diff --git a/pixie.nimble b/pixie.nimble
index 6ba1661..3604207 100644
--- a/pixie.nimble
+++ b/pixie.nimble
@@ -1,3 +1,4 @@
+packageName = "pixie"
version = "0.0.1"
author = "Andre von Houck and Ryan Oldenburg"
description = "Full-featured 2d graphics library for Nim."
@@ -9,4 +10,4 @@ requires "nim >= 1.2.6"
requires "vmath >= 0.3.2"
requires "chroma >= 0.1.5"
requires "zippy >= 0.3.5"
-requires "flatty >= 0.1.1"
+requires "flatty >= 0.1.2"
diff --git a/src/pixie.nim b/src/pixie.nim
index 7d71504..9cf7e6a 100644
--- a/src/pixie.nim
+++ b/src/pixie.nim
@@ -1,7 +1,7 @@
## Public interface to you library.
-import pixie/images, pixie/masks, pixie/paths
-export images, masks, paths
+import pixie/images, pixie/masks, pixie/paths, pixie/common
+export images, masks, paths, PixieError
proc toMask*(image: Image): Mask =
## Converts an Image to a Mask.
diff --git a/src/pixie/fileformats/png.nim b/src/pixie/fileformats/png.nim
new file mode 100644
index 0000000..3a75136
--- /dev/null
+++ b/src/pixie/fileformats/png.nim
@@ -0,0 +1,443 @@
+import chroma, pixie/images, pixie/common, math, zippy, zippy/crc, flatty/binny
+
+# See http://www.libpng.org/pub/png/spec/1.2/PNG-Contents.html
+
+type
+ ChunkCounts = object
+ PLTE, IDAT: uint8
+
+ PngHeader = object
+ width, height: int
+ bitDepth, colorType, compressionMethod, filterMethod, interlaceMethod: uint8
+
+template failInvalid() =
+ raise newException(PixieError, "Invalid PNG buffer, unable to load")
+
+# template failCRC() =
+# raise newException(PixieError, "CRC check failed")
+
+when defined(release):
+ {.push checks: off.}
+
+proc parseHeader(data: seq[uint8]): PngHeader =
+ result.width = data.readUint32(0).swap().int
+ result.height = data.readUint32(4).swap().int
+ result.bitDepth = data[8]
+ result.colorType = data[9]
+ result.compressionMethod = data[10]
+ result.filterMethod = data[11]
+ result.interlaceMethod = data[12]
+
+ if result.width == 0 or result.width > int32.high.int:
+ raise newException(PixieError, "Invalid PNG width")
+
+ if result.height == 0 or result.height > int32.high.int:
+ raise newException(PixieError, "Invalid PNG height")
+
+ template failInvalidCombo() =
+ raise newException(
+ PixieError, "Invalid PNG color type and bit depth combination"
+ )
+
+ case result.colorType:
+ of 0:
+ if result.bitDepth notin [1.uint8, 2, 4, 8, 16]:
+ failInvalidCombo()
+ of 2:
+ if result.bitDepth notin [8.uint8, 16]:
+ failInvalidCombo()
+ of 3: # PLTE chunk is required, sample depth is always 8 bits
+ if result.bitDepth notin [1.uint8, 2, 4, 8]:
+ failInvalidCombo()
+ of 4:
+ if result.bitDepth notin [8.uint8, 16]:
+ failInvalidCombo()
+ of 6:
+ if result.bitDepth notin [8.uint8, 16]:
+ failInvalidCombo()
+ else:
+ failInvalidCombo()
+
+ if result.compressionMethod != 0:
+ raise newException(PixieError, "Invalid PNG compression method")
+
+ if result.filterMethod != 0:
+ raise newException(PixieError, "Invalid PNG filter method")
+
+ if result.interlaceMethod notin [0.uint8, 1]:
+ raise newException(PixieError, "Invalid PNG interlace method")
+
+ # Not yet supported:
+
+ if result.bitDepth == 16:
+ raise newException(PixieError, "PNG 16 bit depth not yet supported")
+
+ if result.interlaceMethod != 0:
+ raise newException(PixieError, "Interlaced PNG not yet supported")
+
+proc parsePalette(data: seq[uint8]): seq[array[3, uint8]] =
+ if data.len == 0 or data.len mod 3 != 0:
+ failInvalid()
+
+ result.setLen(data.len div 3)
+
+ for i in 0 ..< data.len div 3:
+ result[i] = cast[ptr array[3, uint8]](data[i * 3].unsafeAddr)[]
+
+proc unfilter(
+ uncompressed: seq[uint8], height, rowBytes, bpp: int
+): seq[uint8] =
+ result.setLen(uncompressed.len - height)
+
+ template uncompressedIdx(x, y: int): int =
+ x + y * (rowBytes + 1)
+
+ template unfiteredIdx(x, y: int): int =
+ x + y * rowBytes
+
+ # Unfilter the image data
+ for y in 0 ..< height:
+ let filterType = uncompressed[uncompressedIdx(0, y)]
+ for x in 0 ..< rowBytes:
+ var value = uncompressed[uncompressedIdx(x + 1, y)]
+ case filterType:
+ of 0: # None
+ discard
+ of 1: # Sub
+ if x - bpp >= 0:
+ value += result[unfiteredIdx(x - bpp, y)]
+ of 2: # Up
+ if y - 1 >= 0:
+ value += result[unfiteredIdx(x, y - 1)]
+ of 3: # Average
+ var left, up: int
+ if x - bpp >= 0:
+ left = result[unfiteredIdx(x - bpp, y)].int
+ if y - 1 >= 0:
+ up = result[unfiteredIdx(x, y - 1)].int
+ value += ((left + up) div 2).uint8
+ of 4: # Paeth
+ var left, up, upLeft: int
+ if x - bpp >= 0:
+ left = result[unfiteredIdx(x - bpp, y)].int
+ if y - 1 >= 0:
+ up = result[unfiteredIdx(x, y - 1)].int
+ if x - bpp >= 0 and y - 1 >= 0:
+ upLeft = result[unfiteredIdx(x - bpp, y - 1)].int
+ proc paethPredictor(a, b, c: int): int {.inline.} =
+ let
+ p = a + b - c
+ pa = abs(p - a)
+ pb = abs(p - b)
+ pc = abs(p - c)
+ if pa <= pb and pa <= pc:
+ a
+ elif pb <= pc:
+ b
+ else:
+ c
+ value += paethPredictor(up, left, upLeft).uint8
+ else:
+ discard # Not possible, parseHeader validates
+
+ result[unfiteredIdx(x, y)] = value
+
+proc parseImageData(
+ header: PngHeader, palette: seq[array[3, uint8]], data: seq[uint8]
+): seq[ColorRGBA] =
+ result.setLen(header.width * header.height)
+
+ let
+ uncompressed = try: uncompress(data) except ZippyError: failInvalid()
+ valuesPerPixel =
+ case header.colorType:
+ of 0:
+ 1
+ of 2:
+ 3
+ of 3:
+ 1
+ of 4:
+ 2
+ of 6:
+ 4
+ else:
+ 0 # Not possible, parseHeader validates
+ valuesPerByte = 8 div header.bitDepth.int
+ rowBytes = ceil((header.width.int * valuesPerPixel) / valuesPerByte).int
+ totalBytes = rowBytes * header.height.int
+
+ # Uncompressed image data should be the total bytes of pixel data plus
+ # a filter byte for each row.
+ if uncompressed.len != totalBytes + header.height.int:
+ failInvalid()
+
+ let unfiltered = unfilter(
+ uncompressed,
+ header.height,
+ rowBytes,
+ max(valuesPerPixel div valuesPerByte, 1)
+ )
+
+ var bytePos, bitPos: int
+ for y in 0 ..< header.height:
+ for x in 0 ..< header.width:
+ var rgba: array[4, uint8]
+ case header.colorType:
+ of 0:
+ var value = unfiltered[bytePos]
+ case header.bitDepth:
+ of 1:
+ value = (value shr (7 - bitPos)) and 1
+ value *= 255
+ inc bitPos
+ of 2:
+ value = (value shr (6 - bitPos)) and 3
+ value *= 85
+ inc(bitPos, 2)
+ of 4:
+ value = (value shr (4 - bitPos)) and 15
+ value *= 17
+ inc(bitPos, 4)
+ of 8:
+ inc bytePos
+ else:
+ discard # Not possible, parseHeader validates
+
+ if bitPos == 8:
+ inc bytePos
+ bitPos = 0
+ rgba = [value, value, value, 255]
+ of 2:
+ let rgb = cast[ptr array[3, uint8]](unfiltered[bytePos].unsafeAddr)[]
+ rgba = [rgb[0], rgb[1], rgb[2], 255]
+ inc(bytePos, 3)
+ of 3:
+ var value = unfiltered[bytePos]
+ case header.bitDepth:
+ of 1:
+ value = (value shr (7 - bitPos)) and 1
+ inc bitPos
+ of 2:
+ value = (value shr (6 - bitPos)) and 3
+ inc(bitPos, 2)
+ of 4:
+ value = (value shr (4 - bitPos)) and 15
+ inc(bitPos, 4)
+ of 8:
+ inc bytePos
+ else:
+ discard # Not possible, parseHeader validates
+
+ if bitPos == 8:
+ inc bytePos
+ bitPos = 0
+ if value.int >= palette.len:
+ failInvalid()
+ let rgb = palette[value]
+ rgba = [rgb[0], rgb[1], rgb[2], 255]
+ of 4:
+ rgba = [
+ unfiltered[bytePos],
+ unfiltered[bytePos],
+ unfiltered[bytePos],
+ unfiltered[bytePos + 1]
+ ]
+ inc(bytePos, 2)
+ of 6:
+ rgba = cast[array[4, uint8]](unfiltered.readUint32(bytePos))
+ inc(bytePos, 4)
+ else:
+ discard # Not possible, parseHeader validates
+
+ result[x + y * header.width] = cast[ColorRGBA](rgba)
+
+ # If we move to a new row, skip to the next full byte
+ if bitPos > 0:
+ inc bytePos
+ bitPos = 0
+
+proc decodePng*(data: seq[uint8]): Image =
+ ## Decodes the PNG from the parameter buffer. Check png.channels and
+ ## png.bitDepth to see how the png.data is formatted.
+ ## The returned png.data is currently always RGBA (4 channels)
+ ## with bitDepth of 8.
+
+ if data.len < (8 + (8 + 13 + 4) + 4): # Magic bytes + IHDR + IEND
+ failInvalid()
+
+ # PNG file signature
+ let signature = cast[array[8, uint8]](data.readUint64(0))
+ if signature != [137.uint8, 80, 78, 71, 13, 10, 26, 10]:
+ failInvalid()
+
+ var
+ pos = 8 # After signature
+ counts = ChunkCounts()
+ header: PngHeader
+ palette: seq[array[3, uint8]]
+ imageData: seq[uint8]
+ prevChunkType: string
+
+ # First chunk must be IHDR
+ if data.readUint32(pos).swap() != 13 or
+ data.readStr(pos + 4, 4) != "IHDR":
+ failInvalid()
+ inc(pos, 8)
+ header = parseHeader(data[pos ..< pos + 13])
+ prevChunkType = "IHDR"
+ inc(pos, 13)
+
+ # if crc32(data[pos - 17 ..< pos]) != read32be(data, pos):
+ # failCRC()
+ inc(pos, 4) # CRC
+
+ while true:
+ if pos + 8 > data.len:
+ failInvalid()
+
+ let
+ chunkLen = data.readUint32(pos).swap().int
+ chunkType = data.readStr(pos + 4, 4)
+ inc(pos, 8)
+
+ if chunkLen > high(int32).int:
+ failInvalid()
+
+ if pos + chunkLen + 4 > data.len:
+ failInvalid()
+
+ case chunkType:
+ of "IHDR":
+ failInvalid()
+ of "PLTE":
+ inc counts.PLTE
+ if counts.PLTE > 1 or counts.IDAT > 0:
+ failInvalid()
+ palette = parsePalette(data[pos ..< pos + chunkLen])
+ of "IDAT":
+ inc counts.IDAT
+ if counts.IDAT > 1 and prevChunkType != "IDAT":
+ failInvalid()
+ if header.colorType == 3 and counts.PLTE == 0:
+ failInvalid()
+ let op = imageData.len
+ imageData.setLen(imageData.len + chunkLen)
+ copyMem(imageData[op].addr, data[pos].unsafeAddr, chunkLen)
+ of "IEND":
+ if chunkLen != 0:
+ failInvalid()
+ else:
+ let bytes = cast[seq[uint8]](chunkType)
+ if (bytes[0] and 0b00100000) == 0:
+ raise newException(
+ PixieError, "Unrecognized PNG critical chunk " & chunkType
+ )
+
+ inc(pos, chunkLen)
+
+ # if crc32(data[pos - chunkLen - 4 ..< pos]) != read32be(data, pos):
+ # failCRC()
+ inc(pos, 4) # CRC
+
+ prevChunkType = chunkType
+
+ if pos == data.len:
+ break
+
+ if prevChunkType != "IEND":
+ failInvalid()
+
+ result = Image()
+ result.width = header.width
+ result.height = header.height
+ result.data = parseImageData(header, palette, imageData)
+
+proc encodePng*(
+ width, height, channels: int, data: pointer, len: int
+): seq[uint8] =
+ ## Encodes the image data into the PNG file format.
+
+ if width <= 0 or width > int32.high.int:
+ raise newException(PixieError, "Invalid PNG width")
+
+ if height <= 0 or height > int32.high.int:
+ raise newException(PixieError, "Invalid PNG height")
+
+ if len != width * height * channels:
+ raise newException(PixieError, "Invalid PNG data size")
+
+ let colorType = block:
+ case channels:
+ of 1:
+ 0.uint8
+ of 2:
+ 4
+ of 3:
+ 2
+ of 4:
+ 6
+ else:
+ raise newException(PixieError, "Invalid PNG number of channels")
+
+ # Add the PNG file signature
+ result.add([137.uint8, 80, 78, 71, 13, 10, 26, 10])
+
+ # Add IHDR
+ result.addUint32(13.uint32.swap())
+ result.addStr("IHDR")
+ result.addUint32(width.uint32.swap())
+ result.addUint32(height.uint32.swap())
+ result.add(8.uint8)
+ result.add([colorType, 0, 0, 0])
+ result.addUint32(crc32(result[result.len - 17 ..< result.len]).swap())
+
+ # Add IDAT
+ # Add room for 1 byte before each row for the filter type.
+ var filtered = newSeq[uint8](width * height * channels + height)
+ for y in 0 ..< height:
+ filtered[y * width * channels + y] = 3 # Average
+ for x in 0 ..< width * channels:
+ # Move through the image data byte-by-byte
+ let
+ data = cast[ptr UncheckedArray[uint8]](data)
+ dataPos = y * width * channels + x
+ filteredPos = y * width * channels + y + 1 + x
+ var left, up: int
+ if x - channels >= 0:
+ left = data[dataPos - channels].int
+ if y - 1 >= 0:
+ up = data[(y - 1) * width * channels + x].int
+ let avg = ((left + up) div 2).uint8
+ filtered[filteredPos] = data[dataPos] - avg
+
+ let compressed =
+ try:
+ compress(filtered, DefaultCompression, dfZlib)
+ except ZippyError:
+ raise newException(
+ PixieError, "Unexpected error compressing PNG image data"
+ )
+ if compressed.len > int32.high.int:
+ raise newException(PixieError, "Compressed PNG image data too large")
+
+ result.addUint32(compressed.len.uint32.swap())
+ result.add(cast[seq[uint8]]("IDAT"))
+ result.add(compressed)
+ result.addUint32(
+ crc32(result[result.len - compressed.len - 4 ..< result.len]).swap()
+ )
+
+ # Add IEND
+ result.addUint32(0)
+ result.addStr("IEND")
+ result.addUint32(crc32(result[result.len - 4 ..< result.len]).swap())
+
+proc encodePng*(image: Image): string =
+ ## Encodes the image data into the PNG file format.
+ cast[string](encodePng(
+ image.width, image.height, 4, image.data[0].addr, image.data.len * 4
+ ))
+
+when defined(release):
+ {.pop.}
diff --git a/src/pixie/images.nim b/src/pixie/images.nim
index 91b8629..0adbc21 100644
--- a/src/pixie/images.nim
+++ b/src/pixie/images.nim
@@ -1,4 +1,4 @@
-import strformat, chroma, chroma/blends, vmath
+import chroma, chroma/blends, vmath
type
Image* = ref object
diff --git a/tests/benchmark_png.nim b/tests/benchmark_png.nim
new file mode 100644
index 0000000..1b9c586
--- /dev/null
+++ b/tests/benchmark_png.nim
@@ -0,0 +1,22 @@
+import pixie/fileformats/png, stb_image/read as stbi, fidget/opengl/perf, nimPNG
+
+let data = readFile("tests/data/lenna.png")
+
+timeIt "pixie":
+ for i in 0 ..< 100:
+ discard decodePng(cast[seq[uint8]](data))
+
+timeIt "nimPNG":
+ for i in 0 ..< 100:
+ discard decodePNG32(data)
+
+timeIt "stb_image":
+ for i in 0 ..< 100:
+ var width, height, channels: int
+ discard loadFromMemory(
+ cast[seq[byte]](data),
+ width,
+ height,
+ channels,
+ stbi.RGBA
+ )
diff --git a/tests/data/lenna.png b/tests/data/lenna.png
new file mode 100644
index 0000000..59ef68a
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diff --git a/tests/data/pngsuite/PngSuite.LICENSE b/tests/data/pngsuite/PngSuite.LICENSE
new file mode 100644
index 0000000..8d4d1d0
--- /dev/null
+++ b/tests/data/pngsuite/PngSuite.LICENSE
@@ -0,0 +1,9 @@
+PngSuite
+--------
+
+Permission to use, copy, modify and distribute these images for any
+purpose and without fee is hereby granted.
+
+
+(c) Willem van Schaik, 1996, 2011
+
diff --git a/tests/data/pngsuite/PngSuite.README b/tests/data/pngsuite/PngSuite.README
new file mode 100644
index 0000000..3ef8f24
--- /dev/null
+++ b/tests/data/pngsuite/PngSuite.README
@@ -0,0 +1,25 @@
+ PNGSUITE
+----------------
+
+ testset for PNG-(de)coders
+ created by Willem van Schaik
+------------------------------------
+
+This is a collection of graphics images created to test the png applications
+like viewers, converters and editors. All (as far as that is possible)
+formats supported by the PNG standard are represented.
+
+The suite consists of the following files:
+
+- PngSuite.README - this file
+- PngSuite.LICENSE - the PngSuite is freeware
+- PngSuite.png - image with PngSuite logo
+- PngSuite.tgz - archive of all PNG testfiles
+- PngSuite.zip - same in .zip format for PCs
+
+
+--------
+ (c) Willem van Schaik
+ willem@schaik.com
+ Calgary, April 2011
+
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diff --git a/tests/fuzz_png.nim b/tests/fuzz_png.nim
new file mode 100644
index 0000000..fc15db4
--- /dev/null
+++ b/tests/fuzz_png.nim
@@ -0,0 +1,16 @@
+import random, strformat, pixie/fileformats/png, pixie/common, pngsuite
+
+randomize()
+
+for i in 0 ..< 10_000:
+ let file = pngSuiteFiles[rand(pngSuiteFiles.len - 1)]
+ var data = cast[seq[uint8]](readFile(&"tests/data/pngsuite/{file}.png"))
+ let
+ pos = 29 + rand(data.len - 30)
+ value = rand(255).uint8
+ data[pos] = value
+ echo &"{i} {file} {pos} {value}"
+ try:
+ discard decodePng(data)
+ except PixieError:
+ discard
diff --git a/tests/pngsuite.nim b/tests/pngsuite.nim
new file mode 100644
index 0000000..d843c73
--- /dev/null
+++ b/tests/pngsuite.nim
@@ -0,0 +1,73 @@
+const pngSuiteFiles* = [
+ # Basic
+ "basn0g01", # black & white
+ "basn0g02", # 2 bit (4 level) grayscale
+ "basn0g04", # 4 bit (16 level) grayscale
+ "basn0g08", # 8 bit (256 level) grayscale
+ # "basn0g16", # 16 bit (64k level) grayscale
+ "basn2c08", # 3x8 bits rgb color
+ # "basn2c16", # 3x16 bits rgb color
+ "basn3p01", # 1 bit (2 color) paletted
+ "basn3p02", # 2 bit (4 color) paletted
+ "basn3p04", # 4 bit (16 color) paletted
+ "basn3p08", # 8 bit (256 color) paletted
+ "basn4a08", # 8 bit grayscale + 8 bit alpha-channel
+ # "basn4a16", # 16 bit grayscale + 16 bit alpha-channel
+ "basn6a08", # 3x8 bits rgb color + 8 bit alpha-channel
+ # "basn6a16", # 3x16 bits rgb color + 16 bit alpha-channel
+
+ # Interlaced
+ # "basi0g01", # black & white
+ # "basi0g02", # 2 bit (4 level) grayscale
+ # "basi0g04", # 4 bit (16 level) grayscale
+ # "basi0g08", # 8 bit (256 level) grayscale
+ # "basi0g16", # 16 bit (64k level) grayscale
+ # "basi2c08", # 3x8 bits rgb color
+ # "basi2c16", # 3x16 bits rgb color
+ # "basi3p01", # 1 bit (2 color) paletted
+ # "basi3p02", # 2 bit (4 color) paletted
+ # "basi3p04", # 4 bit (16 color) paletted
+ # "basi3p08", # 8 bit (256 color) paletted
+ # "basi4a08", # 8 bit grayscale + 8 bit alpha-channel
+ # "basi4a16", # 16 bit grayscale + 16 bit alpha-channel
+ # "basi6a08", # 3x8 bits rgb color + 8 bit alpha-channel
+ # "basi6a16", # 3x16 bits rgb color + 16 bit alpha-channel
+
+ # Odd sizes
+ # "s01i3p01", # 1x1 paletted file, interlaced
+ "s01n3p01", # 1x1 paletted file, no interlacing
+ # "s02i3p01", # 2x2 paletted file, interlaced
+ "s02n3p01", # 2x2 paletted file, no interlacing
+ # "s03i3p01", # 3x3 paletted file, interlaced
+ "s03n3p01", # 3x3 paletted file, no interlacing
+ # "s04i3p01", # 4x4 paletted file, interlaced
+ "s04n3p01", # 4x4 paletted file, no interlacing
+ # "s05i3p02", # 5x5 paletted file, interlaced
+ "s05n3p02", # 5x5 paletted file, no interlacing
+ # "s06i3p02", # 6x6 paletted file, interlaced
+ "s06n3p02", # 6x6 paletted file, no interlacing
+ # "s07i3p02", # 7x7 paletted file, interlaced
+ "s07n3p02", # 7x7 paletted file, no interlacing
+ # "s08i3p02", # 8x8 paletted file, interlaced
+ "s08n3p02", # 8x8 paletted file, no interlacing
+ # "s09i3p02", # 9x9 paletted file, interlaced
+ "s09n3p02", # 9x9 paletted file, no interlacing
+ # "s32i3p04", # 32x32 paletted file, interlaced
+ "s32n3p04", # 32x32 paletted file, no interlacing
+ # "s33i3p04", # 33x33 paletted file, interlaced
+ "s33n3p04", # 33x33 paletted file, no interlacing
+ # "s34i3p04", # 34x34 paletted file, interlaced
+ "s34n3p04", # 34x34 paletted file, no interlacing
+ # "s35i3p04", # 35x35 paletted file, interlaced
+ "s35n3p04", # 35x35 paletted file, no interlacing
+ # "s36i3p04", # 36x36 paletted file, interlaced
+ "s36n3p04", # 36x36 paletted file, no interlacing
+ # "s37i3p04", # 37x37 paletted file, interlaced
+ "s37n3p04", # 37x37 paletted file, no interlacing
+ # "s38i3p04", # 38x38 paletted file, interlaced
+ "s38n3p04", # 38x38 paletted file, no interlacing
+ # "s39i3p04", # 39x39 paletted file, interlaced
+ "s39n3p04", # 39x39 paletted file, no interlacing
+ # "s40i3p04", # 40x40 paletted file, interlaced
+ "s40n3p04", # 40x40 paletted file, no interlacing
+]
diff --git a/tests/test_png.nim b/tests/test_png.nim
new file mode 100644
index 0000000..5ad64fe
--- /dev/null
+++ b/tests/test_png.nim
@@ -0,0 +1,22 @@
+import pixie/fileformats/png, strformat, pngsuite
+
+for file in pngSuiteFiles:
+ let
+ original = cast[seq[uint8]](readFile(&"tests/data/pngsuite/{file}.png"))
+ decoded = decodePng(original)
+ encoded = encodePng(decoded)
+ decoded2 = decodePng(cast[seq[uint8]](encoded))
+
+ doAssert decoded.height == decoded2.height
+ doAssert decoded.width == decoded2.width
+ doAssert decoded.data == decoded2.data
+
+for channels in 1 .. 4:
+ var data: seq[uint8]
+ for x in 0 ..< 16:
+ for y in 0 ..< 16:
+ var components = newSeq[uint8](channels)
+ for i in 0 ..< channels:
+ components[i] = (x * 16).uint8
+ data.add(components)
+ let encoded = encodePng(16, 16, channels, data[0].addr, data.len)
diff --git a/tests/validate_png.nim b/tests/validate_png.nim
new file mode 100644
index 0000000..4acc22a
--- /dev/null
+++ b/tests/validate_png.nim
@@ -0,0 +1,32 @@
+import chroma, pixie/fileformats/png, stb_image/read as stbi, strformat, pngsuite
+
+for file in pngSuiteFiles:
+ let
+ data = readFile(&"tests/data/pngsuite/{file}.png")
+ pixieLoaded = decodePng(cast[seq[uint8]](data))
+
+ var
+ width, height, channels: int
+ stbiLoadedData = loadFromMemory(
+ cast[seq[byte]](data),
+ width,
+ height,
+ channels,
+ stbi.RGBA
+ )
+ stbiLoadedRGBA: seq[ColorRGBA]
+
+ var i: int
+ while i < stbiLoadedData.len:
+ stbiLoadedRGBA.add(ColorRGBA(
+ r: stbiLoadedData[i + 0],
+ g: stbiLoadedData[i + 1],
+ b: stbiLoadedData[i + 2],
+ a: stbiLoadedData[i + 3]
+ ))
+ i += 4
+
+ doAssert pixieLoaded.width == width
+ doAssert pixieLoaded.height == height
+ doAssert pixieLoaded.data.len == stbiLoadedRGBA.len
+ doAssert pixieLoaded.data == stbiLoadedRGBA