Engendro 3D™ on Github

Finally, Engendro 3D, the Python based OpenGL game engine arrives to Github. If you want to try the engine so far, to criticize, help or  whatever, visit


to clone or fork and try it.

While the published version is still a very early and incomplete alpha, I needed to upload the work I have been doing on this engine and the supporting projects, at least as a backup… and I’m very happy for  doing it, since just yesterday my disk failed, taking with it a lot of work. But now I have an almost updated copy!

I’m not a friend of backups, and this have slowed down the progress on many little things I have started (and never finished) in the past, including the engine, when I sufer a failure, but now I can just clone from the repos 😀


Python SDL2 TTF test

For cross platform windowing, input, font rendering and probably the entire 2d gui render of the engine, I have decided to use PySDL2, since I had some troubles with SFML (crashes in debug mode in PyCharm).

Next is an almost direct conversion from C to Python of the example found here:


The Glametrix font I used comes from here:


I placed the SDL2 and SDL2_ttf libraries in the script’s folder, inside another folder called ‘libs’ and the font in a folder called ‘font’.




import os
from sys import exit
from ctypes import c_long, pointer

sdlpath = os.path.join(os.path.dirname(__file__), 'libs')
os.environ['PYSDL2_DLL_PATH'] = sdlpath

from sdl2 import *
from sdl2.sdlttf import *

def renderTexture(tex, ren, x, y):
    :type ren: SDL_Renderer
    :type tex: SDL_Texture

    #Setup the destination rectangle to be at the position we want
    dst = SDL_Rect(x, y)
    w = pointer(c_long(0))
    h = pointer(c_long(0))
    #Query the texture to get its width and height to use
    SDL_QueryTexture(tex, None, None, w, h)
    dst.w = w.contents.value
    dst.h = h.contents.value
    SDL_RenderCopy(ren, tex, None, dst)

def renderText(message, fontFile, color, fontSize, renderer):

    :rtype : SDL_Texture
    # Open the font
    font = TTF_OpenFont(fontFile, fontSize)
    p = SDL_GetError()
    if font is None or not p == '':
        print("TTF_OpenFont error: " + p)
        return None

    #We need to first render to a surface as that's what TTF_RenderText
    #returns, then load that surface into a texture
    surf = TTF_RenderText_Blended(font, message, color)

    if surf is None:
        return None

    texture = SDL_CreateTextureFromSurface(renderer, surf)
    if texture is None:

    #Clean up the surface and font
    return texture

#Create an application window with the following settings:
window = SDL_CreateWindow(
    "SDL2 TTF test",  # window title
    SDL_WINDOWPOS_CENTERED,  # initial x position
    SDL_WINDOWPOS_CENTERED,  # initial y position
    640,  # width, in pixels
    480,  # height, in pixels

renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED)

tfi = TTF_Init()
if tfi != 0:

#We'll render the string "TTF fonts are cool!" in white
#Color is in RGB format
color = SDL_Color(255, 255, 255)
fontpath = os.path.join(os.path.dirname(__file__), 'font', 'Glametrix.otf')
image = renderText("TTF fonts are cool!", fontpath,
                   color, 64, renderer)

if image is None:

#Getting the window size.
SCREEN_WIDTH = pointer(c_long(0))
SCREEN_HEIGHT = pointer(c_long(0))

#Get the texture w/h so we can center it in the screen
iW = pointer(c_long(0))
iH = pointer(c_long(0))
SDL_QueryTexture(image, None, None, iW, iH)
x = SCREEN_WIDTH.contents.value / 2 - iW.contents.value / 2
y = SCREEN_HEIGHT.contents.value / 2 - iH.contents.value / 2

r = 1
event = SDL_Event()
while r:
    if SDL_PollEvent(event):
        if event.type == SDL_QUIT:
            r = 0
        elif event.type == SDL_WINDOWEVENT:
            if event.window.event == SDL_WINDOWEVENT_RESIZED:
                SDL_GetWindowSize(window, SCREEN_WIDTH, SCREEN_HEIGHT)
                x = SCREEN_WIDTH.contents.value / 2 - iW.contents.value / 2
                y = SCREEN_HEIGHT.contents.value / 2 - iH.contents.value / 2
        if r:
            #We can draw our message as we do any other texture, since it's been
            #rendered to a texture
            renderTexture(image, renderer, x, y)


I moved the drawing stuff to the event processing so the text is drawn only if there is a change (window re-paint, resize).

PS: Somebody knows a way to avoid using ctypes pointers in the few PySDL2 functions that need them?