如何在 Python 的 OpenGL 3.2 GtkGLArea 中渲染由 OpenCV 捕获的图像？许多在线示例已有 10 年历史，已过时，并且使用的是 OpenGL 2.1 或 1.1 示例。
我能做到这一点的唯一方法是通过着色器。在 GtkGLArea 中绘制任何东西的唯一工作示例是这个：
在 Python GTK3 中使用 Gtk GLArea
我在 C++ 中找到了这个示例并将其翻译成 Python，但我无法让它工作或输出任何东西。
如何使用 OpenGL 显示图像
这是我的代码，它不显示任何内容。我做错了什么？
编写OpenCV捕获线程调用的显示函数：
import os
import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, GdkPixbuf, GLib
USE_OPENGL = True
def writeDisplay(uiBuilder, frame, imageDisplay):
# Write Frame
frame = cv.cvtColor(frame, cv.COLOR_BGR2RGB)
if USE_OPENGL:
# Render frame using OpenGL
GLib.idle_add(imageDisplay.render, frame)
OpenGL 渲染器 GTK 小部件
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from OpenGL.GL import *
from OpenGL.GL import shaders
import numpy as np
VERTEX_SOURCE = '''
#version 330
layout (location=0) in vec3 position;
layout (location=1) in vec3 color;
layout (location=2) in vec2 texCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
{
gl_Position = vec4(position,1.0);
ourColor = color;
TexCoord= vec2(texCoord.x,1.0-texCoord.y);
}'''
FRAGMENT_SOURCE ='''
#version 330
in vec3 ourColor;
in vec2 TexCoord;
out vec4 color;
uniform sampler2D ourTexture;
void main(){
color = texture(ourTexture , TexCoord);
};'''
recVertices = np.array([
# Positions Colors Texture Coords
0.5, 0.5, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, # Top Right
0.5, -0.5, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, # Bottom Right
-0.5, -0.5, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, # Bottom Left
-0.5, 0.5, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0 # Top Left
], dtype=np.float32)
indices = np.array([
0, 1, 3, # First Triangle
1, 2, 3 # Second Triangle
])
def checkGlError(op: str):
error = glGetError()
if error is not None and error != 0:
print("after %s() glError (0x%x)", op, error)
# Based on examples:
# https://stackoverflow.com/questions/42153819/how-to-load-and-display-an-image-in-opengl-es-3-0-using-c
# https://stackoverflow.com/questions/47565884/use-of-the-gtk-glarea-in-pygobject-gtk3
class OpenGLRenderer(Gtk.GLArea):
def __init__(self):
Gtk.GLArea.__init__(self)
self.connect("realize", self.onRealize)
self.connect("render", self.onRender)
self.ctx = None
self.frame = None
self.area = None
self.shaderProgram = None
self.positionHandle = None
self.textureId = None
self.vao = None
def onRealize(self, area):
error = area.get_error()
if error != None:
print("your graphics card is probably too old : ", error)
else:
print(area, "realize... fine so far")
self.ctx = self.get_context()
self.ctx.make_current()
print("OpenGL realized", self.ctx)
def onRender(self, area, ctx):
self.render(self.frame)
return True
def setupGraphics(self, width, height):
if self.shaderProgram is None:
# Load Shaders, Create program, Setup Graphics
vertexShader = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(vertexShader, VERTEX_SOURCE)
glCompileShader(vertexShader)
pixelShader = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(pixelShader, FRAGMENT_SOURCE)
glCompileShader(pixelShader)
self.shaderProgram = glCreateProgram()
glAttachShader(self.shaderProgram, vertexShader)
glAttachShader(self.shaderProgram, pixelShader)
glLinkProgram(self.shaderProgram)
self.positionHandle = glGetAttribLocation(self.shaderProgram, "position")
glViewport(0, 0, width, height)
def initBuffers(self):
# Initialize an buffer to store all the verticles and transfer them to the GPU
self.vao = glGenVertexArrays(1) # Generate VAO
vbos = glGenBuffers(1) # Generate VBO
ebo = glGenBuffers(1) # Generate EPBO
glBindVertexArray(self.vao) # Bind the Vertex Array
glBindBuffer(GL_ARRAY_BUFFER, vbos) # Bind verticles array for OpenGL to use
glBufferData(GL_ARRAY_BUFFER, len(recVertices), recVertices, GL_STATIC_DRAW)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo) # Bind the indices for information about drawing sequence
glBufferData(GL_ELEMENT_ARRAY_BUFFER, len(indices), indices, GL_STATIC_DRAW)
# 1. set the vertex attributes pointers
# Position Attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(0))
glEnableVertexAttribArray(0)
# Color Attribute
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(3 * sizeof(GLfloat)))
glEnableVertexAttribArray(1)
# Texture Coordinate Attribute
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(6 * sizeof(GLfloat)))
glEnableVertexAttribArray(2)
glBindVertexArray(0) # 3. Unbind VAO
def generateTexture(self, frame):
# Update Frame
self.frame = frame
# If we have a frame to display
if frame is not None:
# extract array from Image
h, w, d = frame.shape
# Generate Texture
self.textureId = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, self.textureId) # Bind our 2D texture so that following set up will be applied
# Set texture wrapping parameter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_MIRRORED_REPEAT)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_MIRRORED_REPEAT)
# Set texture Filtering parameter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, frame)
glGenerateMipmap(GL_TEXTURE_2D)
glBindTexture(GL_TEXTURE_2D, 0) # Unbind 2D textures
def render(self, frame):
# Set OpenGL Render Context
if self.ctx is not None and frame is not None:
self.ctx.make_current()
# extract array from Image
h, w, d = frame.shape
# Initialize Graphics
self.setupGraphics(w, h)
# Generate Texture
self.generateTexture(frame)
# Clear Screen
glClearColor(0, 0, 1, 1)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
# Render Frame
glUseProgram(self.shaderProgram)
# checkGlError("glUseProgram")
# glVertexAttribPointer(self.positionHandle, 2, GL_FLOAT, GL_FALSE, 0, recVertices)
# checkGlError("glVertexAttribPointer")
# glEnableVertexAttribArray(self.positionHandle)
# checkGlError("glEnableVertexAttribArray")
# glDrawArrays(GL_TRIANGLE_FAN, 0, 4)
# checkGlError("glDrawArrays")
glActiveTexture(GL_TEXTURE0)
checkGlError("glActiveTexture")
glBindTexture(GL_TEXTURE_2D, self.textureId)
checkGlError("glBindTexture")
mlocation = glGetUniformLocation(self.shaderProgram, "ourTexture")
checkGlError("glGetUniformLocation")
glUniform1i(mlocation, 0)
checkGlError("glUniform1i")
self.initBuffers()
glBindVertexArray(self.vao)
checkGlError("glBindVertexArray")
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0)
# Queue Draw
glFlush()
self.queue_draw()
这是答案，这是用 OpenCV 帧测试的，它是一个 3 维数组 [width][height][RGB Color]，需要展平成一个线性数组。 OpenGL 将获取图像的宽度和高度并正确地遍历它。本指南对让它发挥作用非常有帮助：https://open.gl/drawing
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk
from OpenGL.GL import *
import numpy as np
VERTEX_SOURCE = '''
#version 330
layout (location=0) in vec3 position;
layout (location=1) in vec3 color;
layout (location=2) in vec2 texCoord;
out vec3 ourColor;
out vec2 TexCoord;
void main()
{
gl_Position = vec4(position,1.0);
ourColor = color;
TexCoord= vec2(texCoord.x,1.0-texCoord.y);
}'''
FRAGMENT_SOURCE ='''
#version 330
in vec3 ourColor;
in vec2 TexCoord;
out vec4 color;
uniform sampler2D ourTexture;
void main(){
color = texture(ourTexture, TexCoord);
};'''
recVertices = np.array([
# Positions Colors Texture Coords
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, # Top Right 0
1.0, -1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, # Bottom Right 1
-1.0, -1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, # Bottom Left 2
-1.0, 1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, # Top Left 3
1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, # Top Right 4
], dtype=np.float32)
def checkGlError(op: str):
error = glGetError()
if error is not None and error != 0:
print("after %s() glError (0x%x)", op, error)
# Based on examples:
# https://stackoverflow.com/questions/42153819/how-to-load-and-display-an-image-in-opengl-es-3-0-using-c
# https://stackoverflow.com/questions/47565884/use-of-the-gtk-glarea-in-pygobject-gtk3
class OpenGLRenderer(Gtk.GLArea):
def __init__(self):
Gtk.GLArea.__init__(self)
self.connect("realize", self.onRealize)
self.connect("render", self.onRender)
self.ctx = None
self.frame = None
self.area = None
self.shaderProgram = None
self.positionHandle = None
self.textureId = None
self.vao = None
self.vbos = None
def onRealize(self, area):
error = area.get_error()
if error != None:
print("your graphics card is probably too old : ", error)
else:
print(area, "realize... fine so far")
self.ctx = self.get_context()
self.ctx.make_current()
print("OpenGL realized", self.ctx)
def onRender(self, area, ctx):
self.render(self.frame)
return True
def setupGraphics(self):
if self.shaderProgram is None:
# Load Shaders, Create program, Setup Graphics
vertexShader = glCreateShader(GL_VERTEX_SHADER)
glShaderSource(vertexShader, VERTEX_SOURCE)
glCompileShader(vertexShader)
status = glGetShaderiv(vertexShader, GL_COMPILE_STATUS)
print("Compile vertexShader status: " + str(status == GL_TRUE))
pixelShader = glCreateShader(GL_FRAGMENT_SHADER)
glShaderSource(pixelShader, FRAGMENT_SOURCE)
glCompileShader(pixelShader)
status = glGetShaderiv(pixelShader, GL_COMPILE_STATUS)
print("Compile vertexShader status: " + str(status == GL_TRUE))
self.shaderProgram = glCreateProgram()
glAttachShader(self.shaderProgram, vertexShader)
glAttachShader(self.shaderProgram, pixelShader)
glLinkProgram(self.shaderProgram)
glBindFragDataLocation(self.shaderProgram, 0, "color")
self.positionHandle = glGetAttribLocation(self.shaderProgram, "position")
# Initalize Vertex Buffers
self.initBuffers()
def initBuffers(self):
# Initialize an buffer to store all the verticles and transfer them to the GPU
self.vao = glGenVertexArrays(1) # Generate VAO
self.vbos = glGenBuffers(1) # Generate VBO
glBindVertexArray(self.vao) # Bind the Vertex Array
glBindBuffer(GL_ARRAY_BUFFER, self.vbos) # Bind verticles array for OpenGL to use
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * len(recVertices), recVertices, GL_STATIC_DRAW)
# 1. set the vertex attributes pointers
# Position Attribute
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(0))
glEnableVertexAttribArray(0)
# Color Attribute
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(3 * sizeof(GLfloat)))
glEnableVertexAttribArray(1)
# Texture Coordinate Attribute
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(6 * sizeof(GLfloat)))
glEnableVertexAttribArray(2)
glBindVertexArray(0) # 3. Unbind VAO
def generateTexture(self, frame):
# Update Frame
self.frame = frame
# Delete previous textures to avoid memory leak
if self.textureId is not None:
glDeleteTextures(1, [self.textureId])
# If we have a frame to display
if frame is not None:
# extract array from Image
h, w, d = frame.shape
# Frame is a 3 dimentional array where shape eg. (1920, 1080, 3)
# Where it is w, h, and 3 values for color
# https://www.educba.com/numpy-flatten/
pixels = frame.flatten(order = 'C')
# Generate Texture
self.textureId = glGenTextures(1)
glBindTexture(GL_TEXTURE_2D, self.textureId) # Bind our 2D texture so that following set up will be applied
# Set texture wrapping parameter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
# Set texture Filtering parameter
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0, GL_RGB, GL_UNSIGNED_BYTE, pixels)
glGenerateMipmap(GL_TEXTURE_2D)
glBindTexture(GL_TEXTURE_2D, 0) # Unbind 2D textures
def render(self, frame):
# Set OpenGL Render Context
if self.ctx is not None and frame is not None:
self.ctx.make_current()
# Initialize Graphics
self.setupGraphics()
# Generate Texture
self.generateTexture(frame)
# Clear Screen
glClearColor(0, 0, 1, 1)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
# Use Shader Program, Bind Vertex Array and Texture
glUseProgram(self.shaderProgram)
checkGlError("glUseProgram")
glActiveTexture(GL_TEXTURE0)
checkGlError("glActiveTexture")
glBindTexture(GL_TEXTURE_2D, self.textureId)
checkGlError("glBindTexture")
mlocation = glGetUniformLocation(self.shaderProgram, "ourTexture")
checkGlError("glGetUniformLocation")
glUniform1i(mlocation, 0)
checkGlError("glUniform1i")
glBindVertexArray(self.vao)
checkGlError("glBindVertexArray")
# Render Frame
glDrawArrays(GL_TRIANGLES, 0, 3)
glDrawArrays(GL_TRIANGLES, 2, 3)
# Queue Draw
glFlush()
self.queue_draw()
在 Python 完整示例中的 GtkGLArea 中渲染纹理
import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk
import numpy as np
from OpenGL.GL import *
from OpenGL.GL import shaders
FRAGMENT_SOURCE ='''
#version 330
in vec3 Color;
in vec2 Texcoord;
out vec4 outColor;
uniform sampler2D imageTexture;
void main()
{
outColor = texture(imageTexture, Texcoord);
}'''
VERTEX_SOURCE = '''
#version 330
layout (location=0) in vec3 position;
layout (location=1) in vec3 color;
layout (location=2) in vec2 texcoord;
out vec3 Color;
out vec2 Texcoord;
void main()
{
Color = color;
Texcoord = texcoord;
gl_Position = vec4(position, 1.0);
}'''
def on_realize(self, area):
# We need to make the context current if we want to
# call GL API
area.make_current()
def on_render(area, context):
print("%s\n", glGetString(GL_VERSION))
area.make_current()
############################################
# Init Shaders
############################################
glClearColor(0, 0, 0, 1)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
VERTEX_SHADER_PROG = shaders.compileShader(VERTEX_SOURCE, GL_VERTEX_SHADER)
FRAGMENT_SHADER_PROG = shaders.compileShader(FRAGMENT_SOURCE, GL_FRAGMENT_SHADER)
shaderProgram = shaders.compileProgram(VERTEX_SHADER_PROG, FRAGMENT_SHADER_PROG)
############################################
# Init Buffers
############################################
# Create a new VAO (Vertex Array Object) and bind it
vao = glGenVertexArrays(1)
glBindVertexArray(vao)
# Generate buffers to hold our vertices
vertex_buffer = glGenBuffers(1)
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer)
# Send the data over to the buffer
vertices = np.array([
# Positions Color Texchords
1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, # Top Right 0
1.0, -1.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, # Bottom Right 1
-1.0, -1.0, 0.0, 1.0, 1.0, 1.0, 0.0, 1.0, # Bottom Left 2
-1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, # Top Left 3
1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, # Top Right 4
], dtype=np.float32)
size = sizeof(GLfloat) * len(vertices)
glBufferData(GL_ARRAY_BUFFER, size, vertices, GL_STATIC_DRAW)
# Specify the layout of the vertex data
posAttrib = glGetAttribLocation(shaderProgram, "position")
glEnableVertexAttribArray(posAttrib)
glVertexAttribPointer(posAttrib, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(0))
colAttrib = glGetAttribLocation(shaderProgram, "color")
glEnableVertexAttribArray(colAttrib)
glVertexAttribPointer(colAttrib, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(3 * sizeof(GLfloat)))
texAttrib = glGetAttribLocation(shaderProgram, "texcoord")
glEnableVertexAttribArray(texAttrib)
glVertexAttribPointer(texAttrib, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(GLfloat), ctypes.c_void_p(6 * sizeof(GLfloat)))
# Unbind the VAO first (Important)
glBindVertexArray(0)
############################################
# Render
############################################
glBindBuffer(GL_ARRAY_BUFFER, 0)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
glUseProgram(shaderProgram)
glBindVertexArray(vao)
# Load Textures
width = 2
height = 2
textureId = glGenTextures(1)
glActiveTexture(GL_TEXTURE0)
glBindTexture(GL_TEXTURE_2D, textureId)
# Black/white checkerboard
pixels = [
0.0, 0.0, 0.0, 1.0, 1.0, 1.0,
1.0, 1.0, 1.0, 0.0, 0.0, 0.0
]
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_FLOAT, pixels)
glUniform1i(glGetUniformLocation(shaderProgram, "imageTexture"), 0)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)
glDrawArrays(GL_TRIANGLES, 0, 3)
glDrawArrays(GL_TRIANGLES, 2, 3)
glBindVertexArray(0)
glUseProgram(0)
# we completed our drawing; the draw commands will be
# flushed at the end of the signal emission chain, and
# the buffers will be drawn on the window
return True
win = Gtk.Window()
area = Gtk.GLArea()
#area.set_required_version(2, 1)
#major, minor = area.get_required_version()
#print("Version " + str(major) + "." + str(minor))
area.connect('render', on_render)
area.connect('realize', on_realize)
win.connect("destroy", Gtk.main_quit)
win.add(area)
win.show_all()
Gtk.main()