void Shader::SetParameter(const std::string& name, float x)
{
if (myShaderProgram)
{
EnsureGlContext();
// Enable program
GLhandleARB program = glGetHandleARB(GL_PROGRAM_OBJECT_ARB);
GLCheck(glUseProgramObjectARB(myShaderProgram));
// Get parameter location and assign it new values
GLint location = glGetUniformLocationARB(myShaderProgram, name.c_str());
if (location != -1)
GLCheck(glUniform1fARB(location, x));
else
Err() << "Parameter \"" << name << "\" not found in shader" << std::endl;
// Disable program
GLCheck(glUseProgramObjectARB(program));
}
}
unsigned int Texture::GetValidSize(unsigned int size)
{
EnsureGlContext();
// Make sure that GLEW is initialized
priv::EnsureGlewInit();
if (GLEW_ARB_texture_non_power_of_two)
{
// If hardware supports NPOT textures, then just return the unmodified size
return size;
}
else
{
// If hardware doesn't support NPOT textures, we calculate the nearest power of two
unsigned int powerOfTwo = 1;
while (powerOfTwo < size)
powerOfTwo *= 2;
return powerOfTwo;
}
}
void Shader::SetTexture(const std::string& name, const Image& texture)
{
if (myShaderProgram)
{
EnsureGlContext();
// Find the location of the variable in the shader
int location = glGetUniformLocationARB(myShaderProgram, name.c_str());
if (location == -1)
{
Err() << "Texture \"" << name << "\" not found in shader" << std::endl;
return;
}
// Store the location -> texture mapping
TextureTable::iterator it = myTextures.find(location);
if (it == myTextures.end())
{
// New entry, make sure there are enough texture units
GLint maxUnits;
GLCheck(glGetIntegerv(GL_MAX_TEXTURE_COORDS_ARB, &maxUnits));
if (myTextures.size() + 1 >= static_cast<std::size_t>(maxUnits))
{
Err() << "Impossible to use texture \"" << name << "\" for shader: all available texture units are used" << std::endl;
return;
}
myTextures[location] = &texture;
}
else
{
// Location already used, just replace the texture
it->second = &texture;
}
}
}
bool Shader::Compile(const char* vertexShaderCode, const char* fragmentShaderCode)
{
EnsureGlContext();
// First make sure that we can use shaders
if (!IsAvailable())
{
Err() << "Failed to create a shader: your system doesn't support shaders "
<< "(you should test Shader::IsAvailable() before trying to use the Shader class)" << std::endl;
return false;
}
// Destroy the shader if it was already created
if (myShaderProgram)
GLCheck(glDeleteObjectARB(myShaderProgram));
// Create the program
myShaderProgram = glCreateProgramObjectARB();
// Create the vertex shader if needed
if (vertexShaderCode)
{
// Create and compile the shader
GLhandleARB vertexShader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
GLCheck(glShaderSourceARB(vertexShader, 1, &vertexShaderCode, NULL));
GLCheck(glCompileShaderARB(vertexShader));
// Check the compile log
GLint success;
GLCheck(glGetObjectParameterivARB(vertexShader, GL_OBJECT_COMPILE_STATUS_ARB, &success));
if (success == GL_FALSE)
{
char log[1024];
GLCheck(glGetInfoLogARB(vertexShader, sizeof(log), 0, log));
Err() << "Failed to compile vertex shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(vertexShader));
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
// Attach the shader to the program, and delete it (not needed anymore)
GLCheck(glAttachObjectARB(myShaderProgram, vertexShader));
GLCheck(glDeleteObjectARB(vertexShader));
}
// Create the fragment shader if needed
if (fragmentShaderCode)
{
// Create and compile the shader
GLhandleARB fragmentShader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
GLCheck(glShaderSourceARB(fragmentShader, 1, &fragmentShaderCode, NULL));
GLCheck(glCompileShaderARB(fragmentShader));
// Check the compile log
GLint success;
GLCheck(glGetObjectParameterivARB(fragmentShader, GL_OBJECT_COMPILE_STATUS_ARB, &success));
if (success == GL_FALSE)
{
char log[1024];
GLCheck(glGetInfoLogARB(fragmentShader, sizeof(log), 0, log));
Err() << "Failed to compile fragment shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(fragmentShader));
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
// Attach the shader to the program, and delete it (not needed anymore)
GLCheck(glAttachObjectARB(myShaderProgram, fragmentShader));
GLCheck(glDeleteObjectARB(fragmentShader));
}
// Link the program
GLCheck(glLinkProgramARB(myShaderProgram));
// Check the link log
GLint success;
GLCheck(glGetObjectParameterivARB(myShaderProgram, GL_OBJECT_LINK_STATUS_ARB, &success));
if (success == GL_FALSE)
{
char log[1024];
GLCheck(glGetInfoLogARB(myShaderProgram, sizeof(log), 0, log));
Err() << "Failed to link shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
return true;
}
void Shader::Unbind() const
{
EnsureGlContext();
GLCheck(glUseProgramObjectARB(0));
}
bool Shader::CompileProgram()
{
EnsureGlContext();
// First make sure that we can use shaders
if (!IsAvailable())
{
Err() << "Failed to create a shader: your system doesn't support shaders "
<< "(you should test Shader::IsAvailable() before trying to use the Shader class)" << std::endl;
return false;
}
// Destroy the shader if it was already created
if (myShaderProgram)
GLCheck(glDeleteObjectARB(myShaderProgram));
// Define the vertex shader source (we provide it directly as it doesn't have to change)
static const char* vertexSrc =
"void main()"
"{"
" gl_TexCoord[0] = gl_MultiTexCoord0;"
" gl_FrontColor = gl_Color;"
" gl_Position = ftransform();"
"}";
// Create the program
myShaderProgram = glCreateProgramObjectARB();
// Create the shaders
GLhandleARB vertexShader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);
GLhandleARB fragmentShader = glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
// Compile them
const char* fragmentSrc = myFragmentShader.c_str();
GLCheck(glShaderSourceARB(vertexShader, 1, &vertexSrc, NULL));
GLCheck(glShaderSourceARB(fragmentShader, 1, &fragmentSrc, NULL));
GLCheck(glCompileShaderARB(vertexShader));
GLCheck(glCompileShaderARB(fragmentShader));
// Check the compile logs
GLint success;
GLCheck(glGetObjectParameterivARB(vertexShader, GL_OBJECT_COMPILE_STATUS_ARB, &success));
if (success == GL_FALSE)
{
char log[1024];
GLCheck(glGetInfoLogARB(vertexShader, sizeof(log), 0, log));
Err() << "Failed to compile shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(vertexShader));
GLCheck(glDeleteObjectARB(fragmentShader));
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
GLCheck(glGetObjectParameterivARB(fragmentShader, GL_OBJECT_COMPILE_STATUS_ARB, &success));
if (success == GL_FALSE)
{
char log[1024];
GLCheck(glGetInfoLogARB(fragmentShader, sizeof(log), 0, log));
Err() << "Failed to compile shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(vertexShader));
GLCheck(glDeleteObjectARB(fragmentShader));
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
// Attach the shaders to the program
GLCheck(glAttachObjectARB(myShaderProgram, vertexShader));
GLCheck(glAttachObjectARB(myShaderProgram, fragmentShader));
// We can now delete the shaders
GLCheck(glDeleteObjectARB(vertexShader));
GLCheck(glDeleteObjectARB(fragmentShader));
// Link the program
GLCheck(glLinkProgramARB(myShaderProgram));
// Get link log
GLCheck(glGetObjectParameterivARB(myShaderProgram, GL_OBJECT_LINK_STATUS_ARB, &success));
if (success == GL_FALSE)
{
// Oops... link errors
char log[1024];
GLCheck(glGetInfoLogARB(myShaderProgram, sizeof(log), 0, log));
Err() << "Failed to link shader:" << std::endl
<< log << std::endl;
GLCheck(glDeleteObjectARB(myShaderProgram));
myShaderProgram = 0;
return false;
}
return true;
}
