (int)bpp];

            for (int i = 0; i < result.Length; i++)
            {
                // bpp value is 4
                Point coord = tiledCoord(i * 8 / (int)bpp, wBmp.PixelWidth, 8);
                Color color1 = wBmp.GetPixel((int)coord.X, (int)coord.Y);
                Color color2 = wBmp.GetPixel((int)coord.X + 1, (int)coord.Y);

                byte value = 0x00;

                // if not transparency
                if(!color1.Equals(Color.FromArgb(0x00, 0x00, 0x00, 0x00)))
                {
                    value = (byte)(pal.IndexOf(color1) & 0xF);
                }

                // if not transparency
                if (!color2.Equals(Color.FromArgb(0x00, 0x00, 0x00, 0x00)))
                {
                    value += (byte)(pal.IndexOf(color2) & 0xF);
                }

                result[i] = value;
            }

            return result;
        }


I've been trying different things to solve this problem in the last few day but nothing seems to work. Does anyone has an idea what would be wrong? Thanks in advance

For the record here's the function that takes a byte array and transform it into a bitmap. This one works correctly:

Code Select Expand


        static public unsafe WriteableBitmap toBmp(byte* graph, int length, int width, Color[] pal, out int emptyGraphPlocks)
        {
            int height, add;
            add = 0;

            if (length % (32 * width) != 0)
                add = 1;

            height = (((length / 32) - (length / 32) % width) / width + add);
            emptyGraphPlocks = (width * height) - (length / 32);

            BitmapPalette bPal = new BitmapPalette(pal);
            WriteableBitmap wBmp = new WriteableBitmap(width * 8, height * 8, 96, 96, PixelFormats.Pbgra32, null);

            for (int i = 0; i < length; i++)
            {
                Point pt = tiledCoord(i * 2, width * 8, 8);
                wBmp.SetPixel((int)pt.X, (int)pt.Y, bPal.Colors[*(graph + i) & 0xF]);
                wBmp.SetPixel((int)(pt.X + 1), (int)pt.Y, bPal.Colors[(*(graph + i) >> 4) & 0xF]);
            }

            return wBmp;
        }


[KC]

You need to shift the second index left by four bits.

Code Select Expand

value |= (byte)((pal.IndexOf(color2) & 0xF) << 4);

[Madsiur]

Yes! That did it! Thanks a lot KC!