Add image drawing support (#14)

This PR adds basic wrapping of the blContextBlitImageD and blContextBlitScaledImageD functions.

Author: jwiggins

.gitignore

@@ -9,3 +9,4 @@ __pycache__/
 blend2d/*.so
 src/*.c
 *.py[cd]
+*.png

examples/image.py

@@ -0,0 +1,40 @@
+import blend2d
+import numpy as np
+from skimage.io import imsave
+
+
+def random_lines(context, width, height):
+    xs = np.random.randint(0, high=width, size=(100, 2))
+    ys = np.random.randint(0, high=height, size=(100, 2))
+    colors = np.random.random_sample(size=(100, 3))
+
+    context.set_fill_style((1.0, 1.0, 1.0))
+    context.fill_all()
+
+    path = blend2d.Path()
+    for (x0, x1), (y0, y1), color in zip(xs, ys, colors):
+        context.set_stroke_style(color)
+        path.reset()
+        path.move_to(x0, y0)
+        path.line_to(x1, y1)
+        context.stroke_path(path)
+
+
+if __name__ == '__main__':
+    image_array = np.empty((256, 256, 4), dtype=np.uint8)
+    image = blend2d.Image(image_array)
+    image_context = blend2d.Context(image)
+    random_lines(image_context, 256, 256)
+
+    array = np.empty((512, 512, 4), dtype=np.uint8)
+    context = blend2d.Context(blend2d.Image(array))
+    context.clear()
+
+    src = blend2d.Rect(0, 0, *image_array.shape[:2])
+    dst = blend2d.Rect(0, 0, 100, 100)
+    context.blit_scaled_image(dst, image, src)
+
+    context.rotate(-np.pi/12)
+    context.blit_image((10.0, 100.0), image, src)
+
+    imsave('image.png', array)

src/context.pxi

@@ -244,6 +244,24 @@ cdef class Context:
     def set_stroke_width(self, float width):
         _capi.blContextSetStrokeWidth(&self._self, width)
 
+    def blit_image(self, position, Image img, Rect img_area):
+        cdef:
+            _capi.BLPoint point
+            _capi.BLRectI rect
+
+        point.x = position[0]; point.y = position[1]
+        rect.x = <int>img_area._self.x; rect.y = <int>img_area._self.y
+        rect.w = <int>img_area._self.w; rect.h = <int>img_area._self.h
+        _capi.blContextBlitImageD(&self._self, &point, &img._self, &rect)
+
+    def blit_scaled_image(self, Rect rect, Image img, Rect img_area):
+        cdef:
+            _capi.BLRectI dst_rect
+
+        dst_rect.x = <int>img_area._self.x; dst_rect.y = <int>img_area._self.y
+        dst_rect.w = <int>img_area._self.w; dst_rect.h = <int>img_area._self.h
+        _capi.blContextBlitScaledImageD(&self._self, &rect._self, &img._self, &dst_rect)
+
     def fill_all(self):
         _capi.blContextFillAll(&self._self)