Merge pull request #236 from treeform/drawImage

Add drawImage to context.

src/pixie/contexts.nim

@@ -589,3 +589,47 @@ proc strokePolygon*(ctx: Context, pos: Vec2, size: float32, sides: int) =
   var path: Path
   path.polygon(pos, size, sides)
   ctx.stroke(path)
+
+proc drawImage*(ctx: Context, image: Image, dx, dy, dWidth, dHeight: float32) =
+  ## Draws a source image onto the destination image.
+  var
+    imageMat = ctx.mat * translate(vec2(dx, dy)) * scale(vec2(
+      dWidth / image.width.float32,
+      dHeight / image.height.float32
+    ))
+    savedStyle = ctx.fillStyle
+  ctx.fillStyle = Paint(kind: pkImage, image: image, imageMat: imageMat)
+  var path: Path
+  path.rect(rect(dx, dy, dWidth, dHeight))
+  ctx.fill(path)
+  ctx.fillStyle = savedStyle
+
+proc drawImage*(ctx: Context, image: Image, dx, dy: float32) =
+  ## Draws a source image onto the destination image.
+  ctx.drawImage(image, dx, dx, image.width.float32, image.height.float32)
+
+proc drawImage*(ctx: Context, image: Image, pos: Vec2) =
+  ## Draws a source image onto the destination image.
+  ctx.drawImage(image, pos.x, pos.y)
+
+proc drawImage*(ctx: Context, image: Image, rect: Rect) =
+  ## Draws a source image onto the destination image.
+  ctx.drawImage(image, rect.x, rect.y, rect.w, rect.h)
+
+proc drawImage*(
+  ctx: Context,
+  image: Image,
+  sx, sy, sWidth, sHeight,
+  dx, dy, dWidth, dHeight: float32
+) =
+  ## Draws a source image onto the destination image.
+  var image = image.subImage(sx.int, sy.int, sWidth.int, sHeight.int)
+  ctx.drawImage(image, dx, dx, image.width.float32, image.height.float32)
+
+proc drawImage*(ctx: Context, image: Image, src, dest: Rect) =
+  ## Draws a source image onto the destination image.
+  ctx.drawImage(
+    image,
+    src.x, src.y, src.w, src.h,
+    dest.x, dest.y, dest.w, dest.h
+  )

src/pixie/demo.nim

@@ -1,4 +1,4 @@
-import opengl, pixie, pixie/context
+import opengl, pixie, pixie/contexts
 
 export pixie
 

tests/test_contexts.nim

@@ -548,3 +548,57 @@ block:
   ctx.fillRect(50, 50, 100, 100)
 
   image.writeFile("tests/images/context/globalAlpha_1.png")
+
+block:
+  let
+    image = newImage(100, 100)
+    ctx = newContext(image)
+    testImage = readImage("tests/images/pip1.png")
+  ctx.drawImage(testImage, 0, 0)
+  ctx.drawImage(testImage, 30, 30)
+  image.writeFile("tests/images/context/draw_image.png")
+
+block:
+  let
+    image = newImage(100, 100)
+    ctx = newContext(image)
+    testImage = readImage("tests/images/pip1.png")
+  ctx.translate(30, 30)
+  ctx.drawImage(testImage, -30, -30)
+  ctx.drawImage(testImage, 0, 0)
+  image.writeFile("tests/images/context/draw_image_translated.png")
+
+block:
+  let
+    image = newImage(100, 100)
+    ctx = newContext(image)
+    testImage = readImage("tests/images/pip1.png")
+  ctx.scale(2, 2)
+  ctx.drawImage(testImage, 0, 0)
+  ctx.scale(0.25, 0.25)
+  ctx.drawImage(testImage, 0, 0)
+  image.writeFile("tests/images/context/draw_image_scaled.png")
+
+block:
+  let
+    image = newImage(100, 100)
+    ctx = newContext(image)
+    testImage = readImage("tests/images/pip1.png")
+  ctx.drawImage(testImage, 30, 30, 20, 20)
+  image.writeFile("tests/images/context/draw_image_self_scaled.png")
+
+block:
+  let
+    image = newImage(300, 227)
+    ctx = newContext(image)
+    rhino = readImage("tests/images/rhino.png")
+  ctx.drawImage(rhino, 33, 71, 104, 124, 21, 20, 87, 104);
+  image.writeFile("tests/images/context/draw_image_rhino.png")
+
+block:
+  let
+    image = newImage(300, 227)
+    ctx = newContext(image)
+    rhino = readImage("tests/images/rhino.png")
+  ctx.drawImage(rhino, rect(33, 71, 104, 124), rect(21, 20, 87, 104));
+  image.writeFile("tests/images/context/draw_image_rhino2.png")