public static BMPImage ConvertDDSToBMP(DDSImage dds)
{
//Creates new empty BMP file
BMPImage bmp = new BMPImage((UInt32)dds.Width, (UInt32)dds.Height);
//container for colors
RGBColor[] colors = new RGBColor[4];
int texelsX = (int)dds.Width / 4;
int x, y = 0;
//iterates through all data in DDS file
for (int i = 0; i < dds.ImageDataLength; i++)
{
DDSImage.TexelBlock t = dds.GetImageData(i);
colors = ReadMainColors(t);
RGBColor color = new RGBColor(0, 0, 0);
byte[] texelCol = new byte[4];
for (int k = 0; k < t.blocks.Length; k++)
{
texelCol[0] = (byte)(t.blocks[k] & 0x3);
texelCol[1] = (byte)((t.blocks[k] & 0xC) >> 2);
texelCol[2] = (byte)((t.blocks[k] & 0x30) >> 4);
texelCol[3] = (byte)((t.blocks[k] & 0xC0) >> 6);
for (int j = 0; j < 4; j++)
{
color = colors[texelCol[j]];
x = (i % texelsX) * 4 + j;
y = ((int)dds.Height - 1) - ((i / texelsX) * 4) - k;
bmp.AddImageData(x, y, color);
}
}
}
bmp.Save(dds.FileName);
return(bmp);
}
private static RGBColor[] ReadMainColors(DDSImage.TexelBlock texel)
{
RGBColor[] colors = new RGBColor[4];
RGBColor rgbColor0 = ImageUtils.ConvertRGB565ToRGB888(texel.color0);
RGBColor rgbColor1 = ImageUtils.ConvertRGB565ToRGB888(texel.color1);
RGBColor rgbColor2 = new RGBColor(
(int)((2.0f / 3.0f) * rgbColor0.R + (1.0f / 3.0f) * rgbColor1.R),
(int)((2.0f / 3.0f) * rgbColor0.G + (1.0f / 3.0f) * rgbColor1.G),
(int)((2.0f / 3.0f) * rgbColor0.B + (1.0f / 3.0f) * rgbColor1.B));
RGBColor rgbColor3 = new RGBColor(
(int)((1.0f / 3.0f) * rgbColor0.R + (2.0f / 3.0f) * rgbColor1.R),
(int)((1.0f / 3.0f) * rgbColor0.G + (2.0f / 3.0f) * rgbColor1.G),
(int)((1.0f / 3.0f) * rgbColor0.B + (2.0f / 3.0f) * rgbColor1.B));
colors[0] = rgbColor0;
colors[1] = rgbColor1;
colors[2] = rgbColor2;
colors[3] = rgbColor3;
return(colors);
}
private static DDSImage.TexelBlock CompressDataBlock(RGBColor[] block)
{
//Finds max and min color
RGBColor maxColor = new RGBColor(0, 0, 0);
RGBColor minColor = new RGBColor(255, 255, 255);
float max = 0;
float min = 255f;
for (int i = 0; i < block.Length; i++)
{
//Note: Testing Luminance to determine max and min color, but having some artifacts on pic
/*
if(max<Math.Max(max, ImageUtils.ColorBrightness(block[i])))
{
max = Math.Max(max, ImageUtils.ColorBrightness(block[i]));
maxColor = block[i];
}
if (min > Math.Min(min, ImageUtils.ColorBrightness(block[i])))
{
min = Math.Min(min, ImageUtils.ColorBrightness(block[i]));
minColor = block[i];
}*/
maxColor = ImageUtils.Max(maxColor, block[i]);
minColor = ImageUtils.Min(minColor, block[i]);
}
DDSImage.TexelBlock tb = new DDSImage.TexelBlock();
tb.blocks = new byte[4];
UInt16 color2 = 0;
UInt16 color3 = 0;
tb.color0 = ImageUtils.ConvertRGB888ToRGB565(maxColor);
tb.color1 = ImageUtils.ConvertRGB888ToRGB565(minColor);
//Interpolate color2 and color3
int B = (int)(((2.0f / 3.0f) * maxColor.B) + ((1.0f / 3.0f) * minColor.B));
int G = (int)(((2.0f / 3.0f) * maxColor.G) + ((1.0f / 3.0f) * minColor.G));
int R = (int)(((2.0f / 3.0f) * maxColor.R) + ((1.0f / 3.0f) * minColor.R));
color2 = ImageUtils.ConvertRGB888ToRGB565(new RGBColor(R, G, B));
B = (int)(((1.0f / 3.0f) * maxColor.B) + ((2.0f / 3.0f) * minColor.B));
G = (int)(((1.0f / 3.0f) * maxColor.G) + ((2.0f / 3.0f) * minColor.G));
R = (int)(((1.0f / 3.0f) * maxColor.R) + ((2.0f / 3.0f) * minColor.R));
color3 = ImageUtils.ConvertRGB888ToRGB565(new RGBColor(R, G, B));
float[] distances = new float[4];
int colorTableColIndex = 0;
int colorTableRowIndex = 0;
int colorTableRow = 0;
//iterates through 16 block of colors
for (int x = 0; x < block.Length; x++)
{
UInt16 rgb565 = ImageUtils.ConvertRGB888ToRGB565(block[x]);
//Euclidean distance between the two colors, no need to sqrt for comparison
distances[0] = (float)Math.Pow(tb.color0 - rgb565, 2f);
distances[1] = (float)Math.Pow(tb.color1 - rgb565, 2f);
distances[2] = (float)Math.Pow(color2 - rgb565, 2f);
distances[3] = (float)Math.Pow(color3 - rgb565, 2f);
//Find minimum distance from calculated values
float minDistance = distances[0];
int indexBlock = 0;
for (int i = 1; i < 4; i++)
{
if (distances[i] < minDistance)
{
minDistance = distances[i];
indexBlock = i;
}
}
//Write the index value to correct position in this color table row
switch (colorTableColIndex)
{
case 0:
colorTableRow = indexBlock;
break;
case 1:
colorTableRow |= (indexBlock << 2);
break;
case 2:
colorTableRow |= (indexBlock << 4);
break;
case 3:
colorTableRow |= (indexBlock << 6);
break;
}
colorTableColIndex++;
//If all four values have been written to this color table row,
//Save it to texel block structure and start getting data from next row
if (colorTableColIndex == 4)
{
tb.blocks[colorTableRowIndex] = (byte)colorTableRow;
colorTableRowIndex++;
colorTableColIndex = 0;
}
}
return tb;
}
private static DDSImage.TexelBlock CompressDataBlock(RGBColor[] block)
{
//Finds max and min color
RGBColor maxColor = new RGBColor(0, 0, 0);
RGBColor minColor = new RGBColor(255, 255, 255);
float max = 0;
float min = 255f;
for (int i = 0; i < block.Length; i++)
{
//Note: Testing Luminance to determine max and min color, but having some artifacts on pic
/*
* if(max<Math.Max(max, ImageUtils.ColorBrightness(block[i])))
* {
* max = Math.Max(max, ImageUtils.ColorBrightness(block[i]));
* maxColor = block[i];
* }
* if (min > Math.Min(min, ImageUtils.ColorBrightness(block[i])))
* {
* min = Math.Min(min, ImageUtils.ColorBrightness(block[i]));
* minColor = block[i];
* }*/
maxColor = ImageUtils.Max(maxColor, block[i]);
minColor = ImageUtils.Min(minColor, block[i]);
}
DDSImage.TexelBlock tb = new DDSImage.TexelBlock();
tb.blocks = new byte[4];
UInt16 color2 = 0;
UInt16 color3 = 0;
tb.color0 = ImageUtils.ConvertRGB888ToRGB565(maxColor);
tb.color1 = ImageUtils.ConvertRGB888ToRGB565(minColor);
//Interpolate color2 and color3
int B = (int)(((2.0f / 3.0f) * maxColor.B) + ((1.0f / 3.0f) * minColor.B));
int G = (int)(((2.0f / 3.0f) * maxColor.G) + ((1.0f / 3.0f) * minColor.G));
int R = (int)(((2.0f / 3.0f) * maxColor.R) + ((1.0f / 3.0f) * minColor.R));
color2 = ImageUtils.ConvertRGB888ToRGB565(new RGBColor(R, G, B));
B = (int)(((1.0f / 3.0f) * maxColor.B) + ((2.0f / 3.0f) * minColor.B));
G = (int)(((1.0f / 3.0f) * maxColor.G) + ((2.0f / 3.0f) * minColor.G));
R = (int)(((1.0f / 3.0f) * maxColor.R) + ((2.0f / 3.0f) * minColor.R));
color3 = ImageUtils.ConvertRGB888ToRGB565(new RGBColor(R, G, B));
float[] distances = new float[4];
int colorTableColIndex = 0;
int colorTableRowIndex = 0;
int colorTableRow = 0;
//iterates through 16 block of colors
for (int x = 0; x < block.Length; x++)
{
UInt16 rgb565 = ImageUtils.ConvertRGB888ToRGB565(block[x]);
//Euclidean distance between the two colors, no need to sqrt for comparison
distances[0] = (float)Math.Pow(tb.color0 - rgb565, 2f);
distances[1] = (float)Math.Pow(tb.color1 - rgb565, 2f);
distances[2] = (float)Math.Pow(color2 - rgb565, 2f);
distances[3] = (float)Math.Pow(color3 - rgb565, 2f);
//Find minimum distance from calculated values
float minDistance = distances[0];
int indexBlock = 0;
for (int i = 1; i < 4; i++)
{
if (distances[i] < minDistance)
{
minDistance = distances[i];
indexBlock = i;
}
}
//Write the index value to correct position in this color table row
switch (colorTableColIndex)
{
case 0:
colorTableRow = indexBlock;
break;
case 1:
colorTableRow |= (indexBlock << 2);
break;
case 2:
colorTableRow |= (indexBlock << 4);
break;
case 3:
colorTableRow |= (indexBlock << 6);
break;
}
colorTableColIndex++;
//If all four values have been written to this color table row,
//Save it to texel block structure and start getting data from next row
if (colorTableColIndex == 4)
{
tb.blocks[colorTableRowIndex] = (byte)colorTableRow;
colorTableRowIndex++;
colorTableColIndex = 0;
}
}
return(tb);
}
