时间戳

首页 > 解决方案 > 使用 Kivy 实现 VRAM

kivy - 使用 Kivy 实现 VRAM

问题描述

我是 Kiwy 的新手。我的任务是实现处理器显存。假设我们有一个包含 10 个布尔元素的数组。

如果位置为 i 的元素为 True，则坐标为 [i, 0] 的像素为绿色，否则为红色。如何用 kivy 实现这一点，以便当数组元素发生变化时，像素颜色会立即发生变化？

标签： kivykivy-language

解决方案

您可以使用FrameBuffer. 在下面的代码中，我没有实现布尔数组，但这很简单。该代码显示了如何处理显示部分：

from kivy.app import App
from kivy.graphics import Fbo, Rectangle
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.widget import Widget
from array import array

class FboTest(Widget):
    def __init__(self, **kwargs):
        super(FboTest, self).__init__(**kwargs)
        self.fbo_size = 256

        # first step is to create the fbo and use the fbo texture on a Rectangle
        with self.canvas:
            # create the fbo
            self.fbo = Fbo(size=(self.fbo_size, self.fbo_size))

            # show our fbo on the widget in a Rectangle
            Rectangle(size=(self.fbo_size, self.fbo_size), texture=self.fbo.texture)

        size = self.fbo_size * self.fbo_size
        buf = [255, 0, 0] * size  # initialize buffer to all red pixels
        # initialize the array with the buffer values
        self.arr = array('B', buf)
        # now blit the array
        self.fbo.texture.blit_buffer(self.arr, colorfmt='rgb', bufferfmt='ubyte')


class FboPlayApp(App):

    def build(self):
        root = FloatLayout(size_hint=(None, None), size=(750, 750))
        self.fbotest = FboTest(size_hint=(None, None), size=(512, 512))
        button = Button(text='click', size_hint=(None, None), size=(75, 25), pos=(500, 500), on_release=self.do_button)
        root.add_widget(self.fbotest)
        root.add_widget(button)
        return root

    def do_button(self, *args):
        # set some pixels to green
        for x in range(64, 84):
            for y in range(25, 45):
                self.set_pixel(x, y, True)
        # blit the updated pixels to the FBO
        self.fbotest.fbo.texture.blit_buffer(self.fbotest.arr, colorfmt='rgb', bufferfmt='ubyte')

    def set_pixel(self, x, y, isGreen):
        # set pixel at (x,y) to green if isGreen is True, otherwise turn them red
        index = y * self.fbotest.fbo_size * 3 + x * 3
        if isGreen:
            self.fbotest.arr[index] = 0
            self.fbotest.arr[index+1] = 255
            self.fbotest.arr[index+2] = 0
        else:
            self.fbotest.arr[index] = 255
            self.fbotest.arr[index+1] = 0
            self.fbotest.arr[index+2] = 0

if __name__ == "__main__":
    FboPlayApp().run()

运行此应用程序并单击按钮将某些像素的颜色从红色更改为绿色。

推荐阅读