OpenGL - Problems getting shaders to compile - c++

Question

Finally isolated the issue of my shader not being able to be used to it failing to compile.
Here is my shader loading routine. The first part reads in the shader:
void GLSLShader::LoadFromFile(GLenum whichShader, const string filename)
{
ifstream fp;
// Attempt to open the shader
fp.open(filename.c_str(), ios_base::in);
// If the file exists, load it
if(fp)
{
// Copy the shader into the buffer
string buffer(std::istreambuf_iterator<char>(fp), (std::istreambuf_iterator<char>()));
// Debug output to show full text of shader
errorLog.writeSuccess("Shader debug: %s", buffer.c_str());
LoadFromString(whichShader, buffer);
}
else
{
errorLog.writeError("Could not load the shader %s", filename.c_str());
}
}
After it has loaded it into a string, it sends it to be loaded:
void GLSLShader::LoadFromString(GLenum type, const string source)
{
// Create the shader
GLuint shader = glCreateShader(type);
// Convert the string
const char * ptmp = source.c_str();
glShaderSource(shader, 1, &ptmp, NULL);
// Compile the shader
glCompileShader(shader);
// Check to see if the shader has loaded
GLint status;
glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
if (status == GL_FALSE) {
GLint infoLogLength;
glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &infoLogLength);
GLchar *infoLog= new GLchar[infoLogLength];
glGetShaderInfoLog (shader, infoLogLength, NULL, infoLog);
errorLog.writeError("could not compile: %s", infoLog);
delete [] infoLog;
}
_shaders[_totalShaders++]=shader;
}
I am getting the debug output "could not compile: " and it seems that the error buffer is empty. This has been driving me crazy for the past 3 days. Does anyone see my error?
Here are the very simple shaders:
#version 330
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 color;
smooth out vec4 theColor;
void main()
{
gl_Position = position;
theColor = color;
}
#version 330
smooth in vec4 theColor;
out vec4 outputColor;
void main()
{
outputColor = theColor;
}
UPDATE
It looks like for some reason there is crap being added to the end of the shader in memory. I am not sure why. I have tried reading it in to a char* and a string. Here is the output:
<-!-> Shader: #version 330
layout (location = 0) in vec4 position;
layout (location = 1) in vec4 color;
smooth out vec4 theColor;
void main()
{
gl_Position = position;
theColor = color;
}
n
<-!-> Shader: #version 330
smooth in vec4 theColor;
out vec4 outputColor;
void main()
{
outputColor = theColor;
}
nts/Resources
Notice the 'n' at the end of the first shader and the 'nts/Resources' at the end of the second one. Any idea why?
ANOTHER UPDATE
The crap at the end was caused by an extra line at the end. I removed it and it is back to outputting the correct shader text. Still no luck thought with compiling.
I am at a loss here. The Superbible has their extensive libraries that are unoptimized and I don't need. There doesn't seem to be a damn decent shader compiler for Mac. I really don't mind how simple it is. It just needs to work with shaders. Does anyone have an example?

Answer 1

You're calling glShaderSource without supplying the length of each string in the sources array. Hence the string supplied is assumed to be terminated by a null byte ('\0'). The way you're reading the file into memory does not terminate the shader source with an additional null byte. So the GLSL compiler will read beyond the end of the shader source into random memory, where it finds… garbage.
Solution: Either add a terminating null byte, or supply the shader text lengths parameter.