Use the new vmath v3 with CCW angles.

pixie.nimble

@@ -1,12 +1,12 @@
-version     = "5.1.0"
+version     = "6.0.0"
 author      = "Andre von Houck and Ryan Oldenburg"
 description = "Full-featured 2d graphics library for Nim."
 license     = "MIT"
 
 srcDir = "src"
 
 requires "nim >= 1.4.8"
-requires "vmath >= 1.1.4"
+requires "vmath >= 3.0.0"
 requires "chroma >= 0.2.6"
 requires "zippy >= 0.10.3"
 requires "flatty >= 0.3.4"

src/pixie/contexts.nim

@@ -551,7 +551,7 @@ proc scale*(ctx: Context, x, y: float32) {.inline, raises: [].} =
 
 proc rotate*(ctx: Context, angle: float32) {.inline, raises: [].} =
   ## Adds a rotation to the transformation matrix.
-  ctx.mat = ctx.mat * rotate(-angle)
+  ctx.mat = ctx.mat * rotate(angle)
 
 proc resetTransform*(ctx: Context) {.inline, raises: [].} =
   ## Resets the current transform to the identity matrix.

src/pixie/fileformats/svg.nim

@@ -277,7 +277,7 @@ proc parseSvgProperties(node: XmlNode, inherited: SvgProperties): SvgProperties
       elif f.startsWith("rotate("):
         let
           values = splitArgs(f[7 .. ^2])
-          angle: float32 = parseFloat(values[0]) * -PI / 180
+          angle: float32 = parseFloat(values[0]) * PI / 180
         var cx, cy: float32
         if values.len > 1:
           cx = parseFloat(values[1])

src/pixie/paints.nim

@@ -198,7 +198,7 @@ proc fillGradientRadial(image: Image, paint: Paint) =
     gradientAngle = normalize(center - edge).angle().fixAngle()
     mat = (
       translate(center) *
-      rotate(-gradientAngle) *
+      rotate(gradientAngle) *
       scale(vec2(distanceX, distanceY))
     ).inverse()
   for y in 0 ..< image.height:

src/pixie/paths.nim

@@ -839,7 +839,7 @@ proc commandsToShapes(
 
       ArcParams(
         radii: radii,
-        rotMat: rotate(-radians),
+        rotMat: rotate(radians),
         center: center,
         theta: theta,
         delta: delta

tests/test_images_draw.nim

@@ -17,7 +17,7 @@ block:
   a.fill(rgba(255, 0, 0, 255))
   b.fill(rgba(0, 255, 0, 255))
 
-  a.draw(b, translate(vec2(250, 250)) * rotate(90 * PI.float32 / 180))
+  a.draw(b, translate(vec2(250, 250)) * rotate(-90 * PI.float32 / 180))
   a.xray("tests/images/rotate90.png")
 
 block:
@@ -27,7 +27,7 @@ block:
   a.fill(rgba(255, 0, 0, 255))
   b.fill(rgba(0, 255, 0, 255))
 
-  a.draw(b, translate(vec2(250, 250)) * rotate(180 * PI.float32 / 180))
+  a.draw(b, translate(vec2(250, 250)) * rotate(-180 * PI.float32 / 180))
   a.xray("tests/images/rotate180.png")
 
 block:
@@ -37,7 +37,7 @@ block:
   a.fill(rgba(255, 0, 0, 255))
   b.fill(rgba(0, 255, 0, 255))
 
-  a.draw(b, translate(vec2(250, 250)) * rotate(270 * PI.float32 / 180))
+  a.draw(b, translate(vec2(250, 250)) * rotate(-270 * PI.float32 / 180))
   a.xray("tests/images/rotate270.png")
 
 block:
@@ -47,7 +47,7 @@ block:
   a.fill(rgba(255, 0, 0, 255))
   b.fill(rgba(0, 255, 0, 255))
 
-  a.draw(b, translate(vec2(250, 250)) * rotate(360 * PI.float32 / 180))
+  a.draw(b, translate(vec2(250, 250)) * rotate(-360 * PI.float32 / 180))
   a.xray("tests/images/rotate360.png")
 
 block:
@@ -143,7 +143,7 @@ block:
     b = newImage(50, 50)
   a.fill(rgba(255, 255, 255, 255))
   b.fill(rgbx(0, 0, 0, 255))
-  a.draw(b, translate(vec2(0, 50)) * rotate(45.toRadians))
+  a.draw(b, translate(vec2(0, 50)) * rotate(-45.toRadians))
   a.xray("tests/images/masters/smooth2.png")
 
 block:
@@ -170,7 +170,7 @@ block:
     b = newImage(10, 10)
   a.fill(rgba(255, 255, 255, 255))
   b.fill(rgbx(255, 0, 0, 255))
-  let m = translate(vec2(50, 50)) * rotate(30.toRadians)
+  let m = translate(vec2(50, 50)) * rotate(-30.toRadians)
   a.draw(b, m)
   a.xray("tests/images/masters/smooth5.png")
 
@@ -179,7 +179,7 @@ block:
     a = newImage(100, 100)
     b = readImage(&"tests/images/turtle.png")
   a.fill(rgba(255, 255, 255, 255))
-  let m = translate(vec2(50, 50)) * rotate(30.toRadians)
+  let m = translate(vec2(50, 50)) * rotate(-30.toRadians)
   a.draw(b, m)
   a.xray("tests/images/masters/smooth6.png")
 
@@ -188,7 +188,7 @@ block:
     a = newImage(100, 100)
     b = readImage(&"tests/images/turtle@10x.png")
   a.fill(rgba(255, 255, 255, 255))
-  let m = translate(vec2(50, 50)) * rotate(30.toRadians) * scale(vec2(0.1, 0.1))
+  let m = translate(vec2(50, 50)) * rotate(-30.toRadians) * scale(vec2(0.1, 0.1))
   a.draw(b, m)
   a.xray("tests/images/masters/smooth7.png")
 
@@ -225,7 +225,7 @@ block:
     b = readImage(&"tests/images/turtle.png")
   a.fill(rgba(255, 255, 255, 255))
   let m = translate(vec2(-43.29, -103.87)) *
-    rotate(-15.toRadians) *
+    rotate(15.toRadians) *
     scale(vec2(263.86/40, 263.86/40))
   a.draw(b, m)
   a.xray("tests/images/masters/smooth11.png")
@@ -235,7 +235,7 @@ block:
     a = newImage(100, 100)
     b = readImage(&"tests/images/turtle.png")
   a.fill(rgba(255, 255, 255, 255))
-  let m = translate(vec2(50, 50)) * rotate(-5.toRadians)
+  let m = translate(vec2(50, 50)) * rotate(5.toRadians)
   a.draw(b, m * translate(vec2(0, 0)))
   a.draw(b, m * translate(vec2(-40, 0)))
   a.draw(b, m * translate(vec2(-40, -40)))