我正在创建一个有向图，但它最终比我的窗口大，所以我不想不断地制作一个更大的窗口，我想允许滚动。稍后我还将允许用户旋转图形，因为它将是 3D 的。
那么，如何在 pyglet 中滚动？
我找到了这个：
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(ClipBox.x1,ClipBox.x2,ClipBox.y1,ClipBox.y2,ClipBox.z1,ClipBox.z2);
glMatrixMode(GL_MODELVIEW);
但我不确定是否有更好的选择。
通过查看http://www.pyglet.org/doc/programming_guide/mouse_events.html我可以看到我需要使用哪些事件，例如鼠标拖动和滚轮，我只需要给用户一个印象视图正在按照他们的预期移动。
您可以转换模型矩阵或投影矩阵来做到这一点。
会有更好的方法，但据我所知，移动几何图形的最简单方法是在绘制之前使用 glTranslatef、glRotatef 和 glScalef。
在这个例子中，Camera 类只修改了 GL_PROJECTION 来设置视图模式，然后在绘制几何图形时修改 GL_MODELVIEW 矩阵来移动相机：
import pyglet
from pyglet.window import key
from pyglet.gl import *
def opengl_init():
""" Initial OpenGL configuration.
"""
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
glDepthFunc(GL_LEQUAL)
def playground():
""" Draw something here, like a white X.
"""
glColor4f(1, 1, 1, 1)
glBegin(GL_LINES)
glVertex3f(0, 0, 0)
glVertex3f(640, 480, 0)
glVertex3f(0, 480, 0)
glVertex3f(640, 0, 0)
glEnd()
class camera(object):
""" A camera.
"""
mode = 1
x, y, z = 0, 0, 512
rx, ry, rz = 30, -45, 0
w, h = 640, 480
far = 8192
fov = 60
def view(self, width, height):
""" Adjust window size.
"""
self.w, self.h = width, height
glViewport(0, 0, width, height)
print "Viewport " + str(width) + "x" + str(height)
if self.mode == 2:
self.isometric()
elif self.mode == 3:
self.perspective()
else:
self.default()
def default(self):
""" Default pyglet projection.
"""
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(0, self.w, 0, self.h, -1, 1)
glMatrixMode(GL_MODELVIEW)
def isometric(self):
""" Isometric projection.
"""
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(-self.w/2., self.w/2., -self.h/2., self.h/2., 0, self.far)
glMatrixMode(GL_MODELVIEW)
def perspective(self):
""" Perspective projection.
"""
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(self.fov, float(self.w)/self.h, 0.1, self.far)
glMatrixMode(GL_MODELVIEW)
def key(self, symbol, modifiers):
""" Key pressed event handler.
"""
if symbol == key.F1:
self.mode = 1
self.default()
print "Projection: Pyglet default"
elif symbol == key.F2:
print "Projection: 3D Isometric"
self.mode = 2
self.isometric()
elif symbol == key.F3:
print "Projection: 3D Perspective"
self.mode = 3
self.perspective()
elif self.mode == 3 and symbol == key.NUM_SUBTRACT:
self.fov -= 1
self.perspective()
elif self.mode == 3 and symbol == key.NUM_ADD:
self.fov += 1
self.perspective()
else: print "KEY " + key.symbol_string(symbol)
def drag(self, x, y, dx, dy, button, modifiers):
""" Mouse drag event handler.
"""
if button == 1:
self.x -= dx*2
self.y -= dy*2
elif button == 2:
self.x -= dx*2
self.z -= dy*2
elif button == 4:
self.ry += dx/4.
self.rx -= dy/4.
def apply(self):
""" Apply camera transformation.
"""
glLoadIdentity()
if self.mode == 1: return
glTranslatef(-self.x, -self.y, -self.z)
glRotatef(self.rx, 1, 0, 0)
glRotatef(self.ry, 0, 1, 0)
glRotatef(self.rz, 0, 0, 1)
def x_array(list):
""" Converts a list to GLFloat list.
"""
return (GLfloat * len(list))(*list)
def axis(d=200):
""" Define vertices and colors for 3 planes
"""
vertices , colors = [], []
#XZ RED
vertices.extend([-d, 0, -d, d, 0, -d, d, 0, d, -d, 0, d])
for i in range (0, 4):
colors.extend([1, 0, 0, 0.5])
#YZ GREEN
vertices.extend([0, -d, -d, 0, -d, d, 0, d, d, 0, d, -d])
for i in range (0, 4):
colors.extend([0, 1, 0, 0.5])
#XY BLUE
vertices.extend([-d, -d, 0, d, -d, 0, d, d, 0, -d, d, 0])
for i in range (0, 4):
colors.extend([0, 0, 1, 0.5])
return x_array(vertices), x_array(colors)
AXIS_VERTICES, AXIS_COLORS = axis()
def draw_vertex_array(vertices, colors, mode=GL_LINES):
""" Draw a vertex array.
"""
glEnableClientState(GL_VERTEX_ARRAY)
glEnableClientState(GL_COLOR_ARRAY)
glColorPointer(4, GL_FLOAT, 0, colors)
glVertexPointer(3, GL_FLOAT, 0, vertices)
glDrawArrays(GL_QUADS, 0, len(vertices)/3)
glDisableClientState(GL_VERTEX_ARRAY)
glDisableClientState(GL_COLOR_ARRAY)
def draw_axis():
""" Draw the 3 planes
"""
glEnable(GL_DEPTH_TEST)
draw_vertex_array(AXIS_VERTICES, AXIS_COLORS, GL_QUADS)
glDisable(GL_DEPTH_TEST)
class CameraWindow(pyglet.window.Window):
def __init__(self):
super(CameraWindow, self).__init__(resizable=True)
opengl_init()
self.cam = camera()
self.on_resize = self.cam.view
self.on_key_press = self.cam.key
self.on_mouse_drag = self.cam.drag
def on_draw(self):
self.clear()
self.cam.apply()
draw_axis()
playground()
if __name__ == '__main__':
print "OpenGL Projections"
print "---------------------------------"
print "Projection matrix -> F1, F2, F3"
print "Camera -> Drag LMB, CMB, RMB"
print ""
window = CameraWindow()
pyglet.app.run()