feat: add meme rotate_3d (#98)

meme_generator/memes/rotate_3d/__init__.py

@@ -0,0 +1,71 @@
+from typing import List
+
+import numpy as np
+from pil_utils import BuildImage
+
+from meme_generator import add_meme
+from meme_generator.utils import FrameAlignPolicy, Maker, make_gif_or_combined_gif
+
+
+def rotate_3d(images: List[BuildImage], texts, args):
+    tmp_img = images[0].convert("RGBA")
+    fov = 45 * np.pi / 180
+    z = np.sqrt(tmp_img.width**2 + tmp_img.height**2) / 2 / np.tan(fov / 2)
+    w = round(tmp_img.width * 1.2)
+    h = round(tmp_img.height * 1.5)
+    bg = BuildImage.new("RGBA", (w, h))
+
+    def rotate_y(img: BuildImage, theta: float) -> BuildImage:
+        mat = np.array(
+            [
+                [np.cos(theta), 0, np.sin(theta)],
+                [0, 1, 0],
+                [-np.sin(theta), 0, np.cos(theta)],
+            ]
+        )
+        pc = np.array([img.width / 2, img.height / 2, 0])
+        orgs = [
+            np.array([0, 0, 0]),
+            np.array([img.width, 0, 0]),
+            np.array([img.width, img.height, 0]),
+            np.array([0, img.height, 0]),
+        ]
+        dsts = []
+        for i in range(4):
+            dst = mat.dot(orgs[i] - pc)
+            dsts.append(
+                [
+                    dst[0] * z / (z - dst[2]) + pc[0],
+                    dst[1] * z / (z - dst[2]) + pc[1],
+                ]
+            )
+        min_x = min(dsts, key=lambda x: x[0])[0]
+        min_y = min(dsts, key=lambda x: x[1])[1]
+        for i in range(4):
+            dsts[i][0] -= min_x
+            dsts[i][1] -= min_y
+        return img.perspective(tuple(dsts))
+
+    def maker(i: int) -> Maker:
+        def make(img: BuildImage) -> BuildImage:
+            img = img.convert("RGBA")
+            frame = bg.copy()
+            rotated = rotate_y(img, i * 12 * np.pi / 180)
+            frame.paste(
+                rotated,
+                (
+                    round((bg.width - rotated.width) / 2),
+                    round((bg.height - rotated.height) / 2),
+                ),
+                alpha=True,
+            )
+            return frame
+
+        return make
+
+    return make_gif_or_combined_gif(
+        images[0], maker, 30, 0.07, FrameAlignPolicy.extend_loop
+    )
+
+
+add_meme("rotate_3d", rotate_3d, min_images=1, max_images=1, keywords=["三维旋转"])