'''
Routines that render text on OpenGL without use of GLUT.
Code written by Christian Brugger & Stefan Hacker and
distributed under GNU General Public License.
'''
#!/usr/bin/env python
# -*- coding: utf-8
#
# Provides some text display functions for wx + ogl
# Copyright (C) 2007 Christian Brugger, Stefan Hacker
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
import wx
import struct as st
import OpenGL.GL as GL
import platform
"""
Optimize with psyco if possible, this gains us about 50% speed when
creating our textures in trade for about 4MBytes of additional memory usage for
psyco. If you don't like loosing the memory you have to turn the lines following
"enable psyco" into a comment while uncommenting the line after "Disable psyco".
"""
#Try to enable psyco
#try:
# import psyco
# psyco_optimized = False
#except ImportError:
# psyco = None
#Disable psyco
#
[docs]
class TextElement(object):
"""
A simple class for using system Fonts to display
text in an OpenGL scene
"""
def __init__(self,
text = '',
font = None,
foreground = wx.WHITE,
centered = False):
"""
text (String) - Text
font (wx.Font) - Font to draw with (None = System default)
foreground (wx.Colour)- Color of the text
or (wx.Bitmap)- Bitmap to overlay the text with
centered (bool) - Center the text
Initializes the TextElement
"""
# save given variables
self._text = text
self._lines = text.split('\n')
self._font = font
self._foreground = foreground
self._centered = centered
# init own variables
self._owner_cnt = 0 #refcounter
self._texture = None #OpenGL texture ID
self._text_size = None #x/y size tuple of the text
self._texture_size= None #x/y Texture size tuple
# create Texture
self.createTexture()
#---Internal helpers
def _getUpper2Base(self, value):
"""
Returns the lowest value with the power of
2 greater than 'value' (2^n>value)
"""
base2 = 1
while base2 < value:
base2 *= 2
return base2
#---Functions
[docs]
def draw_text(self, position = wx.RealPoint(0.,0.), scale = 1.0, rotation = 0):
"""
position (wx.RealPoint) - x/y Position to draw in scene
scale (float) - Scale
rotation (int) - Rotation in degree
Draws the text to the scene
"""
#Enable necessary functions
GL.glColor(1,1,1,1)
GL.glEnable(GL.GL_TEXTURE_2D)
GL.glEnable(GL.GL_ALPHA_TEST) #Enable alpha test
GL.glAlphaFunc(GL.GL_GREATER, 0)
GL.glEnable(GL.GL_BLEND) #Enable blending
GL.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA)
#Bind texture
GL.glBindTexture(GL.GL_TEXTURE_2D, self._texture)
ow, oh = self._text_size
w , h = self._texture_size
#Perform transformations
GL.glPushMatrix()
GL.glTranslatef(position.x, position.y, 0)
GL.glRotate(-rotation, 0, 0, 1)
GL.glScaled(scale, scale, scale)
if self._centered:
GL.glTranslate(-w/2, -oh/2, 0)
#Draw vertices
GL.glBegin(GL.GL_QUADS)
GL.glTexCoord2f(0,0); GL.glVertex2f(0,0)
GL.glTexCoord2f(0,1); GL.glVertex2f(0,h)
GL.glTexCoord2f(1,1); GL.glVertex2f(w,h)
GL.glTexCoord2f(1,0); GL.glVertex2f(w,0)
GL.glEnd()
GL.glPopMatrix()
#Disable features
GL.glDisable(GL.GL_BLEND)
GL.glDisable(GL.GL_ALPHA_TEST)
GL.glDisable(GL.GL_TEXTURE_2D)
[docs]
def createTexture(self):
"""
Creates a texture from the settings saved in TextElement, to be able to use normal
system fonts conviently a wx.MemoryDC is used to draw on a wx.Bitmap. As wxwidgets
device contexts don't support alpha at all it is necessary to apply a little hack
to preserve antialiasing without sticking to a fixed background color:
We draw the bmp in b/w mode so we can use its data as a alpha channel for a solid
color bitmap which after GL_ALPHA_TEST and GL_BLEND will show a nicely antialiased
text on any surface.
To access the raw pixel data the bmp gets converted to a wx.Image. Now we just have
to merge our foreground color with the alpha data we just created and push it all
into a OpenGL texture and we are DONE *inhalesdelpy*
DRAWBACK of the whole conversion thing is a really long time for creating the
texture. If you see any optimizations that could save time PLEASE CREATE A PATCH!!!
"""
# get a memory dc and assign a temporary bitmap
dc = wx.MemoryDC()
if 'phoenix' in wx.version():
dc.SelectObject(wx.Bitmap(100, 100))
else:
dc.SelectObject(wx.EmptyBitmap(100, 100))
# set our font
dc.SetFont(self._font)
# Approximate extend to next power of 2 and create our bitmap
# REMARK: You wouldn't believe how much fucking speed this little
# sucker gains compared to sizes not of the power of 2. It's like
# 500ms --> 0.5ms (on my ATI-GPU powered Notebook). On Sams nvidia
# machine there don't seem to occur any losses...bad drivers?
ow, oh = dc.GetMultiLineTextExtent(self._text)[:2]
w, h = self._getUpper2Base(ow), self._getUpper2Base(oh)
self._text_size = wx.Size(ow,oh)
self._texture_size = wx.Size(w,h)
if 'phoenix' in wx.version():
bmp = wx.Bitmap(wx.Size(w,h))
else:
bmp = wx.EmptyBitmap(w,h)
#Draw in b/w mode to bmp so we can use it as alpha channel
dc.SelectObject(bmp)
dc.SetBackground(wx.BLACK_BRUSH)
dc.Clear()
dc.SetTextForeground(wx.WHITE)
x,y = 0,0
centered = self.centered
for line in self._lines:
if not line: line = ' '
tw, th = dc.GetTextExtent(line)
if centered:
x = int(round((w-tw)//2))
dc.DrawText(line, x, y)
x = 0
y += th
#Release the dc
dc.SelectObject(wx.NullBitmap)
del dc
#Generate a correct RGBA data string from our bmp
"""
NOTE: You could also use wx.AlphaPixelData to access the pixel data
in 'bmp' directly, but the iterator given by it is much slower than
first converting to an image and using wx.Image.GetData().
"""
if 'phoenix' in wx.version():
img = wx.Bitmap.ConvertToImage(bmp)
alpha = img.GetData()
else:
img = wx.ImageFromBitmap(bmp)
alpha = img.GetData()
# if isinstance(self._foreground, wx.Colour):
"""
If we have a static color...
"""
r,g,b = self._foreground.Get()[:3]
if '2' in platform.python_version_tuple()[0]:
color = "%c%c%c" % (chr(r), chr(g), chr(b))
else:
color = st.pack('3B',r,g,b)
data = b''
for i in range(0, len(alpha)-1, 3):
if '2' in platform.python_version_tuple()[0]:
data += (color + str(alpha[i]))
else:
data += (color + st.pack('B',alpha[i]))
# elif isinstance(self._foreground, wx.Bitmap):
# """
# If we have a bitmap...
# """
# bg_img = wx.ImageFromBitmap(self._foreground)
# bg = bg_img.GetData()
# bg_width = self._foreground.GetWidth()
# bg_height = self._foreground.GetHeight()
#
# data = ''
#
# for y in range(0, h):
# for x in range(0, w):
# if (y > (bg_height-1)) or (x > (bg_width-1)):
# color = "%c%c%c" % (chr(0),chr(0),chr(0))
# else:
# pos = (x+y*bg_width) * 3
# color = bg[pos:pos+3]
# data += color + alpha[(x+y*w)*3]
# now convert it to ogl texture
self._texture = GL.glGenTextures(1)
GL.glBindTexture(GL.GL_TEXTURE_2D, self._texture)
GL.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR)
GL.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR)
GL.glPixelStorei(GL.GL_UNPACK_ROW_LENGTH, 0)
GL.glPixelStorei(GL.GL_UNPACK_ALIGNMENT, 2)
GL.glTexImage2D(GL.GL_TEXTURE_2D, 0, GL.GL_RGBA, w, h, 0, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, data)
[docs]
def deleteTexture(self):
"""
Deletes the OpenGL texture object
"""
if self._texture:
if GL.glIsTexture(self._texture):
GL.glDeleteTextures(self._texture)
else:
self._texture = None
[docs]
def bind(self):
"""
Increase refcount
"""
self._owner_cnt += 1
[docs]
def release(self):
"""
Decrease refcount
"""
self._owner_cnt -= 1
[docs]
def isBound(self):
"""
Return refcount
"""
return self._owner_cnt
def __del__(self):
"""
Destructor
"""
# self.deleteTexture()
del self._texture
#---Getters/Setters
def getText(self): return self._text
def getFont(self): return self._font
def getForeground(self): return self._foreground
def getCentered(self): return self._centered
def getTexture(self): return self._texture
def getTexture_size(self): return self._texture_size
def getOwner_cnt(self): return self._owner_cnt
def setOwner_cnt(self, value):
self._owner_cnt = value
#---Properties
text = property(getText, None, None, "Text of the object")
font = property(getFont, None, None, "Font of the object")
foreground = property(getForeground, None, None, "Color of the text")
centered = property(getCentered, None, None, "Is text centered")
owner_cnt = property(getOwner_cnt, setOwner_cnt, None, "Owner count")
texture = property(getTexture, None, None, "Used texture")
texture_size = property(getTexture_size, None, None, "Size of the used texture")
[docs]
class Text(object):
"""
A simple class for using System Fonts to display text in
an OpenGL scene. The Text adds a global Cache of already
created text elements to TextElement's base functionality
so you can save some memory and increase speed
"""
_texts = [] #Global cache for TextElements
def __init__(self,
text = 'Text',
font = None,
font_size = 8,
foreground = wx.WHITE,
centered = False):
"""
text (string) - displayed text
font (wx.Font) - if None, system default font will be used with font_size
font_size (int) - font size in points
foreground (wx.Colour) - Color of the text
or (wx.Bitmap) - Bitmap to overlay the text with
centered (bool) - should the text drawn centered towards position?
Initializes the text object
"""
#Init/save variables
self._aloc_text = None
self._text = text
self._font_size = font_size
self._foreground= foreground
self._centered = centered
#Check if we are offered a font
if not font:
#if not use the system default
self._font = wx.SystemSettings.GetFont(wx.SYS_DEFAULT_GUI_FONT)
else:
#save it
self._font = font
#Bind us to our texture
self._initText()
#---Internal helpers
def _initText(self):
"""
Initializes/Reinitializes the Text object by binding it
to a TextElement suitable for its current settings
"""
#Check if we already bound to a texture
if self._aloc_text:
#if so release it
self._aloc_text.release()
if not self._aloc_text.isBound():
self._texts.remove(self._aloc_text)
self._aloc_text = None
#Adjust our font
self._font.SetPointSize(self._font_size)
#Search for existing element in our global buffer
for element in self._texts:
if element.text == self._text and\
element.font == self._font and\
element.foreground == self._foreground and\
element.centered == self._centered:
# We already exist in global buffer ;-)
element.bind()
self._aloc_text = element
break
if not self._aloc_text:
# We are not in the global buffer, let's create ourselves
aloc_text = self._aloc_text = TextElement(self._text,
self._font,
self._foreground,
self._centered)
aloc_text.bind()
self._texts.append(aloc_text)
def __del__(self):
"""
Destructor
"""
aloc_text = self._aloc_text
aloc_text.release()
if not aloc_text.isBound():
self._texts.remove(aloc_text)
#---Functions
[docs]
def draw_text(self, position = wx.RealPoint(0.,0.), scale = 1.0, rotation = 0):
"""
position (wx.RealPoint) - x/y Position to draw in scene
scale (float) - Scale
rotation (int) - Rotation in degree
Draws the text to the scene
"""
self._aloc_text.draw_text(position, scale, rotation)
#---Setter/Getter
def getText(self): return self._text
[docs]
def setText(self, value, reinit = True):
"""
value (bool) - New Text
reinit (bool) - Create a new texture
Sets a new text
"""
self._text = value
if reinit:
self._initText()
def getFont(self): return self._font
[docs]
def setFont(self, value, reinit = True):
"""
value (bool) - New Font
reinit (bool) - Create a new texture
Sets a new font
"""
self._font = value
if reinit:
self._initText()
def getFont_size(self): return self._font_size
[docs]
def setFont_size(self, value, reinit = True):
"""
value (bool) - New font size
reinit (bool) - Create a new texture
Sets a new font size
"""
self._font_size = value
if reinit:
self._initText()
def getForeground(self): return self._foreground
[docs]
def setForeground(self, value, reinit = True):
"""
value (bool) - New centered value
reinit (bool) - Create a new texture
Sets a new value for 'centered'
"""
self._foreground = value
if reinit:
self._initText()
def getCentered(self): return self._centered
[docs]
def setCentered(self, value, reinit = True):
"""
value (bool) - New centered value
reinit (bool) - Create a new texture
Sets a new value for 'centered'
"""
self._centered = value
if reinit:
self._initText()
[docs]
def getTexture_size(self):
"""
Returns a texture size tuple
"""
return self._aloc_text.texture_size
[docs]
def getTextElement(self):
"""
Returns the text element bound to the Text class
"""
return self._aloc_text
[docs]
def getTexture(self):
"""
Returns the texture of the bound TextElement
"""
return self._aloc_text.texture
#---Properties
text = property(getText, setText, None, "Text of the object")
font = property(getFont, setFont, None, "Font of the object")
font_size = property(getFont_size, setFont_size, None, "Font size")
foreground = property(getForeground, setForeground, None, "Color/Overlay bitmap of the text")
centered = property(getCentered, setCentered, None, "Display the text centered")
texture_size = property(getTexture_size, None, None, "Size of the used texture")
texture = property(getTexture, None, None, "Texture of bound TextElement")
text_element = property(getTextElement,None , None, "TextElement bound to this class")
#Optimize critical functions
#if psyco and not psyco_optimized:
# psyco.bind(TextElement.createTexture)
# psyco_optimized = True