An OpenGL example in Python using PyOpenGL and PyGame modules to render a spinning triangle while the FPS (Frames Per Second) is displayed in the upper right hand corner using a TrueType font.
Python, 146 lines
Download
Copy to clipboard1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 | """
font.py -- Displays FPS in OpenGL using TrueType fonts.
Copyright (c) 2002. Nelson Rush. All rights reserved.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
"""
from OpenGL.GL import *
from OpenGL.GLU import *
from pygame.locals import *
from pygame.display import *
from pygame.event import *
from pygame.key import *
from pygame.mouse import *
from pygame.font import *
from pygame.image import *
from pygame.time import *
from pygame import *
import sys
class Engine:
def __init__(self,w,h):
init()
display.init()
display.set_mode([w,h], DOUBLEBUF|OPENGL|HWPALETTE|HWSURFACE)
self.initgl()
self.resize(w,h)
mouse.set_visible(0)
self.w = w
self.h = h
font.init()
if not font.get_init():
print 'Could not render font.'
sys.exit(0)
self.font = font.Font('font.ttf',18)
self.char = []
for c in range(256):
self.char.append(self.CreateCharacter(chr(c)))
self.char = tuple(self.char)
self.lw = self.char[ord('0')][1]
self.lh = self.char[ord('0')][2]
self.angle = 0.0
self.frames = self.t = self.t_start = self.fps = 0
def initgl(self):
glClearColor(0.0, 0.0, 0.0, 0.0)
glClearDepth(1.0)
glEnable(GL_DEPTH_TEST)
glDepthFunc(GL_LEQUAL)
glShadeModel(GL_SMOOTH)
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
def resize(self,w,h):
if h == 0: h = 1
glViewport(0, 0, w, h)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
gluPerspective(45.0, float(w) / float(h), 0.5, 150.0)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
def CreateCharacter(self, s):
try:
letter_render = self.font.render(s, 1, (255,255,255), (0,0,0))
letter = image.tostring(letter_render, 'RGBA', 1)
letter_w, letter_h = letter_render.get_size()
except:
letter = None
letter_w = 0
letter_h = 0
return (letter, letter_w, letter_h)
def textView(self):
glViewport(0,0,self.w,self.h)
glMatrixMode(GL_PROJECTION)
glLoadIdentity()
glOrtho(0.0, self.w - 1.0, 0.0, self.h - 1.0, -1.0, 1.0)
glMatrixMode(GL_MODELVIEW)
glLoadIdentity()
def Print(self,s,x,y):
s = str(s)
i = 0
lx = 0
length = len(s)
self.textView()
glPushMatrix()
while i < length:
glRasterPos2i(x + lx, y)
ch = self.char[ ord( s[i] ) ]
glDrawPixels(ch[1], ch[2], GL_RGBA, GL_UNSIGNED_BYTE, ch[0])
lx += ch[1]
i += 1
glPopMatrix()
def DrawFPS(self, x, y):
self.t = time.get_ticks()
self.frames += 1
if self.t - self.t_start > 1000:
self.fps = self.frames * 1000 / (self.t - self.t_start)
self.t_start = self.t
self.frames = 0
self.Print(self.fps, x, y)
def draw(self):
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glLoadIdentity()
self.resize(self.w,self.h)
glTranslatef(0.0, 0.0, -6.0)
glPushMatrix()
glRotatef(self.angle, 0.0, 1.0, 0.0)
glBegin(GL_TRIANGLES)
glColor3f(0.0, 0.0, 1.0)
glVertex3f(0.0, 1.0, 0.0)
glVertex3f(-1.0, -1.0, 0.0)
glVertex3f(1.0, -1.0, 0.0)
glEnd()
glPopMatrix()
self.DrawFPS(self.w - (self.lw * 3), self.h - self.lh)
self.angle += 1.0
def run(self):
while 1:
e = event.poll()
k = key.get_pressed()
if e.type == KEYDOWN and e.key == K_ESCAPE: break
self.draw()
display.flip()
if __name__ == '__main__':
engine = Engine(640,480)
engine.run()
font.quit()
display.quit()
|
It buffers the TTF into memory and draws to any position specified in the framebuffer. Useful for displaying stats, general info., FPS, and text in a drop down console.
Disadvantage: Color/style cannot be changed on the fly without re-rendering entire character chart. And I haven't figured out just yet how to make the background transparent.
how to make the background transparent. I didn't read the above example very carefully, but I do know how to draw a transparent-background pygame surface with opengl. Here's the relevant code from my program: