ByteArray - getPixels() & setPixels()
From Director Online Wiki
Description
getPixels(imageFormat) setPixels(bytearray {, imageFormat} )
imageFormat can be one of these values:
#RGBA8888, #ARGB8888, #RGB888, #BGR888
Byte array method; creates (or reads from) a byte array that is initialized with 24bit or 32bit image data.
Example
bArray = image.getPixels(#RGBA8888) image.setPixels(bArray,#RGBA8888)
More Info
If you want to make your code as speedy as you can then do a test against the image member's .useAlpha() property. If a 32-bit image with an actual alpha channel is imported then the .useAlpha() = 1 = #RGBA8888 = 4 bytes per pixel and if not (ie. it's a 24-bit image, which Director doesn't distinguish with the .depth property) then .useAlpha() = 0 = #RGB888 = 3 bytes per pixel.
Speed Comparison With getPixel()
on multiplyBlendMode (image1, image2) theStart = the milliseconds newWidth = max(image1.width, image2.width) newHeight = max(image1.height, image2.height) newImage = image(newWidth, newHeight, 32) baNew = newImage.getPixels(#RGBA8888) baImg1 = image1.getPixels(#RGBA8888) baImg2 = image2.getPixels(#RGBA8888) len = baNew.length repeat with i = 1 to len baNew[i] = baImg1[i] * baImg2[i] / 255 end repeat newImage.setPixels(baNew, #RGBA8888) put the milliseconds - theStart return newImage end
which is faster than the old getPixel() method:
on multiplyBlendMode (image1, image2) theWidth = image1.width - 1 theHeight = image1.height - 1 theImage = image(theWidth + 1, theHeight + 1, 32) repeat with x = 0 to theWidth repeat with y = 0 to theHeight theColour1 = image1.getPixel(point(x,y)) theColour2 = image2.getPixel(point(x,y)) theRed = theColour1.red * theColour2.red / 255.0 theGreen = theColour1.green * theColour2.green / 255.0 theBlue = theColour1.blue * theColour2.blue / 255.0 theNewColour = color(theRed, theGreen, theBlue) theImage.setPixel(point(x, y), theNewColour) end repeat end repeat return theImage end
.... using two 1024x768 images (no alpha channel) here are the averaged results (of 3 tests each):
- 1768 ms - byteArray getPixels() - 24bit, ~48% faster
- 2351 ms - byteArray getPixels() - 32bit, ~30% faster (without testing for the alpha channel)
- 3378 ms - getPixel()