void Widget::initializeGL()
{
qDebug() << "isValid:" << this->context()->isValid();
qDebug() << "isSharing:" << this->context()->isSharing();
qDebug() << "hasOpenGL:" << this->context()->format().hasOpenGL();
qDebug() << "Format:" << this->context()->format();
glEnable(GL_DEPTH_TEST);
QString vertexShaderSource(
"uniform mat4 modelViewMatrix;\n"
"uniform mat4 projectionMatrix;\n"
"attribute vec4 vertexPosition;\n"
"\n"
"void main(void)\n"
"{\n"
" gl_Position = projectionMatrix * modelViewMatrix * vertexPosition;\n"
"}\n");
QString fragmentShaderSource(
"precision mediump float;\n"
"\n"
"void main(void)\n"
"{\n"
"gl_FragColor = vec4(1.0, 1.0, 0.0, 1.0);\n"
"}\n");
QGLShader *vertexShader = new QGLShader(QGLShader::Vertex, this);
QGLShader *fragmentShader = new QGLShader(QGLShader::Fragment, this);
qDebug() << "After constuctor Shaders.";
qDebug() << vertexShader->log();
vertexShader->compileSourceCode(vertexShaderSource);
fragmentShader->compileSourceCode(fragmentShaderSource);
_shaderProgram = new QGLShaderProgram(this);
_shaderProgram->addShader(vertexShader);
_shaderProgram->addShader(fragmentShader);
_shaderProgram->link();
_shaderProgram->bind();
qglClearColor(Qt::gray);
_timer->start(10);
qDebug() << vertexShader->log();
}
int main( int argc, char* argv[] )
{
if( SDL_Init( SDL_INIT_VIDEO ) != 0 )
{
std::cerr << "SDL Error: " << SDL_GetError() << '\n';
return 0;
}
atexit( SDL_Quit );
SDL_Surface* surface = SDL_SetVideoMode( 800, 600, 32, SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_OPENGL );
if( surface == nullptr )
{
std::cerr << "SDL Error: " << SDL_GetError() << '\n';
exit( 1 );
}
SDL_WM_SetCaption( "OpenGL", nullptr );
glewExperimental = GL_TRUE;
GLenum glewInitError( glewInit() );
if( glewInitError != GLEW_OK )
{
std::cerr << "SDL Error: " << glewGetErrorString( glewInitError ) << '\n';
exit( 2 );
}
GLuint vertexBuffer;
glGenBuffers( 1, &vertexBuffer );
// shader code
GLuint vertexShaderHandle( glCreateShader( GL_VERTEX_SHADER ) );
std::ifstream vertexShaderSource( "Identity.vs" );
GLuint fragmentShaderHandle( glCreateShader( GL_FRAGMENT_SHADER ) );
std::ifstream fragmentShaderSource( "Identity.fs" );
glCompileShader( vertexShaderHandle );
glCompileShader( fragmentShaderHandle );
GLuint shaderProgramHandle( glCreateProgram() );
glAttachShader( shaderProgramHandle, vertexShaderHandle );
glAttachShader( shaderProgramHandle, fragmentShaderHandle );
glBindAttribLocation( vertexShaderHandle, 0, "vertex" );
glBindAttribLocation( vertexShaderHandle, 1, "color" );
glLinkProgram( shaderProgramHandle );
glDeleteShader( vertexShaderHandle );
glDeleteShader( fragmentShaderHandle );
glUseProgram( shaderProgramHandle );
glClearColor( 0.0f, 0.0f, 1.0f, 1.0f );
SDL_Event windowEvent;
while( true )
{
if( SDL_PollEvent( &windowEvent ) )
{
if( windowEvent.type == SDL_QUIT ) break;
if( windowEvent.type == SDL_KEYDOWN )
{
std::cout << "key " << static_cast< char >( windowEvent.key.keysym.sym ) << " is down\n";
}
}
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
// draw a triangle
glBegin( GL_TRIANGLES );
glVertex3f( -0.5f, 0.0f, 0.0f );
glColor4f( 1.0f, 0.0f, 0.0f, 1.0f );
glVertex3f( 0.5f, 0.0f, 0.0f );
glColor4f( 0.0f, 1.0f, 0.0f, 1.0f );
glVertex3f( 0.0f, 0.5f, 0.0f );
glColor4f( 0.0f, 0.0f, 1.0f, 1.0f );
glEnd();
SDL_GL_SwapBuffers();
std::cout << std::flush;
}
glDeleteProgram( shaderProgramHandle );
}