CODEWITHSUNDEEP
pythonimagetextdrawpyglet
lilcutthroat
lilcutthroat

Reputation: 93

Pyglet text background is not transparent

I am using Pyglet to create a main menu for my python game. I want to draw text on top of a box that would act as its container. Whenever I render the text, instead of it having a transparent background, it draws whatever the glClearColor is set to. This also happens whenever I try and draw an image that has no background.

I am currently using these two lines for my textbox and the text.

self.text_box = pyglet.sprite.Sprite(pyglet.image.load('../Resources/Textures/Menu/text_box.png'),640-150,360-25, batch=self.menuBatch,group=boxGroup)

self.play_text = pyglet.text.Label("Play", font_name="Arial", font_size=32, x=640, y=360, anchor_x='center', anchor_y='center', color=(255,255,255,255), batch=self.menuBatch,group=textGroup)

Then I just call self.menuBatch.draw(). A picture of the problem I am having is:

enter image description here

Upvotes: 3

Views: 1632

Answers (2)

Rick Bowen
Rick Bowen

Reputation: 65

I have done something very similar to this before when making the GUI for one of my 3D programs. To make things very simple, I firstly turned off GL_DEPTH_TEST before the draw() call and then I re-enabled GL_DEPTH_TEST after the draw() call. I believe that the reason why the previous answer was working for them is because they didn't have GL_DEPTH_TEST enabled in the first place. I made a button class that you could maybe use as well (It's important to note that the argument "pos" is for the (x, y) coordinate of the lower left corner of the button and the argument "dim" is for the (width, height) dimensions of the button. The "texture_coords" argument refers to the texture coordinates of the background image of the button. If you want the full image, just leave it at the default. The rest is pretty self explanatory). So here's the code:

class Button:
    def __init__(self, btn_img_file, text = "Button", pos = (0, 0), dim = (10, 10), text_color = (255, 255, 255), texture_coords = (0, 0, 1, 0, 1, 1, 0, 1)):
        self.x, self.y = pos
        self.w, self.h = dim
        self.text = text
        self.img = btn_img_file
        self.tex = get_tex(self.img)
        self.coords = texture_coords
        self.color = text_color
        self.batch = pyglet.graphics.Batch()

    def on_click(self, mouse_x, mouse_y, function, *args, **kwargs):
        x, y = self.x, self.y
        X, Y = x + self.w, y + self.h
        if mouse_x > x and mouse_x < X and mouse_y > y and mouse_y < Y:
            function(*args, **kwargs)

    def draw(self):
        x, y = self.x, self.y
        X, Y = x + self.w, y + self.h
        font_size = (self.w // len(self.text)) - 5
        label = pyglet.text.Label(self.text,
            font_name = 'Times New Roman',
            font_size = font_size,
            x = x + (self.w // 2), y = y + (self.h // 2),
            anchor_x = 'center', anchor_y = 'center',
            color = (*self.color, 255))
        self.batch.add(4, GL_QUADS, self.tex, ('v2f', (x, y, X, y, X, Y, x, Y)), ('t2f', self.coords))
        glDisable(GL_DEPTH_TEST)
        self.batch.draw()
        label.draw()
        glEnable(GL_DEPTH_TEST)

I hope this was helpful!

~ Rick Bowen

Upvotes: 1

msarch
msarch

Reputation: 345

For transparency effects to work, 'blend' should be enabled in OpenGL.

To enable blend:

glEnable(GL_BLEND)                                  # transparency
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)   # transparency

This complete snippet is working for me:

import pyglet
from pyglet.gl import *


# Pyglet Window stuff ---------------------------------------------------------
batch = pyglet.graphics.Batch()  # holds all graphics
config = Config(sample_buffers=1, samples=4,depth_size=16, double_buffer=True, mouse_visible=False)
window = pyglet.window.Window(fullscreen=False, config=config)

glClearColor(  0, 100,   0, 255)  # background color
glEnable(GL_LINE_SMOOTH)
glHint(GL_LINE_SMOOTH_HINT, GL_DONT_CARE)
glEnable(GL_BLEND)                                  # transparency
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)   # transparency

play_text = pyglet.text.Label("Play", font_name="Arial", font_size=32, x=240, y=140, anchor_x='center', anchor_y='center', color=(255,0,255,255), batch=batch,group=None)
text_box = pyglet.sprite.Sprite(pyglet.image.load('text_box.png'),240-150,160-25, batch=batch,group=None)

@window.event
def draw(dt):
    window.clear()
    batch.draw()


if __name__ == "__main__":
    pyglet.clock.schedule_interval(draw, 1.0/60)
    pyglet.app.run()

screen

Upvotes: 2

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