我想出了渲染矩形的代码,但着色器不起作用。它仍然是空白的白色。
这里我将包含重要的代码
主:
float verts[] = {
-.5f, -.5f, .0f,
-.5f, .5f, .0f,
.5f, .5f, .0f,
.5f, .5f, .0f,
.5f, -.5f, .0f,
-.5f, -.5f, .0f
};
Shader shader("basicVert.glsl", "basicFrag.glsl");
GLuint VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(verts), &verts, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
shader.enable();
Shader.cpp(类函数)
Shader::Shader(const string vpath, const string fpath) {
Shader();
current_vpath = vpath;
current_fpath = fpath;
shaderID = init();
}
Shader::Shader(const char *vpath, const char *fpath) {
Shader(string(vpath), string(fpath));
}
Shader::~Shader() {
shaderID = NULL;
glDeleteProgram(shaderID);
}
void Shader::enable() {
glUseProgram(shaderID);
}
GLuint Shader::makeVertextShader(const char* source) {
GLuint vertShaderID = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertShaderID, 1, &source, NULL);
glCompileShader(vertShaderID);
GLint r;
glGetShaderiv(vertShaderID, GL_COMPILE_STATUS, &r);
if (r == GL_FALSE) {
GLint l;
glGetShaderiv(vertShaderID, GL_INFO_LOG_LENGTH, &l);
cout << l << endl;
char *bfer = new char[l];
glGetShaderInfoLog(vertShaderID, l, &l, bfer);
cerr << "Failed to compile VERTEXT SHADER! FILE NAME: " <<
current_vpath << endl;
cerr << bfer << endl;
glDeleteShader(vertShaderID);
delete[] bfer;
return NULL;
}
return vertShaderID;
}
GLuint Shader::makeFragmentShader(const char* source) {
GLuint fragShaderID = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragShaderID, 1, &source, NULL);
glCompileShader(fragShaderID);
GLint r;
glGetShaderiv(fragShaderID, GL_COMPILE_STATUS, &r);
if (r == GL_FALSE) {
GLint l;
glGetShaderiv(fragShaderID, GL_INFO_LOG_LENGTH, &l);
char *bfer = new char[l];
glGetShaderInfoLog(fragShaderID, l, &l, bfer);
cerr << "Failed to compile FRAGMENT SHADER! FILE NAME: " <<
current_fpath << endl;
cerr << bfer << endl;
glDeleteShader(fragShaderID);
delete[] bfer;
return NULL;
}
return fragShaderID;
}
GLuint Shader::init() {
GLuint program = glCreateProgram();
const string vs = readFile(current_vpath);
const string vf = readFile(current_fpath);
const char *vertexsrc = vs.c_str();
const char *fragmentsrc = vf.c_str();
GLuint vertShaderID = this->makeVertextShader(vertexsrc);
GLuint fragShaderID = this->makeFragmentShader(fragmentsrc);
glAttachShader(program, vertShaderID);
glAttachShader(program, fragShaderID);
glLinkProgram(program);
glValidateProgram(program);
glDeleteShader(vertShaderID);
glDeleteShader(fragShaderID);
return program;
}
GLSL顶点着色器
#version 330 core
layout(location = 0) in vec3 position;
void main(){
gl_Position = position;
}
GLSL片段着色器
#version 330 core
layout(location = 0) out vec4 color;
void main(){
color = vec4(1.0, 0.0, 1.0, 1.0);
gl_FragColor = color;
}
答案 0 :(得分:2)
gl_FragColor
所以它将在Vertex Shader中,
layout(location = 0) in vec4 position;
void main()
{
gl_Position = position;
}
在FS中,
layout(location = 0) out vec4 color;
void main()
{
color = vec4(1.0, 0.0, 1.0, 1.0);
//gl_FragColor is no longer supported in modern versions of GLSL
}
答案 1 :(得分:1)
顶点和片段着色器必须如下所示:
#version 330 core
layout(location = 0) in vec3 position;
void main()
{
gl_Position = vec4( position.xyz, 1.0 );
}
#version 330 core
layout(location = 0) out vec4 color;
void main()
{
color = vec4(1.0, 0.0, 1.0, 1.0);
}
说明:
您的代码中有2个问题:
1。)虽然Vertex Shader中的顶点属性position
的类型为vec3
,但Built-in Variable (GLSL) gl_Position
的类型为vec4
}。
要么必须更改顶点属性的类型:
layout(location = 0) in vec4 position;
或者gl_Position
的作业必须进行调整:
gl_Position = vec4( position.xyz, 1.0 );
2.。在Fragment Shader中,可以使用Built-in output Variable (GLSL) gl_FragColor
:
void main()
{
gl_FragColor = [...];
}
或必须声明显式输出变量:
out vec4 color;
void main()
{
color = [...];
}
答案 2 :(得分:0)
问题似乎在于顶点着色器:您将vec3 position
传递给vec4 gl_Position
,它有效地将w坐标设置为0.正确渲染所需的是齐次坐标为1(否则w除以0除以)。尝试将代码更改为
gl_Position = vec4(position, 1.0);