3

我正在尝试编写一些代码，将单个图像显示为wxGLCanvas容器内的简单 2D 纹理矩形。

这是到目前为止我所拥有的一个可运行的示例：

import wx
from wxPython.glcanvas import wxGLCanvas
from OpenGL.GLU import *
from OpenGL.GL import *
import numpy as np
from scipy.misc import ascent


def run():
    imarray = np.float32(ascent())
    imarray = np.repeat(imarray[..., np.newaxis], 3, axis=2)
    app = wx.PySimpleApp()
    frame = wx.Frame(None, title='Simple 2D texture')
    canvas = myGLCanvas(frame, imarray)
    frame.Show(True)
    app.MainLoop()


class myGLCanvas(wxGLCanvas):

    def __init__(self, parent, image):
        attribList = [wx.glcanvas.WX_GL_DOUBLEBUFFER]
        wxGLCanvas.__init__(self, parent, -1, attribList=attribList)
        wx.EVT_PAINT(self, self.OnPaint)
        self.image = np.float32(image)
        self.InitProjection()
        self.InitTexture()
        pass

    def OnPaint(self, event):
        """Called whenever the window gets resized, uncovered etc."""
        self.SetCurrent()
        dc = wx.PaintDC(self)
        self.OnDraw()
        self.SwapBuffers()
        pass

    def InitProjection(self):
        """Enable the depth buffer and initialize the viewport and
        projection matrix"""
        glEnable(GL_DEPTH_TEST)
        glDepthFunc(GL_LEQUAL)
        width = self.image.shape[1]
        height = self.image.shape[0]
        glViewport(0, 0, width, height)
        glMatrixMode(GL_PROJECTION)
        glLoadIdentity()
        glOrtho(0, width, height, 0, -1, 1)
        pass

    def InitTexture(self):
        """Initializes the texture from a numpy array"""
        self.texture = glGenTextures(1)
        glEnable(GL_TEXTURE_2D)
        glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
        glBindTexture(GL_TEXTURE_2D, self.texture)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP)
        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP)
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE)
        glTexImage2D(GL_TEXTURE_2D, 0,
                     GL_RGB,
                     self.image.shape[1], self.image.shape[0], 0,
                     GL_RGB,
                     GL_FLOAT,
                     self.image)
        glDisable(GL_TEXTURE_2D)
        pass

    def OnDraw(self):
        """Draw a textured rectangle slightly smaller than the viewport"""
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
        glClearColor(0., 0., 0., 0.)
        glClearDepth(1)
        glMatrixMode(GL_MODELVIEW)
        glLoadIdentity()
        glBindTexture(GL_TEXTURE_2D, self.texture)
        glEnable(GL_TEXTURE_2D)
        # draw a textured quad, shrink it a bit so the edge is clear
        glBegin(GL_QUADS)
        glTexCoord2f(0., 0.)
        glVertex3f(-0.9, -0.9, 0.)
        glTexCoord2f(1., 0.)
        glVertex3f(0.9, -0.9, 0.)
        glTexCoord2f(1., 1.)
        glVertex3f(0.9, 0.9, 0.)
        glTexCoord2f(0., 1.)
        glVertex3f(-0.9, 0.9, 0.)
        glEnd()
        glDisable(GL_TEXTURE_2D)
        pass

if __name__ == '__main__':
    run()

这成功地绘制了一个矩形，但无法对其进行纹理化 - 我看到的只是一个白色矩形。知道我做错了什么吗？

4

1 回答 1

8

好吧，我犯的一个严重错误是没有将输入数据的浮点值缩放到 0 到 1 之间——我所有的像素都 > 1，所以四边形呈现为白色！我在找到如何使用wxGLCanvases 的好例子时遇到了一些麻烦，所以这里有一个简单的纹理渲染在 awxGLCanvas中，供任何可能觉得它有用的人使用。

import numpy as np
from scipy.misc import ascent
import OpenGL.GL as gl
import wx
from wx.glcanvas import GLCanvas


class Canvas(GLCanvas):

    def __init__(self, parent):
        """create the canvas """
        super(Canvas, self).__init__(parent)
        self.texture = None

        # execute self.onPaint whenever the parent frame is repainted
        wx.EVT_PAINT(self, self.onPaint)

    def initTexture(self):
        """init the texture - this has to happen after an OpenGL context
        has been created
        """

        # make the OpenGL context associated with this canvas the current one
        self.SetCurrent()

        data = np.uint8(np.flipud(ascent()))
        w, h = data.shape

        # generate a texture id, make it current
        self.texture = gl.glGenTextures(1)
        gl.glBindTexture(gl.GL_TEXTURE_2D, self.texture)

        # texture mode and parameters controlling wrapping and scaling
        gl.glTexEnvf(gl.GL_TEXTURE_ENV, gl.GL_TEXTURE_ENV_MODE, gl.GL_MODULATE)
        gl.glTexParameterf(
            gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_S, gl.GL_REPEAT)
        gl.glTexParameterf(
            gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_T, gl.GL_REPEAT)
        gl.glTexParameterf(
            gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER, gl.GL_LINEAR)
        gl.glTexParameterf(
            gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER, gl.GL_LINEAR)

        # map the image data to the texture. note that if the input
        # type is GL_FLOAT, the values must be in the range [0..1]
        gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_RGB, w, h, 0,
                        gl.GL_LUMINANCE, gl.GL_UNSIGNED_BYTE, data)

    def onPaint(self, event):
        """called when window is repainted """
        # make sure we have a texture to draw
        if not self.texture:
            self.initTexture()
        self.onDraw()

    def onDraw(self):
        """draw function """

        # make the OpenGL context associated with this canvas the current one
        self.SetCurrent()

        # set the viewport and projection
        w, h = self.GetSize()
        gl.glViewport(0, 0, w, h)

        gl.glMatrixMode(gl.GL_PROJECTION)
        gl.glLoadIdentity()
        gl.glOrtho(0, 1, 0, 1, 0, 1)

        gl.glMatrixMode(gl.GL_MODELVIEW)
        gl.glLoadIdentity()
        gl.glClear(gl.GL_COLOR_BUFFER_BIT)

        # enable textures, bind to our texture
        gl.glEnable(gl.GL_TEXTURE_2D)
        gl.glBindTexture(gl.GL_TEXTURE_2D, self.texture)
        gl.glColor3f(1, 1, 1)

        # draw a quad
        gl.glBegin(gl.GL_QUADS)
        gl.glTexCoord2f(0, 1)
        gl.glVertex2f(0, 1)
        gl.glTexCoord2f(0, 0)
        gl.glVertex2f(0, 0)
        gl.glTexCoord2f(1, 0)
        gl.glVertex2f(1, 0)
        gl.glTexCoord2f(1, 1)
        gl.glVertex2f(1, 1)
        gl.glEnd()

        gl.glDisable(gl.GL_TEXTURE_2D)

        # swap the front and back buffers so that the texture is visible
        self.SwapBuffers()


def run():
    app = wx.App()
    fr = wx.Frame(None, size=(512, 512), title='wxPython texture demo')
    canv = Canvas(fr)
    fr.Show()
    app.MainLoop()

if __name__ == "__main__":
    run()
于 2013-02-20T04:33:13.633 回答