Initial commit

geom/demos/aabb.py

@@ -0,0 +1,85 @@
+from pygame import draw, mouse
+from .. import text
+from ..geom.rect import Rect
+from .. import WIDTH, HEIGHT, text
+from ..colors import *
+from ..math import *
+
+class AABBDistance:
+
+    title = "AABB Distance"
+
+    def render(self, surface):
+        rect_a = Rect(
+            WIDTH / 2 - (WIDTH / 8),
+            HEIGHT / 2 - (HEIGHT / 8),
+            WIDTH / 4,
+            HEIGHT / 4,
+        )
+        rect_b = Rect(
+            *mouse.get_pos(),
+            WIDTH / 5,
+            HEIGHT / 5
+        )
+
+        # cx, cy = center
+        dist_x = abs(rect_b.cx - rect_a.cx)
+        dist_y = abs(rect_b.cy - rect_a.cy)
+
+        gap_x = dist_x - rect_a.halfwidth - rect_b.halfwidth
+        gap_y = dist_y - rect_a.halfheight - rect_b.halfheight
+
+        distance = 0
+
+        if gap_x < 0 and gap_y < 0:
+            distance = max(gap_x, gap_y)
+        else:
+            if gap_x < 0:
+                distance = gap_y
+            elif gap_y < 0:
+                distance = gap_x
+            else:
+                distance = length(gap_x, gap_y)
+
+        text.draw(surface, (10, HEIGHT - 20), WHITE, f"Distance: {distance}")
+        rect_a.draw(surface, YELLOW, 4)
+        rect_b.draw(surface, WHITE, 4)
+        draw.line(surface, RED if distance < 0 else GREEN,
+                  rect_a.get_center(), rect_b.get_center(), 2)
+
+class PointAABBDistance:
+
+    title = "Point-AABB Distance"
+
+    def render(self, surface):
+        rect_a = Rect(
+            WIDTH / 2 - (WIDTH / 8),
+            HEIGHT / 2 - (HEIGHT / 8),
+            WIDTH / 4,
+            HEIGHT / 4,
+        )
+        cx, cy = mouse.get_pos()
+
+        # cx, cy = point
+        dist_x = abs(cx - rect_a.cx)
+        dist_y = abs(cy - rect_a.cy)
+
+        gap_x = dist_x - rect_a.halfwidth
+        gap_y = dist_y - rect_a.halfheight
+
+        distance = 0
+
+        if gap_x < 0 and gap_y < 0:
+            distance = max(gap_x, gap_y)
+        else:
+            if gap_x < 0:
+                distance = gap_y
+            elif gap_y < 0:
+                distance = gap_x
+            else:
+                distance = length(gap_x, gap_y)
+
+        text.draw(surface, (10, HEIGHT - 20), WHITE, f"Distance: {distance}")
+        rect_a.draw(surface, YELLOW, 4)
+        draw.line(surface, RED if distance < 0 else GREEN,
+                  rect_a.get_center(), (cx, cy), 2)

geom/demos/vec_proj.py

@@ -0,0 +1,29 @@
+from pygame import draw, mouse
+from .. import HEIGHT, WIDTH
+from ..colors import *
+from ..math import *
+
+class VecProj:
+
+    title = "Vector Projection"
+
+    def render(self, surface):
+        x1 = WIDTH / 4
+        y1 = HEIGHT / 2 + 100
+        x2 = 0.75 * WIDTH
+        y2 = HEIGHT / 2
+
+        cx, cy = mouse.get_pos()
+
+        lx, ly = x2 - x1, y2 - y1           # line vector
+        llen = length(lx, ly)
+        lnx, lny = lx / llen, ly / llen     # line normal
+        lcx, lcy = cx - x1, cy - y1         # line start - cursor vector
+
+        proj = dot(lcx, lcy, lx, ly) / llen
+
+        draw.line(
+            surface, GREEN, (cx, cy), add(x1, y1, *scale(lnx, lny, proj)), 5
+        )
+        draw.line(surface, WHITE, (cx, cy), (x1, y1), 5)
+        draw.line(surface, YELLOW, (x1, y1), (x2, y2), 5)