/*
......... 2015 Ivan Mahonin
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <cassert>
#include <iostream>
#include "shaders.h"
using namespace std;
Shaders::Shaders():
simple_vertex_id(),
simpleProgramId(),
color_fragment_id(),
colorProgramId(),
colorUniform()
{
// simple
const char *simpleVertexSource =
"in vec2 position;\n"
"void main() { gl_Position = vec4(position, 0.0, 1.0); }\n";
simple_vertex_id = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(simple_vertex_id, 1, &simpleVertexSource, NULL);
glCompileShader(simple_vertex_id);
check_shader(simple_vertex_id, simpleVertexSource);
simpleProgramId = glCreateProgram();
glAttachShader(simpleProgramId, simple_vertex_id);
glBindAttribLocation(simpleProgramId, 0, "position");
glLinkProgram(simpleProgramId);
check_program(simpleProgramId, "simple");
// color
const char *colorFragmentSource =
"uniform vec4 color;\n"
//"out vec4 colorOut;\n"
"void main() { gl_FragColor = color; }\n";
color_fragment_id = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(color_fragment_id, 1, &colorFragmentSource, NULL);
glCompileShader(color_fragment_id);
check_shader(color_fragment_id, colorFragmentSource);
colorProgramId = glCreateProgram();
glAttachShader(colorProgramId, simple_vertex_id);
glAttachShader(colorProgramId, color_fragment_id);
glBindAttribLocation(colorProgramId, 0, "position");
//glBindFragDataLocation(color_program_id, 0, "colorOut");
glLinkProgram(colorProgramId);
check_program(colorProgramId, "color");
colorUniform = glGetUniformLocation(colorProgramId, "color");
}
Shaders::~Shaders() {
glUseProgram(0);
glDeleteProgram(colorProgramId);
glDeleteProgram(simpleProgramId);
glDeleteShader(color_fragment_id);
glDeleteShader(simple_vertex_id);
}
void Shaders::check_shader(GLuint id, const char *src) {
GLint compileStatus = 0;
glGetShaderiv(id, GL_COMPILE_STATUS, &compileStatus);
if (!compileStatus) {
GLint infoLogLength = 0;
glGetShaderiv(id, GL_INFO_LOG_LENGTH, &infoLogLength);
std::string infoLog;
infoLog.resize(infoLogLength);
glGetShaderInfoLog(id, infoLog.size(), &infoLogLength, &infoLog[0]);
infoLog.resize(infoLogLength);
cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl
<< "cannot compile shader:" << endl
<< "~~~~~~source~~~~~~~~~~~~~~~" << endl
<< src << endl
<< "~~~~~~log~~~~~~~~~~~~~~~~~~" << endl
<< infoLog << endl
<< "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl;
}
}
void Shaders::check_program(GLuint id, const char *name) {
GLint linkStatus = 0;
glGetProgramiv(id, GL_LINK_STATUS, &linkStatus);
if (!linkStatus) {
GLint infoLogLength = 0;
glGetProgramiv(id, GL_INFO_LOG_LENGTH, &infoLogLength);
std::string infoLog;
infoLog.resize(infoLogLength);
glGetProgramInfoLog(id, infoLog.size(), &infoLogLength, &infoLog[0]);
infoLog.resize(infoLogLength);
cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl
<< "cannot link program " << name << ":" << endl
<< "~~~~~~name~~~~~~~~~~~~~~~~~" << endl
<< name << endl
<< "~~~~~~log~~~~~~~~~~~~~~~~~~" << endl
<< infoLog << endl
<< "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl;
}
glValidateProgram(id);
GLint validateStatus = 0;
glGetProgramiv(id, GL_VALIDATE_STATUS, &validateStatus);
if (!validateStatus) {
GLint infoLogLength = 0;
glGetProgramiv(id, GL_INFO_LOG_LENGTH, &infoLogLength);
std::string infoLog;
infoLog.resize(infoLogLength);
glGetProgramInfoLog(id, infoLog.size(), &infoLogLength, &infoLog[0]);
infoLog.resize(infoLogLength);
cout << "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl
<< "program not validated " << name << ":" << endl
<< "~~~~~~name~~~~~~~~~~~~~~~~~" << endl
<< name << endl
<< "~~~~~~log~~~~~~~~~~~~~~~~~~" << endl
<< infoLog << endl
<< "~~~~~~~~~~~~~~~~~~~~~~~~~~~" << endl;
}
}
void Shaders::simple() {
glUseProgram(simpleProgramId);
}
void Shaders::color(const Color &c) {
glUseProgram(colorProgramId);
glUniform4fv(colorUniform, 1, c.channels);
}