/// <summary>
/// Calculates the margins of a sprite, essentially trimming away empty space (alpha = 0)
/// </summary>
/// <param name="sprite">Sprite to calculate margins for</param>
private static void CalculateSpriteMargins(UnpackedSprite sprite)
{
var pixels = sprite.pixels;
int left = sprite.width;
int top = sprite.height;
int right = 0;
int bottom = 0;
int i = 0;
for (int y = 0; y < sprite.height; y++)
{
bool pixelPresent = false;
for (int x = 0; x < sprite.width; x++)
{
if (pixels[i].a != 0)
{
if (x < left)
{
left = x;
}
if (x > right)
{
right = x;
}
pixelPresent = true;
}
i++;
}
if (pixelPresent)
{
if (y < top)
{
top = y;
}
if (y > bottom)
{
bottom = y;
}
}
}
// If we didn't find any pixels then flag the sprite as empty
if (left == sprite.width)
{
sprite.isEmpty = true;
sprite.size = 0;
}
else
{
sprite.pixelRect = new Rect2i(left, top, right - left + 1, bottom - top + 1);
sprite.size = sprite.pixelRect.width * sprite.pixelRect.height;
}
}
private static int CompareSpriteSizeBiggestFirst(UnpackedSprite sprite1, UnpackedSprite sprite2)
{
int diff = sprite2.size - sprite1.size;
// Break ties by sequence number. This helps ensures the same sort order on all platforms
if (diff == 0)
{
return(sprite1.seq - sprite2.seq);
}
return(diff);
}
/// <summary>
/// Get pixels from an encoded image buffer. This uses Unity APIs and must be ran on main thread
/// </summary>
/// <param name="sprite">Sprite to decode</param>
/// <param name="workingTexture">Temporary working texture to use</param>
/// <returns>True if successful</returns>
private static bool GetPixelsFromImageBuffer(UnpackedSprite sprite, Texture2D workingTexture)
{
#if !RETROBLIT_STANDALONE
if (sprite.imageBytes == null)
{
return(false);
}
workingTexture.LoadImage(sprite.imageBytes, false);
sprite.pixels = workingTexture.GetPixels32();
sprite.width = workingTexture.width;
sprite.height = workingTexture.height;
sprite.size = sprite.width * sprite.height;
sprite.pixelRect = new Rect2i(0, 0, sprite.width, sprite.height);
#endif
return(true);
}
