Qt OpenGL纹理垃圾
我有一个问题,纹理-它加载正确的图像,但渲染垃圾的几何体。几何体本身绘制得很好(一个简单的三角形),但无论我加载哪个纹理,它都只是在三角形上吐出随机图案 我在MacOSX上使用g++4.2.1,使用Qt4.7和OpenGL 首先,这里是控制台输出:Qt OpenGL纹理垃圾,qt,opengl,texturing,Qt,Opengl,Texturing,我有一个问题,纹理-它加载正确的图像,但渲染垃圾的几何体。几何体本身绘制得很好(一个简单的三角形),但无论我加载哪个纹理,它都只是在三角形上吐出随机图案 我在MacOSX上使用g++4.2.1,使用Qt4.7和OpenGL 首先,这里是控制台输出: BallGLWidget::initializeGL called Image format is GL_RGB Checking textures... glGetError enum value: GL_NO_ERROR 此外,我的着色器初始
BallGLWidget::initializeGL called
Image format is GL_RGB
Checking textures...
glGetError enum value: GL_NO_ERROR
此外,我的着色器初始化日志代码没有注册任何错误
OpenGL初始化函数:
void BallGLWidget::initializeGL()
{
cout << "BallGLWidget::initializeGL called" << endl;
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
initializeShaders();
checkOpenGLError();
glEnableVertexAttribArray(VERTEX_POS_NUM);
glEnableVertexAttribArray(TEX_POS_NUM);
glBindAttribLocation(programHandle, VERTEX_POS_NUM, VERTEX_POS_ATTRIB_NAME);
glBindAttribLocation(programHandle, TEX_POS_NUM, TEX_COORD_ATTRIB_NAME);
//this MUST be called AFTER glBindAttribLocation
glLinkProgram(programHandle);
//FIXME:-----------DEBUG-----------
printProgramInfoLog(programHandle);
//-----------END-DEBUG-----------
glUseProgram(programHandle);
//FIXME:-----------DEBUG-----------
printProgramInfoLog(programHandle);
//-----------END-DEBUG-----------
checkOpenGLError();
samplerUniformLocation =
glGetUniformLocation(programHandle, BALL_SAMPLER_NAME);
glUniform1f(samplerUniformLocation, 0);
glActiveTexture(GL_TEXTURE0);
ball_texture_handle = loadTexture(BALL_IMAGE_PATH);
//bind it in initialization because we're only using
//1 texture in the program
glBindTexture(GL_TEXTURE_2D, ball_texture_handle);
}
GLuint BallGLWidget::loadTexture(const char* filenamePtr)
{
//create & prepare a temporary texture handle that will be copied to
//DesktopMain::ball_texture_handle after this function returns
GLuint texHandle;
glGenTextures(1, &texHandle);
glBindTexture(GL_TEXTURE_2D, texHandle);
QImage* img = new QImage();
if(!img->load(filenamePtr))
{
//error loading image, handle error
cerr << "ERROR LOADING TEXTURE" << endl;
}
//This is the Qt way- its commented out for conventional OpenGL code
//bind the texture to the current context
//GLuint texHandle = bindTexture(*img);
GLenum openglImageFormat;
QImage::Format imgFormat = img->format();
switch(imgFormat)
{
case QImage::Format_RGB32:
openglImageFormat = GL_RGB;
cout << "Image format is GL_RGB" << endl;
break;
case QImage::Format_ARGB32:
openglImageFormat = GL_RGBA;
cout << "Image format is GL_RGBA" << endl;
break;
//handle this case the same as ARGB32
case QImage::Format_ARGB32_Premultiplied:
openglImageFormat = GL_RGBA;
cout << "Image format is GL_RGBA (premultiplied)" << endl;
break;
case QImage::Format_Invalid:
cerr << "ERROR: INVALID IMAGE FORMAT" << endl;
return -1;
break;
default:
cerr << "ERROR: UNRECOGNIZED IMAGE FORMT" << endl;
return -1;
break;
}
//use tightly packed pixel values
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
//use linear filtering
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB,
img->width(), img->height(), 0, openglImageFormat,
GL_UNSIGNED_BYTE, img->bits());
cerr << "Checking textures..." << endl;
checkOpenGLError();
delete img;
return texHandle;
}
片段着色器:
varying vec2 tex_coord_output;
uniform sampler2D ballsampler;
void main()
{
gl_FragColor = texture2D(ballsampler, tex_coord_output);
}
编辑:
按要求提供程序的屏幕截图
编辑:
属性位置已关闭,因为只有在链接程序对象之前调用GLBindAttriblLocation时,GLBindAttriblLocation才会起作用(http://www.opengl.org/sdk/docs/man/xhtml/glBindAttribLocation.xml). 我相应地修改了上面的代码,但程序仍然如下所示(纹理仍然存在问题…):
我得到以下结果:
分解它,尝试一些简单的方法: 垂直glsl
#version 120
uniform mat4 projection;
uniform mat4 modelview;
attribute vec2 position;
attribute vec2 texcoord;
varying vec2 fragTexCoord;
void main(void)
{
fragTexCoord = texcoord;
gl_Position = projection * modelview * vec4( position, 0.0, 1.0 );
}
frag.glsl
#version 120
uniform sampler2D texture;
varying vec2 fragTexCoord;
void main(void)
{
gl_FragColor = texture2D( texture, fragTexCoord );
}
main.cpp
#include <GL/glew.h>
#include <GL/glut.h>
#include <cstdlib>
#include <stdexcept>
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;
GLuint CreateShader( const GLenum& aShaderType, const string& aShaderSource )
{
GLuint shader = glCreateShader( aShaderType );
const GLchar* shaderString = aShaderSource.c_str();
GLint shaderLength = aShaderSource.size();
glShaderSource( shader, 1, &shaderString, &shaderLength );
glCompileShader( shader );
GLint compiled;
glGetShaderiv( shader, GL_COMPILE_STATUS, &compiled );
if( GL_FALSE == compiled )
{
// compile failure, dump log
GLint loglen;
glGetShaderiv( shader, GL_INFO_LOG_LENGTH , &loglen);
vector< char > log( loglen );
glGetShaderInfoLog( shader, loglen, NULL, &log[0] );
string type;
switch( aShaderType )
{
case GL_VERTEX_SHADER: type = "GL_VERTEX_SHADER"; break;
case GL_FRAGMENT_SHADER: type = "GL_FRAGMENT_SHADER"; break;
default: type = "UNKNOWN SHADER"; break;
}
stringstream err;
err << "*** " << type << " ***" << endl;
err << aShaderSource;
err << "*** Compilation Log ***" << endl;
err << string( log.begin(), log.end() );
throw std::logic_error( err.str() );
}
return shader;
}
GLuint CreateProgram( const string& aVertexShader, const string& aFragmentShader )
{
GLuint vert = CreateShader( GL_VERTEX_SHADER, aVertexShader );
GLuint frag = CreateShader( GL_FRAGMENT_SHADER, aFragmentShader );
GLuint program = glCreateProgram();
glAttachShader( program, vert );
glAttachShader( program, frag );
glLinkProgram( program );
glDeleteShader( vert );
glDeleteShader( frag );
GLint linked;
glGetProgramiv( program, GL_LINK_STATUS, &linked );
if( GL_FALSE == linked )
{
// link failure, dump log
GLint loglen;
glGetProgramiv( program, GL_INFO_LOG_LENGTH , &loglen);
vector< char > log( loglen );
glGetProgramInfoLog( program, loglen, NULL, &log[0] );
stringstream err;
err << "*** Link log ***" << endl;
err << string( log.begin(), log.end() );
throw std::logic_error( err.str() );
}
return program;
}
string LoadFile( const string& filename )
{
ifstream infile(filename.c_str(), ios::binary);
istreambuf_iterator<char> begin(infile), end;
return string(begin, end);
}
GLuint prog = 0;
GLuint tex = 0;
void init()
{
GLenum glewError = glewInit();
if( GLEW_OK != glewError )
{
stringstream err;
err << "GLEW error: " << glewGetErrorString(glewError) << endl;
throw std::logic_error( err.str() );
}
cout << "GLEW_VERSION : " << glewGetString(GLEW_VERSION) << endl;
cout << "GL_VERSION : " << glGetString(GL_VERSION) << endl;
cout << "GLSL VERSION : " << glGetString(GL_SHADING_LANGUAGE_VERSION) << endl;
cout << "GL_VENDOR : " << glGetString(GL_VENDOR) << endl;
cout << "GL_RENDERER : " << glGetString(GL_RENDERER) << endl;
if( !GLEW_VERSION_2_1 )
{
stringstream err;
err << "OpenGL 2.1 or better required for GLSL support." << endl;
throw std::logic_error( err.str() );
}
// load shaders
string vert = LoadFile( "vert.glsl" );
string frag = LoadFile( "frag.glsl" );
prog = CreateProgram( vert, frag );
// create random texture
const unsigned int width = 32;
const unsigned int height = 32;
const unsigned int channels = 3;
unsigned char buffer[ width * height * channels ];
for( unsigned int i = 0; i < width * height; ++i )
{
buffer[i*channels + 0] = rand()%255;
buffer[i*channels + 1] = rand()%255;
buffer[i*channels + 2] = rand()%255;
}
// upload texture data
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
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_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, channels, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, buffer);
}
struct Vertex
{
Vertex() : x(0), y(0), s(0), t(0) {}
Vertex( float _x, float _y, float _s, float _t ) : x(_x), y(_y), s(_s), t(_t) {}
float x, y;
float s, t;
};
void display()
{
static float currentTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;
float newTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;
float frameTime = newTime - currentTime;
currentTime = newTime;
vector< Vertex > verts;
verts.push_back( Vertex( -1, -1, 0, 0 ) );
verts.push_back( Vertex( 1, -1, 1, 0 ) );
verts.push_back( Vertex( 1, 1, 1, 1 ) );
verts.push_back( Vertex( -1, 1, 0, 1 ) );
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
static float angle = 0;
angle += 60 * frameTime;
glRotatef( angle, 0, 0, 1 );
glScalef( 5, 5, 5 );
glUseProgram( prog );
// load uniforms
GLfloat projection[16];
glGetFloatv( GL_PROJECTION_MATRIX, projection );
GLint projection_loc = glGetUniformLocation( prog, "projection" );
glUniformMatrix4fv( projection_loc, 1, GL_FALSE, projection );
GLfloat modelview[16];
glGetFloatv( GL_MODELVIEW_MATRIX, modelview );
GLint modelview_loc = glGetUniformLocation( prog, "modelview" );
glUniformMatrix4fv( modelview_loc, 1, GL_FALSE, modelview );
GLint texture_loc = glGetUniformLocation( prog, "texture" );
glUniform1i( texture_loc, 0 );
glActiveTexture( GL_TEXTURE0 );
glBindTexture( GL_TEXTURE_2D, tex );
// load attributes
GLint position_loc = glGetAttribLocation( prog, "position" );
glVertexAttribPointer( position_loc, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &verts[0].x );
glEnableVertexAttribArray( position_loc );
GLint texcoord_loc = glGetAttribLocation( prog, "texcoord" );
glVertexAttribPointer( texcoord_loc, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &verts[0].s );
glEnableVertexAttribArray( texcoord_loc );
// render
glDrawArrays( GL_QUADS, 0, verts.size() );
glDisableVertexAttribArray( position_loc );
glDisableVertexAttribArray( texcoord_loc );
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
double aspect = (double)w / (double)h;
glOrtho(-10*aspect, 10*aspect, -10, 10, -1, 1);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitWindowSize(800,600);
glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutCreateWindow("GLSL");
try
{
init();
}
catch( std::exception& e )
{
cout << "Init failure: " << endl << e.what() << endl;
return EXIT_FAILURE;
}
glutDisplayFunc(display);
glutIdleFunc(display);
glutReshapeFunc(reshape);
glutMainLoop();
return EXIT_SUCCESS;
}
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使用名称空间std;
GLuint CreateShader(常量GLenum和aShaderType、常量字符串和aShaderSource)
{
GLuint着色器=glCreateShader(aShaderType);
const GLchar*shaderString=aShaderSource.c_str();
GLint shaderLength=aShaderSource.size();
glShaderSource(着色器,1,&shaderString,&shaderLength);
glCompileShader(着色器);
闪烁编译;
glGetShaderiv(着色器、GL\u编译状态和编译状态);
如果(GL_FALSE==已编译)
{
//编译失败,转储日志
闪烁loglen;
glGetShaderiv(着色器、GL\u INFO\u LOG\u LENGTH和loglen);
向量log(loglen);
glGetShaderInfoLog(着色器、loglen、NULL和log[0]);
字符串类型;
开关(aShaderType)
{
案例GL_顶点着色器:type=“GL_顶点着色器”中断;
案例GL\u FRAGMENT\u着色器:type=“GL\u FRAGMENT\u着色器”中断;
默认值:type=“UNKNOWN SHADER”中断;
}
弦乐;
err您对GLTEXAGE2D()的调用指定内部格式为GL_RGB,但上面的代码表示该格式可能是RGBA图像。这两个图像必须匹配。如果您的图像有4个通道,则内部格式需要为GL_RGBA(或另一个4通道格式).谢谢-这可能是解决方案的一部分,但没有解决。我仍然遇到顶点/碎片着色器有助于理解的相同问题。它们编译的事实没有多大帮助。此外,问题的屏幕截图也有助于确定解决方案。纹理大小如何?请显示纹理本身。我正在尝试的纹理render是一个非常简单的红色圆圈。这里:你能解释一下我自己的代码中到底有什么问题,或者到底要修改什么吗?
#include <GL/glew.h>
#include <GL/glut.h>
#include <cstdlib>
#include <stdexcept>
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
using namespace std;
GLuint CreateShader( const GLenum& aShaderType, const string& aShaderSource )
{
GLuint shader = glCreateShader( aShaderType );
const GLchar* shaderString = aShaderSource.c_str();
GLint shaderLength = aShaderSource.size();
glShaderSource( shader, 1, &shaderString, &shaderLength );
glCompileShader( shader );
GLint compiled;
glGetShaderiv( shader, GL_COMPILE_STATUS, &compiled );
if( GL_FALSE == compiled )
{
// compile failure, dump log
GLint loglen;
glGetShaderiv( shader, GL_INFO_LOG_LENGTH , &loglen);
vector< char > log( loglen );
glGetShaderInfoLog( shader, loglen, NULL, &log[0] );
string type;
switch( aShaderType )
{
case GL_VERTEX_SHADER: type = "GL_VERTEX_SHADER"; break;
case GL_FRAGMENT_SHADER: type = "GL_FRAGMENT_SHADER"; break;
default: type = "UNKNOWN SHADER"; break;
}
stringstream err;
err << "*** " << type << " ***" << endl;
err << aShaderSource;
err << "*** Compilation Log ***" << endl;
err << string( log.begin(), log.end() );
throw std::logic_error( err.str() );
}
return shader;
}
GLuint CreateProgram( const string& aVertexShader, const string& aFragmentShader )
{
GLuint vert = CreateShader( GL_VERTEX_SHADER, aVertexShader );
GLuint frag = CreateShader( GL_FRAGMENT_SHADER, aFragmentShader );
GLuint program = glCreateProgram();
glAttachShader( program, vert );
glAttachShader( program, frag );
glLinkProgram( program );
glDeleteShader( vert );
glDeleteShader( frag );
GLint linked;
glGetProgramiv( program, GL_LINK_STATUS, &linked );
if( GL_FALSE == linked )
{
// link failure, dump log
GLint loglen;
glGetProgramiv( program, GL_INFO_LOG_LENGTH , &loglen);
vector< char > log( loglen );
glGetProgramInfoLog( program, loglen, NULL, &log[0] );
stringstream err;
err << "*** Link log ***" << endl;
err << string( log.begin(), log.end() );
throw std::logic_error( err.str() );
}
return program;
}
string LoadFile( const string& filename )
{
ifstream infile(filename.c_str(), ios::binary);
istreambuf_iterator<char> begin(infile), end;
return string(begin, end);
}
GLuint prog = 0;
GLuint tex = 0;
void init()
{
GLenum glewError = glewInit();
if( GLEW_OK != glewError )
{
stringstream err;
err << "GLEW error: " << glewGetErrorString(glewError) << endl;
throw std::logic_error( err.str() );
}
cout << "GLEW_VERSION : " << glewGetString(GLEW_VERSION) << endl;
cout << "GL_VERSION : " << glGetString(GL_VERSION) << endl;
cout << "GLSL VERSION : " << glGetString(GL_SHADING_LANGUAGE_VERSION) << endl;
cout << "GL_VENDOR : " << glGetString(GL_VENDOR) << endl;
cout << "GL_RENDERER : " << glGetString(GL_RENDERER) << endl;
if( !GLEW_VERSION_2_1 )
{
stringstream err;
err << "OpenGL 2.1 or better required for GLSL support." << endl;
throw std::logic_error( err.str() );
}
// load shaders
string vert = LoadFile( "vert.glsl" );
string frag = LoadFile( "frag.glsl" );
prog = CreateProgram( vert, frag );
// create random texture
const unsigned int width = 32;
const unsigned int height = 32;
const unsigned int channels = 3;
unsigned char buffer[ width * height * channels ];
for( unsigned int i = 0; i < width * height; ++i )
{
buffer[i*channels + 0] = rand()%255;
buffer[i*channels + 1] = rand()%255;
buffer[i*channels + 2] = rand()%255;
}
// upload texture data
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
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_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, channels, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, buffer);
}
struct Vertex
{
Vertex() : x(0), y(0), s(0), t(0) {}
Vertex( float _x, float _y, float _s, float _t ) : x(_x), y(_y), s(_s), t(_t) {}
float x, y;
float s, t;
};
void display()
{
static float currentTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;
float newTime = glutGet(GLUT_ELAPSED_TIME) / 1000.0f;
float frameTime = newTime - currentTime;
currentTime = newTime;
vector< Vertex > verts;
verts.push_back( Vertex( -1, -1, 0, 0 ) );
verts.push_back( Vertex( 1, -1, 1, 0 ) );
verts.push_back( Vertex( 1, 1, 1, 1 ) );
verts.push_back( Vertex( -1, 1, 0, 1 ) );
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
static float angle = 0;
angle += 60 * frameTime;
glRotatef( angle, 0, 0, 1 );
glScalef( 5, 5, 5 );
glUseProgram( prog );
// load uniforms
GLfloat projection[16];
glGetFloatv( GL_PROJECTION_MATRIX, projection );
GLint projection_loc = glGetUniformLocation( prog, "projection" );
glUniformMatrix4fv( projection_loc, 1, GL_FALSE, projection );
GLfloat modelview[16];
glGetFloatv( GL_MODELVIEW_MATRIX, modelview );
GLint modelview_loc = glGetUniformLocation( prog, "modelview" );
glUniformMatrix4fv( modelview_loc, 1, GL_FALSE, modelview );
GLint texture_loc = glGetUniformLocation( prog, "texture" );
glUniform1i( texture_loc, 0 );
glActiveTexture( GL_TEXTURE0 );
glBindTexture( GL_TEXTURE_2D, tex );
// load attributes
GLint position_loc = glGetAttribLocation( prog, "position" );
glVertexAttribPointer( position_loc, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &verts[0].x );
glEnableVertexAttribArray( position_loc );
GLint texcoord_loc = glGetAttribLocation( prog, "texcoord" );
glVertexAttribPointer( texcoord_loc, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), &verts[0].s );
glEnableVertexAttribArray( texcoord_loc );
// render
glDrawArrays( GL_QUADS, 0, verts.size() );
glDisableVertexAttribArray( position_loc );
glDisableVertexAttribArray( texcoord_loc );
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
double aspect = (double)w / (double)h;
glOrtho(-10*aspect, 10*aspect, -10, 10, -1, 1);
}
int main(int argc, char **argv)
{
glutInit(&argc, argv);
glutInitWindowSize(800,600);
glutInitDisplayMode(GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE);
glutCreateWindow("GLSL");
try
{
init();
}
catch( std::exception& e )
{
cout << "Init failure: " << endl << e.what() << endl;
return EXIT_FAILURE;
}
glutDisplayFunc(display);
glutIdleFunc(display);
glutReshapeFunc(reshape);
glutMainLoop();
return EXIT_SUCCESS;
}