aboutsummaryrefslogtreecommitdiff
path: root/src/opengl/shaders.cpp
blob: 34d4e8f75fa41db91cbb4b5a5607a079460f30f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
#include "shaders.hpp"

GLuint CompileShader(std::string shader_name){
  std::ifstream shader_file;
  shader_file.open(std::string(SHADERS_RESOURCES) + "/" + shader_name);
  if(!shader_file.is_open()) {
     std::cout << "Failed to open: " << shader_name << std::endl;
     exit(EXIT_FAILURE);
  }

  std::string line;
  char type='\0';
  std::stringstream ss[2];
  while(getline(shader_file, line)) {
    if(line.find("- Vertex Shader -") != std::string::npos){
    	type='v';
    } else if(line.find("- Fragment Shader -") != std::string::npos){
    	type='f';
    }

    if(type=='v')
    	ss[0] << line << std::endl;
    else if(type=='f')
    	ss[1] << line << std::endl;
   }

  // Create ids
  GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
  GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);

  // Compile vertex shader
  std::string vsrc=ss[0].str();
  char const * vsrc_c = vsrc.c_str();
  glShaderSource(VertexShaderID, 1, &vsrc_c, NULL);
  glCompileShader(VertexShaderID);

  // Compile fragment shader
  std::string fsrc=ss[1].str();
  char const * fsrc_c = fsrc.c_str();
  glShaderSource(FragmentShaderID, 1, &fsrc_c, NULL);
  glCompileShader(FragmentShaderID);

  // Link programs
  GLuint ProgramID = glCreateProgram();
  glAttachShader(ProgramID, VertexShaderID);
  glAttachShader(ProgramID, FragmentShaderID);
  glLinkProgram(ProgramID);

  // Cleaning
  glDetachShader(ProgramID, VertexShaderID);
  glDetachShader(ProgramID, FragmentShaderID);
  glDeleteShader(VertexShaderID);
  glDeleteShader(FragmentShaderID);

  return ProgramID;
}


GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path){

	// Create the shaders
	GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
	GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);

	// Read the Vertex Shader code from the file
	std::string VertexShaderCode;
	std::ifstream VertexShaderStream(vertex_file_path, std::ios::in);
	if(VertexShaderStream.is_open()){
		std::stringstream sstr;
		sstr << VertexShaderStream.rdbuf();
		VertexShaderCode = sstr.str();
		VertexShaderStream.close();
	}else{
		printf("Impossible to open %s. Are you in the right directory ? Don't forget to read the FAQ !\n", vertex_file_path);
		getchar();
		return 0;
	}

	// Read the Fragment Shader code from the file
	std::string FragmentShaderCode;
	std::ifstream FragmentShaderStream(fragment_file_path, std::ios::in);
	if(FragmentShaderStream.is_open()){
		std::stringstream sstr;
		sstr << FragmentShaderStream.rdbuf();
		FragmentShaderCode = sstr.str();
		FragmentShaderStream.close();
	}
    
	GLint Result = GL_FALSE;
	int InfoLogLength;


	// Compile Vertex Shader
	printf("Compiling shader : %s\n", vertex_file_path);
	char const * VertexSourcePointer = VertexShaderCode.c_str();
	glShaderSource(VertexShaderID, 1, &VertexSourcePointer , NULL);
	glCompileShader(VertexShaderID);

	// Check Vertex Shader
	glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &Result);
	glGetShaderiv(VertexShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
	if ( InfoLogLength > 0 ){
		std::vector<char> VertexShaderErrorMessage(InfoLogLength+1);
		glGetShaderInfoLog(VertexShaderID, InfoLogLength, NULL, &VertexShaderErrorMessage[0]);
		printf("%s\n", &VertexShaderErrorMessage[0]);
	}



	// Compile Fragment Shader
	printf("Compiling shader : %s\n", fragment_file_path);
	char const * FragmentSourcePointer = FragmentShaderCode.c_str();
	glShaderSource(FragmentShaderID, 1, &FragmentSourcePointer , NULL);
	glCompileShader(FragmentShaderID);

	// Check Fragment Shader
	glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &Result);
	glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &InfoLogLength);
	if ( InfoLogLength > 0 ){
		std::vector<char> FragmentShaderErrorMessage(InfoLogLength+1);
		glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &FragmentShaderErrorMessage[0]);
		printf("%s\n", &FragmentShaderErrorMessage[0]);
	}

	// Link the program
	printf("Linking program\n");
	GLuint ProgramID = glCreateProgram();
	glAttachShader(ProgramID, VertexShaderID);
	glAttachShader(ProgramID, FragmentShaderID);
	glLinkProgram(ProgramID);

	// Check the program
	glGetProgramiv(ProgramID, GL_LINK_STATUS, &Result);
	glGetProgramiv(ProgramID, GL_INFO_LOG_LENGTH, &InfoLogLength);
	if ( InfoLogLength > 0 ){
		std::vector<char> ProgramErrorMessage(InfoLogLength+1);
		glGetProgramInfoLog(ProgramID, InfoLogLength, NULL, &ProgramErrorMessage[0]);
		printf("%s\n", &ProgramErrorMessage[0]);
	}

	
	glDetachShader(ProgramID, VertexShaderID);
	glDetachShader(ProgramID, FragmentShaderID);
	
	glDeleteShader(VertexShaderID);
	glDeleteShader(FragmentShaderID);

	return ProgramID;
}