C 使用顶点缓冲区对象在OpenGL中绘制基本线
我遵循了一些,我的代码可以编译,但它不能正常工作 我希望看到一个白色的矩形,但是除了清晰的颜色之外,没有任何东西被渲染。调用C 使用顶点缓冲区对象在OpenGL中绘制基本线,c,opengl,C,Opengl,我遵循了一些,我的代码可以编译,但它不能正常工作 我希望看到一个白色的矩形,但是除了清晰的颜色之外,没有任何东西被渲染。调用glDrawArrays后,glGetError告诉我已引发错误1282。我确信问题很明显,但我看不出我错在哪里。下面是我的简单问题示例: #include <errno.h> #include <stdio.h> #include <GLFW/glfw3.h> #include <GL/gl.h> #define WIN
glDrawArrays
后,glGetError
告诉我已引发错误1282。我确信问题很明显,但我看不出我错在哪里。下面是我的简单问题示例:
#include <errno.h>
#include <stdio.h>
#include <GLFW/glfw3.h>
#include <GL/gl.h>
#define WINDOW_W 300
#define WINDOW_H 300
static const GLchar *vertex_shader_src = {
"#version 440\n"
"in vec4 position;\n"
"uniform mat4 projection;\n"
"void main()\n"
"{\n"
"\tgl_Position = projection * position;\n"
"}\n"
};
static const GLchar *fragment_shader_src = {
"#version 440\n"
"uniform vec4 color;\n"
"out vec4 outputColor;\n"
"void main()\n"
"{\n"
"outputColor = color;\n"
"}\n"
};
static GLuint program = 0;
static GLuint vao = 0;
static const GLfloat rect_vertices[] = {
5.0f, 5.0f,
WINDOW_W - 5.0f, 5.0f,
WINDOW_W - 5.0f, 5.0f,
WINDOW_W - 5.0f, WINDOW_H - 5.0f,
WINDOW_W - 5.0f, WINDOW_H - 5.0f,
5.0f, WINDOW_H - 5.0f,
5.0f, WINDOW_H - 5.0f,
5.0f, 5.0f
};
static GLuint rect_vbo = 0;
int init_program()
{
GLint status;
GLuint vertexShader;
GLuint fragmentShader;
// Initialize our vertex shader.
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertex_shader_src, NULL);
glCompileShader(vertexShader);
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &status);
if(status == GL_FALSE)
return -EINVAL;
// Initialize our fragment shader.
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragment_shader_src, NULL);
glCompileShader(fragmentShader);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &status);
if(status == GL_FALSE)
return -EINVAL;
// Initialize the program.
program = glCreateProgram();
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &status);
if(status == GL_FALSE)
return -EINVAL;
// Detach the shaders, now that the program is linked.
glDetachShader(program, vertexShader);
glDetachShader(program, fragmentShader);
// Done!
return 0;
}
void ortho_matrix(GLfloat *m, GLfloat l, GLfloat r,
GLfloat b, GLfloat t, GLfloat n, GLfloat f)
{
m[0] = 2.0f / (r - l);
m[1] = 0.0f;
m[2] = 0.0f;
m[3] = 0.0f;
m[4] = 0.0f;
m[5] = 2.0f / (t - b);
m[6] = 0.0f;
m[7] = 0.0f;
m[8] = 0.0f;
m[9] = 0.0f;
m[10] = -2.0f / (f - n);
m[11] = 0.0f;
m[12] = 0.0f;
m[13] = 0.0f;
m[14] = 0.0f;
m[15] = 1.0f;
}
int gl_color(GLfloat r, GLfloat g, GLfloat b, GLfloat a)
{
GLint colorVec;
GLfloat color[4] = {r, g, b, a};
colorVec = glGetUniformLocation(program, "color");
if(colorVec == -1)
return -EINVAL;
glUniform4fv(colorVec, 1, color);
return 0;
}
int set_uniforms(int width, int height)
{
int r;
GLint orthoMatrix;
GLfloat matrix[16];
// Set our orthographic projection uniform.
orthoMatrix = glGetUniformLocation(program, "projection");
if(orthoMatrix == -1)
return -EINVAL;
ortho_matrix(matrix, -0.5f, ((GLfloat) (width - 1)) + 0.5f,
((GLfloat) (height - 1)) + 0.5f, -0.5f, 0.0f, 1.0f);
glUniformMatrix4fv(orthoMatrix, 1, GL_FALSE, matrix);
// Set our rendering color uniform.
r = gl_color(1.0f, 1.0f, 1.0f, 1.0f);
if(r < 0)
return r;
// Done!
return 0;
}
int init_vbo()
{
glGenBuffers(1, &rect_vbo);
glBindBuffer(GL_ARRAY_BUFFER, rect_vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(rect_vertices),
rect_vertices, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
return 0;
}
int render()
{
GLenum err;
glBindBuffer(GL_ARRAY_BUFFER, rect_vbo);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, 0);
glDrawArrays(GL_LINES, 0, sizeof(rect_vertices) / sizeof(GLfloat));
err = glGetError();
while(err != GL_NO_ERROR)
{
printf("glDrawArrays err: %d\n", err);
err = glGetError();
}
glDisableVertexAttribArray(0);
return 0;
}
int main(void)
{
int r;
GLFWwindow *window;
int width;
int height;
if(!glfwInit())
return -EINVAL;
window = glfwCreateWindow(WINDOW_W, WINDOW_H,
"My Window", NULL, NULL);
if(!window)
{
glfwTerminate();
return 1;
}
glfwMakeContextCurrent(window);
r = init_program();
if(r < 0)
{
glfwTerminate();
return 1;
}
r = init_vbo();
if(r < 0)
{
glfwTerminate();
return 1;
}
while(!glfwWindowShouldClose(window))
{
// Initialize the GL viewport.
glfwGetFramebufferSize(window, &width, &height);
r = set_uniforms(width, height);
if(r < 0)
{
glfwTerminate();
return r;
}
glViewport(0, 0, width, height);
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(program);
// Call the user-provided rendering function.
r = render();
if(r < 0)
{
glfwTerminate();
return r;
}
// End GL rendering, swap the buffer, and poll for events.
glUseProgram(0);
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwTerminate();
return 0;
}
#包括
#包括
#包括
#包括
#定义窗口\u W 300
#定义窗口\u H 300
静态常量GLchar*顶点\u着色器\u src={
“#版本440\n”
“处于vec4位置;\n”
“一致mat4投影;\n”
“void main()\n”
“{\n”
“\tgl\u位置=投影*位置;\n”
“}\n”
};
静态常量GLchar*片段\u着色器\u src={
“#版本440\n”
“统一的vec4颜色;\n”
“out vec4 outputColor;\n”
“void main()\n”
“{\n”
“outputColor=color;\n”
“}\n”
};
静态GLuint程序=0;
静态胶合vao=0;
静态常量GLfloat rect_顶点[]={
5.0f,5.0f,
窗户W-5.0楼,5.0楼,
窗户W-5.0楼,5.0楼,
窗户W-5.0f,窗户H-5.0f,
窗户W-5.0f,窗户H-5.0f,
5.0楼,窗高-5.0楼,
5.0楼,窗高-5.0楼,
5.0f,5.0f
};
静态GLuint rect_vbo=0;
int init_程序()
{
闪烁状态;
GLuint顶点着色器;
胶合碎片;
//初始化顶点着色器。
vertexShader=glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader,1和vertex_shader_src,NULL);
glCompileShader(顶点着色器);
glGetShaderiv(顶点着色器、GL编译状态和状态);
如果(状态==GL\U FALSE)
返回-艾因瓦尔;
//初始化片段着色器。
fragmentShader=glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader,1和fragment_shader_src,NULL);
glCompileShader(fragmentShader);
glGetShaderiv(碎片着色器、GL\u编译状态和状态);
如果(状态==GL\U FALSE)
返回-艾因瓦尔;
//初始化程序。
program=glCreateProgram();
glAttachShader(程序,顶点着色器);
glAttachShader(程序、碎片着色器);
glLinkProgram(program);
glGetProgramiv(程序、GL链接状态和状态);
如果(状态==GL\U FALSE)
返回-艾因瓦尔;
//分离着色器,现在程序已链接。
glDetachShader(程序、顶点着色器);
glDetachShader(程序、碎片着色器);
//完成了!
返回0;
}
空心正交矩阵(GLfloat*m、GLfloat l、GLfloat r、,
GLfloat b、GLfloat t、GLfloat n、GLfloat f)
{
m[0]=2.0f/(r-l);
m[1]=0.0f;
m[2]=0.0f;
m[3]=0.0f;
m[4]=0.0f;
m[5]=2.0f/(t-b);
m[6]=0.0f;
m[7]=0.0f;
m[8]=0.0f;
m[9]=0.0f;
m[10]=-2.0f/(f-n);
m[11]=0.0f;
m[12]=0.0f;
m[13]=0.0f;
m[14]=0.0f;
m[15]=1.0f;
}
内部GLU颜色(GLfloat r、GLfloat g、GLfloat b、GLfloat a)
{
闪烁色向量;
GLfloat color[4]={r,g,b,a};
colorVec=glGetUniformLocation(程序,“颜色”);
如果(colorVec==-1)
返回-艾因瓦尔;
glUniform4fv(colorVec,1,color);
返回0;
}
int set_制服(int宽度、int高度)
{
INTR;
闪烁正交矩阵;
GLfloat矩阵[16];
//将正交投影设置为一致。
正交矩阵=glGetUniformLocation(程序,“投影”);
if(正交矩阵==-1)
返回-艾因瓦尔;
正交矩阵(矩阵,-0.5f,((GLfloat)(宽度-1))+0.5f,
((GLfloat)(高度-1))+0.5f、-0.5f、0.0f、1.0f);
glUniformMatrix4fv(正交矩阵,1,GL_假,矩阵);
//将渲染颜色设置为均匀。
r=gl_颜色(1.0f、1.0f、1.0f、1.0f);
if(r<0)
返回r;
//完成了!
返回0;
}
int init_vbo()
{
glGenBuffers(1,&rectvbo);
glBindBuffer(GL_数组_BUFFER,rect_vbo);
glBufferData(GL_数组_缓冲区,sizeof(rect_顶点),
矩形顶点,GL静态绘制);
glBindBuffer(GL_数组_BUFFER,0);
返回0;
}
int render()
{
肩胛盂;
glBindBuffer(GL_数组_BUFFER,rect_vbo);
GlenableVertexAttributeArray(0);
glvertexattributepointer(0,2,GL_FLOAT,GL_FALSE,0,0);
gldrawArray(GL_线,0,sizeof(rect_顶点)/sizeof(GLfloat));
err=glGetError();
while(err!=GL\u无错误)
{
printf(“glDrawArrays错误:%d\n”,错误);
err=glGetError();
}
glDisableVertexAttributeArray(0);
返回0;
}
内部主(空)
{
INTR;
GLFWwindow*窗口;
整数宽度;
内部高度;
如果(!glfwInit())
返回-艾因瓦尔;
窗口=glfwCreateWindow(窗口W、窗口H、,
“我的窗口”,空,空);
如果(!窗口)
{
glfwTerminate();
返回1;
}
glfwMakeContextCurrent(窗口);
r=init_程序();
if(r<0)
{
glfwTerminate();
返回1;
}
r=init_vbo();
if(r<0)
{
glfwTerminate();
返回1;
}
而(!glfwWindowShouldClose(窗口))
{
//初始化GL视口。
glfwGetFramebufferSize(窗口、宽度和高度);
r=套装制服(宽度、高度);
if(r<0)
{
glfwTerminate();
返回r;
}
glViewport(0,0,宽度,高度);
glClearColor(0.0f、0.0f、0.0f、1.0f);
glClear(GLU颜色缓冲位);
glUseProgram(程序);
//调用用户提供的呈现函数。
r=render();
if(r<0)
{
glfwTerminate();
返回r;
}
//结束GL渲染、交换缓冲区并轮询事件。
glUseProgram(0);
glfwSwapBuffers(窗口);
glfwPollEvents();
}
glfwTerminate();
返回0;
}
我试着搜索这个错误号,我发现了,例如,但我真的看不到任何方法来找出具体的错误
我做错了什么,或者,我如何才能发现呢?我实际上发现了什么是错的。这个错误实际上发生了很多次
glDrawArrays(GL_LINES, 0, sizeof(rect_vertices) / sizeof(GLfloat));
glDrawArrays(GL_LINES, 0, sizeof(rect_vertices) / (2 * sizeof(GLfloat)));