围绕枢轴旋转和缩放图像，同时在 Pygame 中分别缩放宽度和高度
Rotating and scaling an image around a pivot, while scaling width and height separately in Pygame
我在列表中有一组关键帧，如下所示：
[{
"duration" : 20,
"position" : [0,0],
"scale" : [1, 1],
"angle" : 0,
"rgba" : [255,255,255,255]
},
{
"duration" : 5,
"position" : [0,0],
"scale" : [1, 1.5],
"angle" : 50,
"rgba" : [255,255,255,255]
}]
想法是能够对每一帧进行相应的转换。请注意，比例在宽度和高度之间分开。
问题来自尝试独立缩放宽度和高度，同时仍然围绕一个枢轴旋转。
我尝试修改一些代码：()
def blitRotate(surf, image, pos, originPos, angle, zoom):
# calcaulate the axis aligned bounding box of the rotated image
w, h = image.get_size()
box = [pygame.math.Vector2(p) for p in [(0, 0), (w, 0), (w, -h), (0, -h)]]
box_rotate = [p.rotate(angle) for p in box]
min_box = (min(box_rotate, key=lambda p: p[0])[0], min(box_rotate, key=lambda p: p[1])[1])
max_box = (max(box_rotate, key=lambda p: p[0])[0], max(box_rotate, key=lambda p: p[1])[1])
# calculate the translation of the pivot
pivot = pygame.math.Vector2(originPos[0], -originPos[1])
pivot_rotate = pivot.rotate(angle)
pivot_move = pivot_rotate - pivot
# calculate the upper left origin of the rotated image
move = (-originPos[0] + min_box[0] - pivot_move[0], -originPos[1] - max_box[1] + pivot_move[1])
origin = (pos[0] + zoom * move[0], pos[1] + zoom * move[1])
# get a rotated image
rotozoom_image = pygame.transform.rotozoom(image, angle, zoom)
# rotate and blit the image
surf.blit(rotozoom_image, origin)
# draw rectangle around the image
pygame.draw.rect (surf, (255, 0, 0), (*origin, *rotozoom_image.get_size()),2)
但我正在努力思考使其工作所必需的数学，我尝试将 zoom 分成一个骗局，然后而不是做 rotozoom ，先用 [=14= 缩放] 之后 transform.rotate 但这也没有用。
为了更好地说明我的意思，应该是这样的：
它改变了它的宽度和高度，但枢轴保持不变
我建议采用此处介绍的略有不同的方法：How to set the pivot point (center of rotation) for pygame.transform.rotate()?
调整此算法所需要做的就是按缩放系数缩放从图像中心到图像轴心点的矢量：
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
围绕轴心点旋转图像、缩放和 blits 图像的最终函数可能如下所示：
def blitRotate(surf, original_image, origin, pivot, angle, scale):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
rotozoom_image = pygame.transform.rotozoom(original_image, angle, scale)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
也可以分别为x轴和y轴指定比例因子：
def blitRotate(surf, original_image, origin, pivot, angle, scale_x, scale_y):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot.x *= scale_x
offset_center_to_pivot.y *= scale_y
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
scaled_image = pygame.transform.smoothscale(original_image, (image_rect.width * scale_x, image_rect.height * scale_y))
rotozoom_image = pygame.transform.rotate(scaled_image, angle)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
最小示例： repl.it/@Rabbid76/PyGame-RotateZoomPivot
import pygame
pygame.init()
screen = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()
def blitRotate(surf, original_image, origin, pivot, angle, scale):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
rotozoom_image = pygame.transform.rotozoom(original_image, angle, scale)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
pygame.draw.rect (surf, (255, 0, 0), rect, 2)
try:
image = pygame.image.load('AirPlane.png')
except:
text = pygame.font.SysFont('Times New Roman', 50).render('image', False, (255, 255, 0))
image = pygame.Surface((text.get_width()+1, text.get_height()+1))
pygame.draw.rect(image, (0, 0, 255), (1, 1, *text.get_size()))
image.blit(text, (1, 1))
w, h = image.get_size()
angle, zoom = 0, 1
done = False
while not done:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pos = (screen.get_width()/2, screen.get_height()/2)
screen.fill(0)
blitRotate(screen, image, pos, (w/4, h/2), angle, zoom)
angle += 1
zoom += 0.01
if zoom > 5:
zoom = 1
pygame.draw.line(screen, (0, 255, 0), (pos[0]-20, pos[1]), (pos[0]+20, pos[1]), 3)
pygame.draw.line(screen, (0, 255, 0), (pos[0], pos[1]-20), (pos[0], pos[1]+20), 3)
pygame.draw.circle(screen, (0, 255, 0), pos, 7, 0)
pygame.display.flip()
pygame.quit()
exit()
示例 2： repl.it/@Rabbid76/PyGame-RotateZoomPivot
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 300))
clock = pygame.time.Clock()
def blitRotateZoomXY(surf, original_image, origin, pivot, angle, scale_x, scale_y):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot.x *= scale_x
offset_center_to_pivot.y *= scale_y
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
scaled_image = pygame.transform.smoothscale(original_image, (image_rect.width * scale_x, image_rect.height * scale_y))
rotozoom_image = pygame.transform.rotate(scaled_image, angle)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
cannon = pygame.image.load('icon/cannon.png')
cannon_mount = pygame.image.load('icon/cannon_mount.png')
angle, zoom_x, zoom_y = -90, 1, 1
stage = 0
done = False
while not done:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pos = (screen.get_width()/3, screen.get_height()*3/4)
screen.fill((192, 192, 192))
blitRotateZoomXY(screen, cannon, pos, (33.5, 120), angle, zoom_x, zoom_y)
screen.blit(cannon_mount, (pos[0]-43, pos[1]-16))
pygame.display.flip()
if stage == 0:
angle += 1
if angle >= -30:
stage += 1
elif stage == 1:
zoom_y -= 0.05
if zoom_y <= 0.7:
stage += 1
elif stage == 2:
zoom_y += 0.05
if zoom_y >= 1:
stage += 1
elif stage == 3:
angle -= 1
if angle <= -90:
stage = 0
pygame.quit()
exit()
我在列表中有一组关键帧，如下所示：
[{
"duration" : 20,
"position" : [0,0],
"scale" : [1, 1],
"angle" : 0,
"rgba" : [255,255,255,255]
},
{
"duration" : 5,
"position" : [0,0],
"scale" : [1, 1.5],
"angle" : 50,
"rgba" : [255,255,255,255]
}]
想法是能够对每一帧进行相应的转换。请注意，比例在宽度和高度之间分开。
问题来自尝试独立缩放宽度和高度，同时仍然围绕一个枢轴旋转。
我尝试修改一些代码：(
def blitRotate(surf, image, pos, originPos, angle, zoom):
# calcaulate the axis aligned bounding box of the rotated image
w, h = image.get_size()
box = [pygame.math.Vector2(p) for p in [(0, 0), (w, 0), (w, -h), (0, -h)]]
box_rotate = [p.rotate(angle) for p in box]
min_box = (min(box_rotate, key=lambda p: p[0])[0], min(box_rotate, key=lambda p: p[1])[1])
max_box = (max(box_rotate, key=lambda p: p[0])[0], max(box_rotate, key=lambda p: p[1])[1])
# calculate the translation of the pivot
pivot = pygame.math.Vector2(originPos[0], -originPos[1])
pivot_rotate = pivot.rotate(angle)
pivot_move = pivot_rotate - pivot
# calculate the upper left origin of the rotated image
move = (-originPos[0] + min_box[0] - pivot_move[0], -originPos[1] - max_box[1] + pivot_move[1])
origin = (pos[0] + zoom * move[0], pos[1] + zoom * move[1])
# get a rotated image
rotozoom_image = pygame.transform.rotozoom(image, angle, zoom)
# rotate and blit the image
surf.blit(rotozoom_image, origin)
# draw rectangle around the image
pygame.draw.rect (surf, (255, 0, 0), (*origin, *rotozoom_image.get_size()),2)
但我正在努力思考使其工作所必需的数学，我尝试将 zoom 分成一个骗局，然后而不是做 rotozoom ，先用 [=14= 缩放] 之后 transform.rotate 但这也没有用。
为了更好地说明我的意思，应该是这样的：
它改变了它的宽度和高度，但枢轴保持不变
我建议采用此处介绍的略有不同的方法：How to set the pivot point (center of rotation) for pygame.transform.rotate()?
调整此算法所需要做的就是按缩放系数缩放从图像中心到图像轴心点的矢量：
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
围绕轴心点旋转图像、缩放和 blits 图像的最终函数可能如下所示：
def blitRotate(surf, original_image, origin, pivot, angle, scale):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
rotozoom_image = pygame.transform.rotozoom(original_image, angle, scale)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
也可以分别为x轴和y轴指定比例因子：
def blitRotate(surf, original_image, origin, pivot, angle, scale_x, scale_y):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot.x *= scale_x
offset_center_to_pivot.y *= scale_y
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
scaled_image = pygame.transform.smoothscale(original_image, (image_rect.width * scale_x, image_rect.height * scale_y))
rotozoom_image = pygame.transform.rotate(scaled_image, angle)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
最小示例：
import pygame
pygame.init()
screen = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()
def blitRotate(surf, original_image, origin, pivot, angle, scale):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = (pygame.math.Vector2(origin) - image_rect.center) * scale
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
rotozoom_image = pygame.transform.rotozoom(original_image, angle, scale)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
pygame.draw.rect (surf, (255, 0, 0), rect, 2)
try:
image = pygame.image.load('AirPlane.png')
except:
text = pygame.font.SysFont('Times New Roman', 50).render('image', False, (255, 255, 0))
image = pygame.Surface((text.get_width()+1, text.get_height()+1))
pygame.draw.rect(image, (0, 0, 255), (1, 1, *text.get_size()))
image.blit(text, (1, 1))
w, h = image.get_size()
angle, zoom = 0, 1
done = False
while not done:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pos = (screen.get_width()/2, screen.get_height()/2)
screen.fill(0)
blitRotate(screen, image, pos, (w/4, h/2), angle, zoom)
angle += 1
zoom += 0.01
if zoom > 5:
zoom = 1
pygame.draw.line(screen, (0, 255, 0), (pos[0]-20, pos[1]), (pos[0]+20, pos[1]), 3)
pygame.draw.line(screen, (0, 255, 0), (pos[0], pos[1]-20), (pos[0], pos[1]+20), 3)
pygame.draw.circle(screen, (0, 255, 0), pos, 7, 0)
pygame.display.flip()
pygame.quit()
exit()
示例 2：
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 300))
clock = pygame.time.Clock()
def blitRotateZoomXY(surf, original_image, origin, pivot, angle, scale_x, scale_y):
image_rect = original_image.get_rect(topleft = (origin[0] - pivot[0], origin[1]-pivot[1]))
offset_center_to_pivot = pygame.math.Vector2(origin) - image_rect.center
offset_center_to_pivot.x *= scale_x
offset_center_to_pivot.y *= scale_y
rotated_offset = offset_center_to_pivot.rotate(-angle)
rotated_image_center = (origin[0] - rotated_offset.x, origin[1] - rotated_offset.y)
scaled_image = pygame.transform.smoothscale(original_image, (image_rect.width * scale_x, image_rect.height * scale_y))
rotozoom_image = pygame.transform.rotate(scaled_image, angle)
rect = rotozoom_image.get_rect(center = rotated_image_center)
surf.blit(rotozoom_image, rect)
cannon = pygame.image.load('icon/cannon.png')
cannon_mount = pygame.image.load('icon/cannon_mount.png')
angle, zoom_x, zoom_y = -90, 1, 1
stage = 0
done = False
while not done:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pos = (screen.get_width()/3, screen.get_height()*3/4)
screen.fill((192, 192, 192))
blitRotateZoomXY(screen, cannon, pos, (33.5, 120), angle, zoom_x, zoom_y)
screen.blit(cannon_mount, (pos[0]-43, pos[1]-16))
pygame.display.flip()
if stage == 0:
angle += 1
if angle >= -30:
stage += 1
elif stage == 1:
zoom_y -= 0.05
if zoom_y <= 0.7:
stage += 1
elif stage == 2:
zoom_y += 0.05
if zoom_y >= 1:
stage += 1
elif stage == 3:
angle -= 1
if angle <= -90:
stage = 0
pygame.quit()
exit()