Question

我使用OpenGl测试了应用程序，并且一直是Mesh parametr fmt的问题，它用于映射列表顶点。在找到问题的解决方案时，我使用了更简单的例子。对于我在这里的问题，我编辑了Kivy手册中的原始代码。要在codeall和mz修改的代码变体之间添加代码。

我使用以下结果测试了参数fmt的下一个变体：

vertex_format = [('v_pos', 3, 'float')] - ＆gt;
例外：expected byte, found str
vertex_format = [(b'v_pos', 3, 'float')] - ＆gt;
没有屏幕上的场景图片
我不使用参数fmt - ＆gt;
场景图片的几何图形不正确

您能解释我使用parametr fmt吗？感谢您的关注！

from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.boxlayout import BoxLayout
from kivy.app import App
from kivy.graphics import Mesh
from functools import partial
from math import cos, sin, pi


class MeshTestApp(App):

    def change_mode(self, mode, *largs):
        self.mesh.mode = mode

    def build_mesh(self):
        #switch between original and alteration code
#        switch = False   #original
        switch = True   #alteration

        """ returns a Mesh of a rough circle. """
        vertices = []
        indices = []
        step = 10
        istep = (pi * 2) / float(step) 

        # my alteration
        # mask for mapping list of vertices
        # where is problem with format? 
        vertex_format = [(b'v_pos', 2,"float")] 

        for i in range(step):
            x = 300 + cos(istep * i) * 100
            y = 300 + sin(istep * i) * 100

            if switch == False:
                # originall code
                vertices.extend([x, y, 0, 0])
            else:
                # my alteration
                vertices.extend([x, y])

            indices.append(i)

        if switch == False:
            # originall code
            return Mesh(vertices=vertices, indices=indices)
        else:
            # my alteration
            return Mesh(vertices=vertices, indices=indices, fmt = vertex_format )

    def build(self):
        wid = Widget()
        with wid.canvas:
            self.mesh = self.build_mesh()

        layout = BoxLayout(size_hint=(1, None), height=50)
        for mode in ('points', 'line_strip', 'line_loop', 'lines',
                'triangle_strip', 'triangle_fan'):
            button = Button(text=mode)
            button.bind(on_release=partial(self.change_mode, mode))
            layout.add_widget(button)

        root = BoxLayout(orientation='vertical')
        root.add_widget(wid)
        root.add_widget(layout)

        return root


if __name__ == '__main__':
    MeshTestApp().run()

KIvy：映射使用类Mash的顶点列表

0 个答案: