Merge pull request #310 from guzba/master

3.0.1, minifyBy2 fix for non-even src dimens

pixie.nimble

@@ -1,4 +1,4 @@
-version     = "3.0.0"
+version     = "3.0.1"
 author      = "Andre von Houck and Ryan Oldenburg"
 description = "Full-featured 2d graphics library for Nim."
 license     = "MIT"
@@ -6,7 +6,7 @@ license     = "MIT"
 srcDir = "src"
 
 requires "nim >= 1.4.0"
-requires "vmath >= 1.0.11"
+requires "vmath >= 1.1.0"
 requires "chroma >= 0.2.5"
 requires "zippy >= 0.6.2"
 requires "flatty >= 0.2.2"

src/pixie/images.nim

@@ -256,14 +256,24 @@ proc minifyBy2*(image: Image, power = 1): Image {.raises: [PixieError].} =
 
   var src = image
   for _ in 1 .. power:
-    result = newImage(src.width div 2, src.height div 2)
+    # When minifying an image of odd size, round the result image size up
-    for y in 0 ..< result.height:
+    # so a 99 x 99 src image returns a 50 x 50 image.
+    let
+      srcWidthIsOdd = (src.width mod 2) != 0
+      srcHeightIsOdd = (src.height mod 2) != 0
+      resultEvenWidth = src.width div 2
+      resultEvenHeight = src.height div 2
+    result = newImage(
+      if srcWidthIsOdd: resultEvenWidth + 1 else: resultEvenWidth,
+      if srcHeightIsOdd: resultEvenHeight + 1 else: resultEvenHeight
+    )
+    for y in 0 ..< resultEvenHeight:
       var x: int
       when defined(amd64) and not defined(pixieNoSimd):
         let
           oddMask = mm_set1_epi16(cast[int16](0xff00))
           first32 = cast[M128i]([uint32.high, 0, 0, 0])
-        for _ in countup(0, result.width - 4, 2):
+        for _ in countup(0, resultEvenWidth - 4, 2):
           let
             top = mm_loadu_si128(src.data[src.dataIndex(x * 2, y * 2 + 0)].addr)
             btm = mm_loadu_si128(src.data[src.dataIndex(x * 2, y * 2 + 1)].addr)
@@ -303,7 +313,7 @@ proc minifyBy2*(image: Image, power = 1): Image {.raises: [PixieError].} =
           mm_storeu_si128(result.data[result.dataIndex(x, y)].addr, zeroTwo)
           x += 2
 
-      for x in x ..< result.width:
+      for x in x ..< resultEvenWidth:
         let
           a = src.getRgbaUnsafe(x * 2 + 0, y * 2 + 0)
           b = src.getRgbaUnsafe(x * 2 + 1, y * 2 + 0)
@@ -318,6 +328,32 @@ proc minifyBy2*(image: Image, power = 1): Image {.raises: [PixieError].} =
 
         result.setRgbaUnsafe(x, y, rgba)
 
+      if srcWidthIsOdd:
+        let rgbx = mix(
+          src.getRgbaUnsafe(src.width - 1, y * 2 + 0),
+          src.getRgbaUnsafe(src.width - 1, y * 2 + 1),
+          0.5
+        ) * 0.5
+        result.setRgbaUnsafe(result.width - 1, y, rgbx)
+
+    if srcHeightIsOdd:
+      let y = result.height - 1
+
+      for x in 0 ..< resultEvenWidth:
+        let rgbx = mix(
+          src.getRgbaUnsafe(x * 2 + 0, y),
+          src.getRgbaUnsafe(x * 2 + 1, y),
+          0.5
+        ) * 0.5
+        result.setRgbaUnsafe(x, y, rgbx)
+
+      if srcWidthIsOdd:
+        result.setRgbaUnsafe(
+          result.width - 1,
+          result.height - 1,
+          src.getRgbaUnsafe(src.width - 1, src.height - 1) * 0.25
+        )
+
     # Set src as this result for if we do another power
     src = result
 

src/pixie/internal.nim

@@ -22,7 +22,7 @@ proc gaussianKernel*(radius: int): seq[uint16] {.raises: [].} =
   for i, f in floats:
     result[i] = round(f * 255 * 256).uint16
 
-proc applyOpacity*(color: ColorRGBX, opacity: float32): ColorRGBX {.raises: [].} =
+proc `*`*(color: ColorRGBX, opacity: float32): ColorRGBX {.raises: [].} =
   if opacity == 0:
     rgbx(0, 0, 0, 0)
   else:

tests/test_images_draw.nim

@@ -1,5 +1,13 @@
 import pixie, strformat
 
+proc doDiff(rendered: Image, name: string) =
+  rendered.writeFile(&"tests/images/rendered/{name}.png")
+  let
+    master = readImage(&"tests/images/masters/{name}.png")
+    (diffScore, diffImage) = diff(master, rendered)
+  echo &"{name} score: {diffScore}"
+  diffImage.writeFile(&"tests/images/diffs/{name}.png")
+
 block:
   let
     a = newImage(1000, 1000)
@@ -128,14 +136,6 @@ block:
   a.draw(b, translate(vec2(250, 250)) * scale(vec2(0.5, 0.5)))
   a.writeFile("tests/images/scaleHalf.png")
 
-proc doDiff(rendered: Image, name: string) =
-  rendered.writeFile(&"tests/images/rendered/{name}.png")
-  let
-    master = readImage(&"tests/images/masters/{name}.png")
-    (diffScore, diffImage) = diff(master, rendered)
-  echo &"{name} score: {diffScore}"
-  diffImage.writeFile(&"tests/images/diffs/{name}.png")
-
 block:
   let
     a = newImage(100, 100)
@@ -249,3 +249,12 @@ block:
   a.draw(b, m * translate(vec2(-40,-40)))
   a.draw(b, m * translate(vec2(0,-40)))
   doDiff(a, "smooth12")
+
+block:
+  let
+    a = newImage(100, 100)
+    b = newImage(99, 99)
+  a.fill(rgba(255, 255, 255, 255))
+  b.fill(rgba(0, 0, 0, 255))
+  a.draw(b, scale(vec2(0.5, 0.5)))
+  doDiff(a, "minify_odd")