我可以编译并运行该程序，但它只会在运行时创建一个没有任何内容的白色窗口。我已确保着色器文件位于同一目录中，但除了具有白色背景的窗口之外，它仍然只生成。
//
// Perspective view of a color cube using LookAt() and Frustum()
//
// Colors are assigned to each vertex and then the rasterizer interpolates
// those colors across the triangles.
//
#define _CRT_SECURE_NO_WARNINGS
#include "Angel.h"
typedef Angel::vec4 color4;
typedef Angel::vec4 point4;
const int NumVertices = 36; //(6 faces)(2 triangles/face)(3 vertices/triangle)
point4 points[NumVertices];
color4 colors[NumVertices];
// Vertices of a unit cube centered at origin, sides aligned with axes
point4 vertices[8] = {
point4( -0.5, -0.5, 0.5, 1.0 ),
point4( -0.5, 0.5, 0.5, 1.0 ),
point4( 0.5, 0.5, 0.5, 1.0 ),
point4( 0.5, -0.5, 0.5, 1.0 ),
point4( -0.5, -0.5, -0.5, 1.0 ),
point4( -0.5, 0.5, -0.5, 1.0 ),
point4( 0.5, 0.5, -0.5, 1.0 ),
point4( 0.5, -0.5, -0.5, 1.0 )
};
// RGBA olors
color4 vertex_colors[8] = {
color4( 0.0, 0.0, 0.0, 1.0 ), // black
color4( 1.0, 0.0, 0.0, 1.0 ), // red
color4( 1.0, 1.0, 0.0, 1.0 ), // yellow
color4( 0.0, 1.0, 0.0, 1.0 ), // green
color4( 0.0, 0.0, 1.0, 1.0 ), // blue
color4( 1.0, 0.0, 1.0, 1.0 ), // magenta
color4( 1.0, 1.0, 1.0, 1.0 ), // white
color4( 0.0, 1.0, 1.0, 1.0 ) // cyan
};
// Viewing transformation parameters
GLfloat radius = 1.0;
GLfloat theta = 0.0;
GLfloat phi = 0.0;
const GLfloat dr = 5.0 * DegreesToRadians;
GLuint model_view; // model-view matrix uniform shader variable location
// Projection transformation parameters
GLfloat left = -1.0, right = 1.0;
GLfloat bottom = -1.0, top = 1.0;
GLfloat zNear = 0.5, zFar = 3.0;
GLuint projection; // projection matrix uniform shader variable location
//----------------------------------------------------------------------------
// quad generates two triangles for each face and assigns colors
// to the vertices
int Index = 0;
void
quad( int a, int b, int c, int d )
{
colors[Index] = vertex_colors[a]; points[Index] = vertices[a]; Index++;
colors[Index] = vertex_colors[b]; points[Index] = vertices[b]; Index++;
colors[Index] = vertex_colors[c]; points[Index] = vertices[c]; Index++;
colors[Index] = vertex_colors[a]; points[Index] = vertices[a]; Index++;
colors[Index] = vertex_colors[c]; points[Index] = vertices[c]; Index++;
colors[Index] = vertex_colors[d]; points[Index] = vertices[d]; Index++;
}
//----------------------------------------------------------------------------
// generate 12 triangles: 36 vertices and 36 colors
void
colorcube()
{
quad( 1, 0, 3, 2 );
quad( 2, 3, 7, 6 );
quad( 3, 0, 4, 7 );
quad( 6, 5, 1, 2 );
quad( 4, 5, 6, 7 );
quad( 5, 4, 0, 1 );
}
//----------------------------------------------------------------------------
// OpenGL initialization
void
init()
{
colorcube();
// Create a vertex array object
GLuint vao;
glGenVertexArrays( 1, &vao );
glBindVertexArray( vao );
// Create and initialize a buffer object
GLuint buffer;
glGenBuffers( 1, &buffer );
glBindBuffer( GL_ARRAY_BUFFER, buffer );
glBufferData( GL_ARRAY_BUFFER, sizeof(points) + sizeof(colors),
NULL, GL_STATIC_DRAW );
glBufferSubData( GL_ARRAY_BUFFER, 0, sizeof(points), points );
glBufferSubData( GL_ARRAY_BUFFER, sizeof(points), sizeof(colors), colors );
// Load shaders and use the resulting shader program
GLuint program = InitShader( "vshader42.glsl", "fshader42.glsl" );
glUseProgram( program );
// set up vertex arrays
GLuint vPosition = glGetAttribLocation( program, "vPosition" );
glEnableVertexAttribArray( vPosition );
glVertexAttribPointer( vPosition, 4, GL_FLOAT, GL_FALSE, 0,
BUFFER_OFFSET(0) );
GLuint vColor = glGetAttribLocation( program, "vColor" );
glEnableVertexAttribArray( vColor );
glVertexAttribPointer( vColor, 4, GL_FLOAT, GL_FALSE, 0,
BUFFER_OFFSET(sizeof(points)) );
model_view = glGetUniformLocation( program, "model_view" );
projection = glGetUniformLocation( program, "projection" );
glEnable( GL_DEPTH_TEST );
glClearColor( 1.0, 1.0, 1.0, 1.0 );
}
//----------------------------------------------------------------------------
void
display( void )
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
point4 eye( radius*sin(theta)*cos(phi),
radius*sin(theta)*sin(phi),
radius*cos(theta),
1.0 );
point4 at( 0.0, 0.0, 0.0, 1.0 );
vec4 up( 0.0, 1.0, 0.0, 0.0 );
mat4 mv = LookAt( eye, at, up );
glUniformMatrix4fv( model_view, 1, GL_TRUE, mv );
mat4 p = Frustum( left, right, bottom, top, zNear, zFar );
glUniformMatrix4fv( projection, 1, GL_TRUE, p );
glDrawArrays( GL_TRIANGLES, 0, NumVertices );
glutSwapBuffers();
}
//----------------------------------------------------------------------------
void
keyboard( unsigned char key, int x, int y )
{
switch( key ) {
case 033: // Escape Key
case 'q': case 'Q':
exit( EXIT_SUCCESS );
break;
case 'x': left *= 1.1; right *= 1.1; break;
case 'X': left *= 0.9; right *= 0.9; break;
case 'y': bottom *= 1.1; top *= 1.1; break;
case 'Y': bottom *= 0.9; top *= 0.9; break;
case 'z': zNear *= 1.1; zFar *= 1.1; break;
case 'Z': zNear *= 0.9; zFar *= 0.9; break;
case 'r': radius *= 2.0; break;
case 'R': radius *= 0.5; break;
case 'o': theta += dr; break;
case 'O': theta -= dr; break;
case 'p': phi += dr; break;
case 'P': phi -= dr; break;
case ' ': // reset values to their defaults
left = -1.0;
right = 1.0;
bottom = -1.0;
top = 1.0;
zNear = 0.5;
zFar = 3.0;
radius = 1.0;
theta = 0.0;
phi = 0.0;
break;
}
glutPostRedisplay();
}
//----------------------------------------------------------------------------
void
reshape( int width, int height )
{
glViewport( 0, 0, width, height );
}
//----------------------------------------------------------------------------
int
main( int argc, char **argv )
{
glutInit( &argc, argv );
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
glutInitWindowSize( 512, 512 );
glutInitContextVersion( 3, 2 );
glutInitContextProfile( GLUT_CORE_PROFILE );
glutCreateWindow( "Color Cube" );
glewInit();
init();
glutDisplayFunc( display );
glutKeyboardFunc( keyboard );
glutReshapeFunc( reshape );
glutMainLoop();
return 0;
}
答案 0 :(得分：2)
一些想法：
将您的glewInit();替换为：
glewExperimental = GL_TRUE; // Added because of http://openglbook.com/glgenvertexarrays-access-violationsegfault-with-glew/
GLint GlewInitResult = glewInit();
if (GlewInitResult != GLEW_OK) {
printf("ERROR: %s\n", glewGetErrorString(GlewInitResult));
}
此外，您应该使用glGetError()检查OpenGL错误。请在我的博文中了解更多详情：http://blog.nobel-joergensen.com/2013/01/29/debugging-opengl-using-glgeterror/。
答案 1 :(得分：1)
一些想法：
您正在请求支持OpenGL 3.2的上下文，但是从着色器的文件名我假设您是#using GLSL 4.2？这可能是一个问题。
InitShaders是否会查找（编译）错误？
消除一种可能的错误来源。绘制全屏四边形而不是几何图形，禁用着色器等。