From 6a74639498c02701e5c0bb605022c7aa26e1081a Mon Sep 17 00:00:00 2001
From: Ryan Oldenburg <guzba8@gmail.com>
Date: Fri, 20 Nov 2020 22:34:57 -0600
Subject: [PATCH] read, encode, decode, write
---
src/pixie.nim | 34 +++++++++++++++++++++++++++++++++-
src/pixie/fileformats/bmp.nim | 7 +++++--
src/pixie/fileformats/png.nim | 10 ++++++++--
src/pixie/images.nim | 16 ----------------
4 files changed, 46 insertions(+), 21 deletions(-)
diff --git a/src/pixie.nim b/src/pixie.nim
index 9cf7e6a..4494f15 100644
--- a/src/pixie.nim
+++ b/src/pixie.nim
@@ -1,8 +1,14 @@
## Public interface to you library.
-import pixie/images, pixie/masks, pixie/paths, pixie/common
+import pixie/images, pixie/masks, pixie/paths, pixie/common,
+ pixie/fileformats/bmp, pixie/fileformats/png, flatty/binny
+
export images, masks, paths, PixieError
+type
+ FileFormat* = enum
+ ffPng, ffBmp
+
proc toMask*(image: Image): Mask =
## Converts an Image to a Mask.
result = newMask(image.width, image.height)
@@ -14,3 +20,29 @@ proc toImage*(mask: Mask): Image =
result = newImage(mask.width, mask.height)
for i in 0 ..< mask.data.len:
result.data[i].a = mask.data[i]
+
+proc decodeImage(data: string | seq[uint8]): Image =
+ ## Loads an image from a memory.
+ if data.len > 8 and cast[array[8, uint8]](data.readUint64(0)) == pngSignature:
+ return decodePng(data)
+
+ if data.len > 2 and data.readStr(0, 2) == "BM":
+ return decodeBmp(data)
+
+ raise newException(PixieError, "Unsupported image file format")
+
+proc readImage*(filePath: string): Image =
+ ## Loads an image from a file.
+ decodeImage(readFile(filePath))
+
+proc encodeImage(image: Image, fileFormat: FileFormat): string =
+ ## Encodes an image into a memory.
+ case fileFormat:
+ of ffPng:
+ image.encodePng()
+ of ffBmp:
+ image.encodeBmp()
+
+proc writeFile*(image: Image, filePath: string, fileFormat: FileFormat) =
+ ## Writes an image to a file.
+ writeFile(filePath, image.encodeImage(fileFormat))
diff --git a/src/pixie/fileformats/bmp.nim b/src/pixie/fileformats/bmp.nim
index 3a2c9d3..3cafb37 100644
--- a/src/pixie/fileformats/bmp.nim
+++ b/src/pixie/fileformats/bmp.nim
@@ -1,4 +1,4 @@
-import ../images, flatty/binny, chroma, pixie/common
+import flatty/binny, chroma, pixie/common, pixie/images
# See: https://en.wikipedia.org/wiki/BMP_file_format
@@ -6,7 +6,7 @@ proc decodeBmp*(data: string): Image =
## Decodes bitmap data into an Image.
# BMP Header
- if data[0..1] != "BM":
+ if data[0 .. 1] != "BM":
raise newException(PixieError, "Invalid BMP data")
let
@@ -46,6 +46,9 @@ proc decodeBmp*(data: string): Image =
offset += 3
result[x, result.height - y - 1] = rgba
+proc decodeBmp*(data: seq[uint8]): Image {.inline.} =
+ decodeBmp(cast[string](data))
+
proc encodeBmp*(image: Image): string =
## Encodes an image into the BMP file format.
diff --git a/src/pixie/fileformats/png.nim b/src/pixie/fileformats/png.nim
index 63bec8e..d0c3827 100644
--- a/src/pixie/fileformats/png.nim
+++ b/src/pixie/fileformats/png.nim
@@ -1,7 +1,10 @@
-import chroma, pixie/images, pixie/common, math, zippy, zippy/crc, flatty/binny
+import chroma, pixie/common, math, zippy, zippy/crc, flatty/binny, pixie/images
# See http://www.libpng.org/pub/png/spec/1.2/PNG-Contents.html
+const
+ pngSignature* = [137.uint8, 80, 78, 71, 13, 10, 26, 10]
+
type
ChunkCounts = object
PLTE, IDAT: uint8
@@ -286,7 +289,7 @@ proc decodePng*(data: seq[uint8]): Image =
# PNG file signature
let signature = cast[array[8, uint8]](data.readUint64(0))
- if signature != [137.uint8, 80, 78, 71, 13, 10, 26, 10]:
+ if signature != pngSignature:
failInvalid()
var
@@ -371,6 +374,9 @@ proc decodePng*(data: seq[uint8]): Image =
result.height = header.height
result.data = parseImageData(header, palette, imageData)
+proc decodePng*(data: string): Image {.inline.} =
+ decodePng(cast[seq[uint8]](data))
+
proc encodePng*(
width, height, channels: int, data: pointer, len: int
): seq[uint8] =
diff --git a/src/pixie/images.nim b/src/pixie/images.nim
index 5492cc7..d9ec0d1 100644
--- a/src/pixie/images.nim
+++ b/src/pixie/images.nim
@@ -22,22 +22,6 @@ proc `$`*(image: Image): string =
## Display the image size and channels.
"<Image " & $image.width & "x" & $image.height & ">"
-proc decodeImage(data: seq[uint8]): Image =
- ## Loads an image from a memory.
- discard
-
-proc readImage*(filePath: string): Image =
- ## Loads an image from a file.
- discard
-
-proc encodeImage(image: Image): seq[uint8] =
- ## Encodes an image into a memory.
- discard
-
-proc writeFile*(image: Image, filePath: string): Image =
- ## Writes an image to a file.
- discard
-
proc inside*(image: Image, x, y: int): bool {.inline.} =
## Returns true if (x, y) is inside the image.
x >= 0 and x < image.width and y >= 0 and y < image.height