How to scale pyopengl texture size to pygame window size?

Question

Windows size : 640 * 480

Texture size : 1280 * 720

Hello, How can I scale the texture to the pygame window?

Answer 1

You've setup an orthographic projection:

glOrtho(0, self.windowWidth, self.windowHeight, 0, -1, 1)

If you want the texture to fill the whole window, then you have to draw a quad corresponding to the orthographic projection and the texture coordinates form (0, 0) to (1, 1):

glEnable(GL_TEXTURE_2D)

glBegin(GL_QUAD)

glTexCoord2f(0, 0)
glVertex2f(0, 0)

glTexCoord2f(1, 0)
glVertex2f(self.windowWidth, 0)

glTexCoord2f(1, 1)
glVertex2f(self.windowWidth, self.windowHeight)

glTexCoord2f(0, 1)
glVertex2f(0, self.windowHeight)

glEnd()

If you wan to keep the aspect ratio of the texture, then you have to scale the size of the quad. For instance:

left = 0
top = 0
width = self.windowWidth
height = self.windowHeight

sx = self.windowWidth / textureWidth 
sy = self.windowHeight / textureHeight 
if sx > sy:
    width *= sy / sx
    left = (self.windowWidth - width) / 2
else:
    height *= sx / sy  
    top = (self.windowHeight - height) / 2

glEnable(GL_TEXTURE_2D)

glBegin(GL_QUAD)
glTexCoord2f(0, 0)
glVertex2f(left, top)
glTexCoord2f(1, 0)
glVertex2f(left + width, top)
glTexCoord2f(1, 1)
glVertex2f(left + width, top + height)
glTexCoord2f(0, 1)
glVertex2f(left, top + height)
glEnd()