How can I check glsl code in command line? - opengl

Question

I'm editing shaders for Minecraft pe on my phone via ssh using a KDE terminal on my computer.
Syntax highlighting works good, but it does not show even simplest errors.
For example in this code below I have at list two errors, mostly lexical
vec4 no`rm`alColor;
void main(){
nomralColor = vec3(1.0,1.0,1.0,1.0);//vec3 != vec4
gl_FragColor = nomralColor;//normalColorl != nomralColor
}
Is there any possible way to check glsl code for simplest (at list lexical) errors using one of available command line code editors (nano/vim/micro)?

Answer 1

I suggest making a little tool you can use to check. The following code just prints out the error in the console window. You could be coding in C++ or Java for Android, I'll give you my C++ example because all the OpenGL calls are the same in Java too.
It's pretty short really, you just use glCreateShader() and glCompileShader() to try to compile it, followed by glGetShaderInfoLog() to give you the error message(s).
//tell openGL to do all the work for us
bool compileShader(GLuint shaderID, std::string shaderCode) {
// Compile Shader
glShaderSource(shaderID, 1, (const char* const*)shaderCode.c_str(), NULL);
glCompileShader(shaderID);
// Check Shader
GLint Result = GL_FALSE;
int InfoLogLength;
glGetShaderiv(shaderID, GL_COMPILE_STATUS, &Result);
glGetShaderiv(shaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
// Do we have an error message?
if (InfoLogLength > 0){
std::vector<char> shaderErrorMessage(InfoLogLength + 1);
// Get the message text
glGetShaderInfoLog(shaderID, InfoLogLength, NULL, &shaderErrorMessage[0]);
#ifdef DBG_SHADER
printf("Compilation error:\n%s", &shaderErrorMessage[0]);
#endif
return false;
}
return true;
}
and the usage of that function is, given a string of code called FragmentShaderCode
GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);
bool succeeded = compileShader(FragmentShaderID, FragmentShaderCode);