Example/GLSL Full Compile Linking: Difference between revisions
< Example
mNo edit summary |
Using bad coding style (ie: not initializing variables) is NOT simplifying. |
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<source lang="cpp"> | <source lang="cpp"> | ||
// Read our shaders into the appropriate buffers | //Read our shaders into the appropriate buffers | ||
std::string vertexSource = // Get source code for vertex shader. | std::string vertexSource = //Get source code for vertex shader. | ||
std::string fragmentSource = // Get source code for fragment shader. | std::string fragmentSource = //Get source code for fragment shader. | ||
// Create an empty vertex shader handle | //Create an empty vertex shader handle | ||
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER); | GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER); | ||
// Send the vertex shader source code to GL | //Send the vertex shader source code to GL | ||
// Note that std::string's .c_str is NULL character terminated. | //Note that std::string's .c_str is NULL character terminated. | ||
const GLchar *source = (const GLchar *)vertexSource.c_str(); | const GLchar *source = (const GLchar *)vertexSource.c_str(); | ||
glShaderSource(vertexShader, 1, &source, 0); | glShaderSource(vertexShader, 1, &source, 0); | ||
// Compile the vertex shader | //Compile the vertex shader | ||
glCompileShader(vertexShader); | glCompileShader(vertexShader); | ||
GLint isCompiled; | GLint isCompiled = 0; | ||
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled); | glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled); | ||
if(isCompiled == GL_FALSE) | if(isCompiled == GL_FALSE) | ||
{ | { | ||
GLint maxLength; | GLint maxLength = 0; | ||
glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength); | glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength); | ||
// The maxLength includes the NULL character | //The maxLength includes the NULL character | ||
GLchar infoLog | std::vector<GLchar> infoLog(maxLength); | ||
glGetShaderInfoLog(vertexShader, maxLength, &maxLength, infoLog); | glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &infoLog[0]); | ||
// We don't need the shader anymore. | //We don't need the shader anymore. | ||
glDeleteShader(vertexShader); | glDeleteShader(vertexShader); | ||
// In this simple program, we'll just leave | //Use the infoLog as you see fit. | ||
//In this simple program, we'll just leave | |||
return; | return; | ||
} | } | ||
// Create an empty fragment shader handle | //Create an empty fragment shader handle | ||
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER); | GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER); | ||
// Send the fragment shader source code to GL | //Send the fragment shader source code to GL | ||
// Note that std::string's .c_str is NULL character terminated. | //Note that std::string's .c_str is NULL character terminated. | ||
source = (const GLchar *)fragmentSource.c_str(); | source = (const GLchar *)fragmentSource.c_str(); | ||
glShaderSource(fragmentShader, 1, &source, 0); | glShaderSource(fragmentShader, 1, &source, 0); | ||
// Compile the fragment shader | //Compile the fragment shader | ||
glCompileShader(fragmentShader); | glCompileShader(fragmentShader); | ||
Line 51: | Line 51: | ||
if(isCompiled == GL_FALSE) | if(isCompiled == GL_FALSE) | ||
{ | { | ||
GLint maxLength; | GLint maxLength = 0; | ||
glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength); | glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength); | ||
// The maxLength includes the NULL character | //The maxLength includes the NULL character | ||
GLchar infoLog | std::vector<GLchar> infoLog(maxLength); | ||
glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, infoLog); | glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, &infoLog[0]); | ||
//We don't need the shader anymore. | |||
// We don't need the shader anymore. | |||
glDeleteShader(fragmentShader); | glDeleteShader(fragmentShader); | ||
// Either of them. Don't leak shaders. | //Either of them. Don't leak shaders. | ||
glDeleteShader(vertexShader); | glDeleteShader(vertexShader); | ||
//Use the infoLog as you see fit. | |||
// In this simple program, we'll just leave | //In this simple program, we'll just leave | ||
return; | return; | ||
} | } | ||
// Vertex and fragment shaders are successfully compiled. | //Vertex and fragment shaders are successfully compiled. | ||
// Now time to link them together into a program. | //Now time to link them together into a program. | ||
// Get a program object. | //Get a program object. | ||
GLuint program = glCreateProgram(); | GLuint program = glCreateProgram(); | ||
// Attach our shaders to our program | //Attach our shaders to our program | ||
glAttachShader(program, vertexShader); | glAttachShader(program, vertexShader); | ||
glAttachShader(program, fragmentShader); | glAttachShader(program, fragmentShader); | ||
// Link our program | //Link our program | ||
glLinkProgram(program); | glLinkProgram(program); | ||
// Note the different functions here: glGetProgram* instead of glGetShader*. | //Note the different functions here: glGetProgram* instead of glGetShader*. | ||
GLint isLinked; | GLint isLinked = 0; | ||
glGetProgramiv(program, GL_LINK_STATUS, (int *)&isLinked); | glGetProgramiv(program, GL_LINK_STATUS, (int *)&isLinked); | ||
if(isLinked == GL_FALSE) | if(isLinked == GL_FALSE) | ||
{ | { | ||
GLint maxLength; | GLint maxLength = 0; | ||
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength); | glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength); | ||
// The maxLength includes the NULL character | //The maxLength includes the NULL character | ||
GLchar infoLog | std::vector<GLchar> infoLog(maxLength); | ||
glGetProgramInfoLog(program, maxLength, &maxLength, infoLog); | glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]); | ||
//We don't need the program anymore. | |||
// We don't need the program anymore. | |||
glDeleteProgram(program); | glDeleteProgram(program); | ||
// Don't leak shaders either. | //Don't leak shaders either. | ||
glDeleteShader(vertexShader); | glDeleteShader(vertexShader); | ||
glDeleteShader(fragmentShader); | glDeleteShader(fragmentShader); | ||
// In this | //Use the infoLog as you see fit. | ||
//In this simple program, we'll just leave | |||
return; | return; | ||
} | } | ||
// Always detach shaders after a successful link. | //Always detach shaders after a successful link. | ||
glDetachShader(program, vertexShader); | glDetachShader(program, vertexShader); | ||
glDetachShader(program, fragmentShader); | glDetachShader(program, fragmentShader); | ||
</source><noinclude>[[Category:Example Code]]</noinclude> | </source><noinclude>[[Category:Example Code]]</noinclude> |
Revision as of 14:25, 6 December 2014
Full compile/link of a Vertex and Fragment Shader.
//Read our shaders into the appropriate buffers
std::string vertexSource = //Get source code for vertex shader.
std::string fragmentSource = //Get source code for fragment shader.
//Create an empty vertex shader handle
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
//Send the vertex shader source code to GL
//Note that std::string's .c_str is NULL character terminated.
const GLchar *source = (const GLchar *)vertexSource.c_str();
glShaderSource(vertexShader, 1, &source, 0);
//Compile the vertex shader
glCompileShader(vertexShader);
GLint isCompiled = 0;
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &isCompiled);
if(isCompiled == GL_FALSE)
{
GLint maxLength = 0;
glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &maxLength);
//The maxLength includes the NULL character
std::vector<GLchar> infoLog(maxLength);
glGetShaderInfoLog(vertexShader, maxLength, &maxLength, &infoLog[0]);
//We don't need the shader anymore.
glDeleteShader(vertexShader);
//Use the infoLog as you see fit.
//In this simple program, we'll just leave
return;
}
//Create an empty fragment shader handle
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
//Send the fragment shader source code to GL
//Note that std::string's .c_str is NULL character terminated.
source = (const GLchar *)fragmentSource.c_str();
glShaderSource(fragmentShader, 1, &source, 0);
//Compile the fragment shader
glCompileShader(fragmentShader);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &isCompiled);
if(isCompiled == GL_FALSE)
{
GLint maxLength = 0;
glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &maxLength);
//The maxLength includes the NULL character
std::vector<GLchar> infoLog(maxLength);
glGetShaderInfoLog(fragmentShader, maxLength, &maxLength, &infoLog[0]);
//We don't need the shader anymore.
glDeleteShader(fragmentShader);
//Either of them. Don't leak shaders.
glDeleteShader(vertexShader);
//Use the infoLog as you see fit.
//In this simple program, we'll just leave
return;
}
//Vertex and fragment shaders are successfully compiled.
//Now time to link them together into a program.
//Get a program object.
GLuint program = glCreateProgram();
//Attach our shaders to our program
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
//Link our program
glLinkProgram(program);
//Note the different functions here: glGetProgram* instead of glGetShader*.
GLint isLinked = 0;
glGetProgramiv(program, GL_LINK_STATUS, (int *)&isLinked);
if(isLinked == GL_FALSE)
{
GLint maxLength = 0;
glGetProgramiv(program, GL_INFO_LOG_LENGTH, &maxLength);
//The maxLength includes the NULL character
std::vector<GLchar> infoLog(maxLength);
glGetProgramInfoLog(program, maxLength, &maxLength, &infoLog[0]);
//We don't need the program anymore.
glDeleteProgram(program);
//Don't leak shaders either.
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
//Use the infoLog as you see fit.
//In this simple program, we'll just leave
return;
}
//Always detach shaders after a successful link.
glDetachShader(program, vertexShader);
glDetachShader(program, fragmentShader);