Move blends. Better Draw.

src/pixie.nim

@@ -1,7 +1,7 @@
 ## Public interface to you library.
 
 import pixie/images, pixie/masks, pixie/paths, pixie/common, pixie/blends,
-  pixie/fileformats/bmp, pixie/fileformats/png, flatty/binny
+  pixie/fileformats/bmp, pixie/fileformats/png, flatty/binny, os
 
 export images, masks, paths, PixieError, blends
 
@@ -46,3 +46,11 @@ proc encodeImage*(image: Image, fileFormat: FileFormat): string =
 proc writeFile*(image: Image, filePath: string, fileFormat: FileFormat) =
   ## Writes an image to a file.
   writeFile(filePath, image.encodeImage(fileFormat))
+
+proc writeFile*(image: Image, filePath: string) =
+  ## Writes an image to a file.
+  let fileFormat = case splitFile(filePath).ext:
+    of "png": ffPng
+    of "bmp": ffBmp
+    else: ffPng
+  writeFile(filePath, image.encodeImage(fileFormat))

src/pixie/blends.nim

@@ -100,7 +100,7 @@ proc mix*(blendMode: BlendMode, target, blend: Color): Color =
     result.a = target.a * (1 - blend.a)
     return
   elif blendMode == Copy:
-    result = target
+    result = blend
     return
 
   proc multiply(Cb, Cs: float32): float32 =

src/pixie/images.nim

@@ -24,7 +24,13 @@ proc `$`*(image: Image): string =
 
 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
+  x >= 0 and x < image.width and
+  y >= 0 and y < image.height
+
+proc inside1px*(image: Image, x, y: float): bool {.inline.} =
+  ## Returns true if (x, y) is inside the image.
+  x >= -1 and x < (image.width.float32 + 1) and
+  y >= -1 and y < (image.height.float32 + 1)
 
 proc getRgbaUnsafe*(image: Image, x, y: int): ColorRGBA {.inline.} =
   ## Gets a color from (x, y) coordinates.
@@ -102,45 +108,24 @@ proc magnifyBy2*(image: Image, scale2x: int): Image =
 proc magnifyBy2*(image: Image): Image =
   image.magnifyBy2(2)
 
-func moduloMod(n, M: int): int {.inline.} =
-  ## Computes "mathematical" modulo vs c modulo.
-  ((n mod M) + M) mod M
-
 func lerp(a, b: Color, v: float): Color {.inline.} =
   result.r = lerp(a.r, b.r, v)
   result.g = lerp(a.g, b.g, v)
   result.b = lerp(a.b, b.b, v)
   result.a = lerp(a.a, b.a, v)
 
-proc getRgbaSmooth*(image: Image, x, y: float64): ColorRGBA
-  {.inline, raises: [].} =
+proc getRgbaSmooth*(image: Image, x, y: float64): ColorRGBA {.inline.} =
   ## Gets a pixel as (x, y) floats.
   let
     minX = floor(x).int
     difX = (x - minX.float32)
-
     minY = floor(y).int
     difY = (y - minY.float32)
 
-    vX0Y0 = image.getRgbaUnsafe(
-      moduloMod(minX, image.width),
-      moduloMod(minY, image.height),
-    ).color()
-
-    vX1Y0 = image.getRgbaUnsafe(
-      moduloMod(minX + 1, image.width),
-      moduloMod(minY, image.height),
-    ).color()
-
-    vX0Y1 = image.getRgbaUnsafe(
-      moduloMod(minX, image.width),
-      moduloMod(minY + 1, image.height),
-    ).color()
-
-    vX1Y1 = image.getRgbaUnsafe(
-      moduloMod(minX + 1, image.width),
-      moduloMod(minY + 1, image.height),
-    ).color()
+    vX0Y0 = image[minX, minY].color()
+    vX1Y0 = image[minX + 1, minY].color()
+    vX0Y1 = image[minX, minY + 1].color()
+    vX1Y1 = image[minX + 1, minY + 1].color()
 
     bottomMix = lerp(vX0Y0, vX1Y0, difX)
     topMix = lerp(vX0Y1, vX1Y1, difX)
@@ -165,25 +150,67 @@ func translate*(v: Vec2): Mat3 =
   result[2, 1] = v.y
   result[2, 2] = 1
 
-proc draw*(destImage: Image, srcImage: Image, mat: Mat3, blendMode = Normal): Image =
+proc fraction(v: float32): float32 =
+  result = abs(v)
+  result = result - floor(result)
+
+proc drawFast*(a: Image, b: Image, x, y: int): Image =
+  ## Draws one image onto another using integer x,y offset with COPY.
+  result = newImage(a.width, a.height)
+  for yd in 0 ..< a.width:
+    for xd in 0 ..< a.height:
+      var rgba = a.getRgbaUnsafe(xd, yd)
+      if b.inside(xd + x, yd + y):
+        rgba = b.getRgbaUnsafe(xd + x, yd + y)
+      result.setRgbaUnsafe(xd, yd, rgba)
+
+proc drawFast*(a: Image, b: Image, x, y: int, blendMode: BlendMode): Image =
+  ## Draws one image onto another using integer x,y offset with color blending.
+  result = newImage(a.width, a.height)
+  for yd in 0 ..< a.width:
+    for xd in 0 ..< a.height:
+      var rgba = a.getRgbaUnsafe(xd, yd)
+      if b.inside(xd + x, yd + y):
+        var rgba2 = b.getRgbaUnsafe(xd + x, yd + y)
+        if blendMode.hasEffect(rgba2):
+          rgba = blendMode.mix(rgba, rgba2)
+      result.setRgbaUnsafe(xd, yd, rgba)
+
+proc drawFast*(a: Image, b: Image, mat: Mat3, blendMode: BlendMode): Image =
   ## Draws one image onto another using matrix with color blending.
-
-  # Todo: if matrix is simple integer translation -> fast pass
-  # Todo: if matrix is a simple flip -> fast path
-  # Todo: if blend mode is copy -> fast path
-
-  result = newImage(destImage.width, destImage.height)
-  for y in 0 ..< destImage.width:
-    for x in 0 ..< destImage.height:
+  result = newImage(a.width, a.height)
+  for y in 0 ..< a.width:
+    for x in 0 ..< a.height:
+      var rgba = a.getRgbaUnsafe(x, y)
       let srcPos = mat * vec2(x.float32, y.float32)
-      let destRgba = destImage.getRgbaUnsafe(x, y)
-      var rgba = destRgba
-      var srcRgba = rgba(0, 0, 0, 0)
-      if srcImage.inside(srcPos.x.floor.int, srcPos.y.floor.int):
-        srcRgba = srcImage.getRgbaSmooth(srcPos.x - 0.5, srcPos.y - 0.5)
-      if blendMode.hasEffect(srcRgba):
-        rgba = blendMode.mix(destRgba, srcRgba)
+      if b.inside1px(srcPos.x, srcPos.y):
+        let rgba2 = b.getRgbaSmooth(srcPos.x, srcPos.y)
+        if blendMode.hasEffect(rgba2):
+          rgba = blendMode.mix(rgba, rgba2)
       result.setRgbaUnsafe(x, y, rgba)
 
-proc draw*(destImage: Image, srcImage: Image, pos = vec2(0, 0), blendMode = Normal): Image =
-  destImage.draw(srcImage, translate(-pos), blendMode)
+proc draw*(a: Image, b: Image, mat: Mat3, blendMode = Normal): Image =
+  ## Draws one image onto another using matrix with color blending.
+
+  if mat[0, 0] == 1 and mat[0, 1] == 0 and
+    mat[1, 0] == 0 and mat[1, 1] == 1 and
+    mat[2, 0].fraction == 0.0 and mat[2, 1].fraction == 0.0:
+    # Matrix is simple integer translation fast path:
+    if blendMode == Copy:
+      echo "use 1"
+      return drawFast(
+        a, b, mat[2, 0].int, mat[2, 1].int
+      )
+    else:
+      echo "use 2"
+      return drawFast(
+        a, b, mat[2, 0].int, mat[2, 1].int, blendMode
+      )
+
+  # Todo: if matrix is a simple flip -> fast path
+  echo "use 3"
+  return drawFast(a, b, mat, blendMode)
+
+
+proc draw*(a: Image, b: Image, pos = vec2(0, 0), blendMode = Normal): Image =
+  a.draw(b, translate(-pos), blendMode)

tests/test_images.nim

@@ -1,4 +1,14 @@
-import pixie, chroma
+import pixie, chroma, vmath, os
+
+proc writeAndCheck(image: Image, fileName: string) =
+  image.writeFile(fileName)
+  let masterFileName = fileName.changeFileExt(".master.png")
+  if not existsFile(masterFileName):
+    quit("Master file: " & masterFileName & " not found!")
+  var master = readImage(fileName)
+  assert image.width == master.width
+  assert image.height == master.height
+  assert image.data == master.data
 
 block:
   var image = newImage(10, 10)
@@ -9,3 +19,27 @@ block:
   var image = newImage(10, 10)
   image.fill(rgba(255, 0, 0, 255))
   doAssert image[0, 0] == rgba(255, 0, 0, 255)
+
+block:
+  var a = newImage(100, 100)
+  a.fill(rgba(255, 0, 0, 255))
+  var b = newImage(100, 100)
+  b.fill(rgba(0, 255, 0, 255))
+  var c = a.draw(b, pos=vec2(25, 25))
+  c.writeAndCheck("tests/images/draw.png")
+
+block:
+  var a = newImage(100, 100)
+  a.fill(rgba(255, 0, 0, 255))
+  var b = newImage(100, 100)
+  b.fill(rgba(0, 255, 0, 255))
+  var c = a.draw(b, pos=vec2(25, 25), COPY)
+  c.writeAndCheck("tests/images/drawCopy.png")
+
+block:
+  var a = newImage(100, 100)
+  a.fill(rgba(255, 0, 0, 255))
+  var b = newImage(100, 100)
+  b.fill(rgba(0, 255, 0, 255))
+  var c = a.draw(b, pos=vec2(25.15, 25.15))
+  c.writeAndCheck("tests/images/drawSmooth.png")