gpt4 book ai didi

c++ - QOpenGLWidget 纹理映射导致黑屏

转载 作者:行者123 更新时间:2023-11-28 05:43:49 24 4
gpt4 key购买 nike

我正在尝试使用四边形作为纹理,使用 QOpenGLWidget 渲染一个简单的二维图像。但无论我尝试什么,我总是得到一个黑盒子。

我看了很多教程,我有一个像这样的简单像素缓冲区

uchar* m_pData;

它存储我的 RGB 值。这是有效的,因为我已经使用 glDrawPixles() 对其进行了测试。我将发布考虑 OpenGLWidget 的三个最重要的函数。

首先初始化GL():

void QGLImageviewer::initializeGL()
{
initializeOpenGLFunctions();

// Clear the color
float r = ((float)m_backColor.darker().red())/255.0f;
float g = ((float)m_backColor.darker().green())/255.0f;
float b = ((float)m_backColor.darker().blue())/255.0f;
glClearColor(r,g,b,1.0f);

// Set shading model.
glShadeModel(GL_SMOOTH);

// Set the viewport
glViewport(0.f, 0.f, m_origW, m_origH);

// Init. Projection Matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, m_origW, m_origH,0.0,1.0,-1.0);

// Init Modelview Matrix
glClearColor(0.f, 0.f, 0.f, 1.f);

// Enable texturing
glEnable(GL_TEXTURE_2D);


// Generate texture ID
glGenTextures(1, &m_textureID);

// Bind texture ID
glBindTexture(GL_TEXTURE_2D, m_textureID);

// Set texture parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
//glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

// Generate Texture, and assign pixles to our texture ID
if (m_pData != nullptr)
{
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_origW, m_origH, 0, GL_RGB, GL_UNSIGNED_BYTE, (GLvoid*)m_pData);
}
else
{
qCritical("Buffer is empty!!");
}

// Unbind texture
glBindTexture(GL_TEXTURE_2D, NULL);

// Check for Error
GLenum error_ = glGetError();
if (error_ != GL_NO_ERROR)
{
qCritical("Error Loading Texture!");
}

}

然后paintGL():

void QGLImageviewer::paintGL()
{
makeCurrent();

glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
// Clear Screen And Depth Buffer
glClear(GL_COLOR_BUFFER_BIT);

if (!(m_renderQtImg->isNull()))
{
//QImage image;

int imWidth = m_renderQtImg->width();
int imHeight = m_renderQtImg->height();

// The image has to be resized to fit the widget
if (imWidth != this->size().width() &&
imHeight != this->size().height())
{

imWidth = this->size().width();
imHeight = this->size().height();
}
else
{
//image = *m_renderQtImg;

imWidth = m_origW;
imHeight = m_origH;
}

if (m_textureID != 0)
{
glMatrixMode(GL_MODELVIEW);
// Remove any previous transformations
glLoadIdentity();

glPushMatrix();

// Move to rendering point
glTranslatef(0.f, 0.f, 0.f);
glColor3f(0.0f, 0.0f, 0.5f);

// Set texture ID
glBindTexture(GL_TEXTURE_2D, m_textureID);

glBegin(GL_QUADS);
glTexCoord2f(0.f, 0.f); glVertex2f(0.f, 0.f);
glTexCoord2f(1.f, 0.f); glVertex2f(imWidth, 0.f);
glTexCoord2f(1.f, 1.f); glVertex2f(imWidth, imHeight);
glTexCoord2f(0.f, 1.f); glVertex2f(0.f, imHeight);
glEnd();

//glDisable(GL_TEXTURE_2D);
glPopMatrix();
glFlush();

}
}
}

最后但同样重要的是 resizeGL():

void QGLImageviewer::resizeGL(int width, int height)
{
makeCurrent();
glViewport(0,0,(GLint)width,(GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
//gluOrtho2D(0.0, width, 0.0, height);
glOrtho(0.0, width, 0.0, height, 0.0, 1.0);

}

我正在使用 Qt5.6 和 Microsoft Visual Studio 2015 编译器。

最佳答案

妈的,问题出在

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_origW  , m_origH, 0, GL_RGB, GL_UNSIGNED_BYTE, (float*)m_pData);

我的成员变量 m_orgiWm_orgiH 被初始化为 0。毫不奇怪,我的代码不起作用。

作为记录,我将发布我的运行代码,即 QOpenGLWidget 的三个最重要的功能。 ,希望对遇到同样问题的人有用。

void QGLImageviewer::initializeGL()
{
initializeOpenGLFunctions();

float r = ((float)m_backColor.darker().red())/255.0f;
float g = ((float)m_backColor.darker().green())/255.0f;
float b = ((float)m_backColor.darker().blue())/255.0f;
glClearColor(r,g,b,1.0f);

// Generate texture ID
glGenTextures(1, &m_textureID);

// Bind texture ID
glBindTexture(GL_TEXTURE_2D, m_textureID);

if (m_pData != nullptr)
{
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_origW , m_origH, 0, GL_RGB, GL_UNSIGNED_BYTE, (float*)m_pData);
}
else
{
qCritical("Buffer is empty!!");
}

// Set texture parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); //IMPORTANT FOR NON POWER OF 2 TEXTURES
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

// Enable texturing Mapping
glEnable(GL_TEXTURE_2D);

// Enable Smooth Shading
glShadeModel(GL_SMOOTH);

// Black Background
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);

// Depth Buffer Setup
glClearDepth(1.0f);

// Enables Depth Testing
glEnable(GL_DEPTH_TEST);

// Type of depth testing to do
glDepthFunc(GL_LEQUAL);

// Really Nice Perspective Calculations
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);

// Unbind Texture
glBindTexture(GL_TEXTURE_2D, NULL);
}

现在 paintGL()

void QGLImageviewer::paintGL()
{
makeCurrent();

// Clear Screen And Depth Buffer
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, m_textureID);

glBegin(GL_QUADS);
// Drawing the quad with the texture mapped on it
//
// OpenGL 2D Coordinates
// Sticking with the Coordinate Convention mentioned here
glTexCoord2f(1.0f, 0.0f); glVertex2f(m_width, 0.0f); // vertex 1
glTexCoord2f(1.0f, 1.0f); glVertex2f(m_width, m_height); // vertex 2
glTexCoord2f(0.0f, 1.0f); glVertex2f(0.0f, m_height); // vertex 3
glTexCoord2f(0.0f, 0.0f); glVertex2f(0.0f, 0.0f); // vertex 4

glEnd();


}

resizeGL()

void QGLImageviewer::resizeGL(int width, int height)
{
makeCurrent();

m_width = width;
m_height = height;

// Compute aspect ratio of the new window
if (height == 0) height = 1; // To prevent divide by 0
GLfloat aspect = (GLfloat)width / (GLfloat)height;

// Set the viewport to cover the new window
glViewport(0, 0, width, height);

// Set the aspect ratio of the clipping area to match the viewport
glMatrixMode(GL_PROJECTION); // To operate on the Projection matrix
glLoadIdentity(); // Reset the projection matrix

glOrtho(0, m_width/ m_zoomFactor, m_height/ m_zoomFactor,0, -1, 1);

}

关于c++ - QOpenGLWidget 纹理映射导致黑屏,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36628020/

24 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com