编辑2：
目前的代码运行良好！谢谢大家。我在最下面包含了我的着色器代码供参考，但实际上它们目前完全没有作用。
我正在尝试开始使用OpenGL 4.1，并且仍处于开发的早期阶段。目前，在此项目中我甚至还没有真正使用4.0的功能，因此这同样是一个关于OpenGL 3的问题。
我最初的目标是简单地处理两个类来处理VAO和VBO。我有一些误解，但终于克服了空白屏幕的问题。
/* THIS CODE IS NOW FULLY FUNCTIONAL */
/* well, fully is questionable lol, should work out of the box with glew and glfw */
/* A simple function that will read a file into an allocated char pointer buffer */
/* Borrowed from OpenGL.org tutorial */
char* filePull(char *file)
{
FILE *fptr;
long length;
char *buf;
fptr = fopen(file, "r"); /* Open file for reading */
if (!fptr) /* Return NULL on failure */
return NULL;
fseek(fptr, 0, SEEK_END); /* Seek to the end of the file */
length = ftell(fptr); /* Find out how many bytes into the file we are */
buf = (char*)malloc(length+1); /* Allocate a buffer for the entire length of the file and a null terminator */
fseek(fptr, 0, SEEK_SET); /* Go back to the beginning of the file */
fread(buf, length, 1, fptr); /* Read the contents of the file in to the buffer */
fclose(fptr); /* Close the file */
buf[length] = 0; /* Null terminator */
return buf; /* Return the buffer */
}
class VBO
{
public:
GLuint buffer;
bool isBound;
vector<void*> belongTo;
vector<GLfloat> vertex;
GLenum usage;
void Load()
{ glBufferData(GL_ARRAY_BUFFER, vertex.size()*sizeof(GLfloat), &vertex[0], usage); }
void Create(void* parent)
{
glGenBuffers(1, &buffer);
glBindBuffer(GL_ARRAY_BUFFER, buffer);
glBufferData(GL_ARRAY_BUFFER, vertex.size()*sizeof(GLfloat), &vertex[0], usage);
isBound=true;
belongTo.push_back(parent);
}
void Activate()
{
if(!isBound) glBindBuffer(GL_ARRAY_BUFFER, buffer);
isBound=true;
}
void Deactivate(){ glBindBuffer(GL_ARRAY_BUFFER, 0); }
VBO() : isBound(false), usage(GL_STATIC_DRAW)
{ }
~VBO() { }
private:
};
class VAO
{
public:
GLuint buffer;
string key;
unsigned long long cursor;
vector<VBO> child;
void Create()
{
glGenVertexArrays(1, &buffer);
for(unsigned int i=0; i<child.size(); i++)
child[i].Create(this);
}
void Activate()
{
glBindVertexArray(buffer);
for(unsigned int i=0; i<child.size(); i++)
child[i].Activate();
}
void Release(){ glBindVertexArray(0); }
void Remove(){ glDeleteVertexArrays(1, &buffer); }
VAO() : buffer(1) { }
~VAO() { }
private:
};
int main()
{
int width=640, height=480, frame=1; bool running = true;
glfwInit();
if( !glfwOpenWindow( width, height, 0, 0, 0, 0, 0, 0, GLFW_WINDOW ) )
{ glfwTerminate(); return 13; }
glfwSetWindowTitle("Genesis");
glewInit();
cout<<(GLEW_VERSION_4_1?"yes":"no"); //yes
GLchar *vsource, *fsource;
GLuint _vs, _fs;
GLuint Shader;
vsource = filePull("base.vert");
fsource = filePull("base.frag");
/* Compile Shaders */
_vs = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(_vs, 1, (const GLchar**)&vsource, 0);
glCompileShader(_vs);
// glGetShaderiv(_vs, GL_COMPILE_STATUS, &IsCompiled_VS);
_fs = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(_fs, 1, (const GLchar**)&fsource, 0);
glCompileShader(_fs);
/***************** ^ Vertex | Fragment v *********************/
glAttachShader(Shader, _vs);
glAttachShader(Shader, _fs);
// glGetShaderiv(_fs, GL_COMPILE_STATUS, &IsCompiled_FS);
glBindAttribLocation(Shader, 0, "posIn");
glLinkProgram(Shader);
// glGetProgramiv(shaderprogram, GL_LINK_STATUS, (int *)&IsLinked);
VAO Object3D;
VBO myVBO[3];
glUseProgram(Shader);
for(int i=0; i<9; i++)
myVBO[0].vertex.push_back((i%9)*.11); //Arbitrary vertex values
Object3D.child.push_back(myVBO[0]);
Object3D.Create();
glClearColor( 0.7f, 0.74f, 0.77f, 0.0f ); //Black got lonely
int i=0; while(running)
{
frame++;
glfwGetWindowSize( &width, &height );
height = height > 0 ? height : 1;
glViewport( 0, 0, width, height );
glClear( GL_COLOR_BUFFER_BIT );
/* Bind, Draw, Unbind */
Object3D.Activate();
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, false, 0, 0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 9);
Object3D.Release();
glfwSwapBuffers();
// exit if ESC was pressed or window was closed
running = !glfwGetKey(GLFW_KEY_ESC) && glfwGetWindowParam( GLFW_OPENED);
i++;
}
glUseProgram(0); glDisableVertexAttribArray(0);
glDetachShader(Shader, _vs); glDetachShader(Shader, _fs);
glDeleteProgram(Shader); glDeleteShader(_vs); glDeleteShader(_fs);
glDeleteVertexArrays(1, &Object3D.buffer);
glfwTerminate();
return 0;
}
基本上，我只是希望在屏幕上得到任何东西。我正在使用glfw和glew。我是完全遗漏了一些东西还是只需要更正一些东西？目前代码有些混乱，抱歉。
base.vert
// Fragment Shader – file "base.vert"
#version 300
in vec3 posIn;
out vec4 colorOut;
void main(void)
{
gl_Position = vec4(posIn, 1.0);
colorOut = vec4(3.0,6.0,4.0,1.0);
}
base.frag
// Vertex Shader – file "base.frag"
#version 300
out vec3 colorOut;
void main(void)
{
colorOut = vec3(1.0,10,1.0);
}