aboutsummaryrefslogtreecommitdiffstats
path: root/dev/MinGfx/src/shader_program.cc
blob: 389b630972a10d531737caa848e163ffa9f4c948 (plain) (blame)
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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
/*
 Copyright (c) 2017,2018 Regents of the University of Minnesota.
 All Rights Reserved.
 See corresponding header file for details.
 */

#include "shader_program.h"

#include "opengl_headers.h"

#include <vector>
#include <fstream>


namespace mingfx {


ShaderProgram::ShaderProgram() : vertexShader_(0), fragmentShader_(0), program_(0) {
}

ShaderProgram::~ShaderProgram() {
}
    
bool ShaderProgram::initialized() {
    return (program_ != 0);
}

bool ShaderProgram::AddVertexShaderFromSource(const std::string &vertexSource) {
    // https://www.khronos.org/opengl/wiki/Shader_Compilation
    
    // Create an empty vertex shader handle
    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_);
        
        std::cerr << "ShaderProgram: Error compiling vertex shader program: " << std::endl;
        std::cerr << &infoLog[0] << std::endl;
        std::cerr << vertexSource << std::endl;
        return false;
    }
    return true;
}
    
bool ShaderProgram::AddVertexShaderFromFile(const std::string &file) {
    std::cout << "Loading vertex shader from file: " << file << std::endl;
    std::string source;
    std::string line;
    std::ifstream myfile (file);
    if (myfile.is_open()) {
        while (std::getline(myfile, line)) {
            source += line + "\n";
        }
        myfile.close();
        return AddVertexShaderFromSource(source);
    }
    else {
        std::cerr << "ShaderProgram: Cannot open file " << file << std::endl;
        return false;
    }
}

    
    
bool ShaderProgram::AddFragmentShaderFromSource(const std::string &fragmentSource) {
    // https://www.khronos.org/opengl/wiki/Shader_Compilation
    
    // Create an empty fragment shader handle
    fragmentShader_ = glCreateShader(GL_FRAGMENT_SHADER);
    
    // Send the fragment shader source code to GL
    // Note that std::string's .c_str is NULL character terminated.
    const GLchar *source = (const GLchar *)fragmentSource.c_str();
    glShaderSource(fragmentShader_, 1, &source, 0);
    
    // Compile the fragment shader
    glCompileShader(fragmentShader_);
    
    GLint isCompiled = 0;
    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_);
        
        std::cerr << "ShaderProgram: Error compiling fragment shader program: " << std::endl;
        std::cerr << &infoLog[0] << std::endl;
        std::cerr << fragmentSource << std::endl;
        return false;
    }
    return true;
}


bool ShaderProgram::AddFragmentShaderFromFile(const std::string &file) {
    std::cout << "Loading fragment shader from file: " << file << std::endl;
    std::string source;
    std::string line;
    std::ifstream myfile (file);
    if (myfile.is_open()) {
        while (std::getline(myfile, line)) {
            source += line + "\n";
        }
        myfile.close();
        return AddFragmentShaderFromSource(source);
    }
    else {
        std::cerr << "ShaderProgram: Cannot open file " << file << std::endl;
        return false;
    }
}

    
bool ShaderProgram::LinkProgram() {
    if (!vertexShader_) {
        std::cerr << "ShaderProgram: Error linking program.  A vertex shader must be added and successfully compiled before the program can be linked." << std::endl;
        return false;
    }
    if (!fragmentShader_) {
        std::cerr << "ShaderProgram: Error linking program.  A fragment shader must be added and successfully compiled before the program can be linked." << std::endl;
        return false;
    }
    
    // Vertex and fragment shaders are successfully compiled.
    // Now time to link them together into a program.
    // Get a program object.
    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_);
        
        std::cerr << "ShaderProgram: Error linking program: " << std::endl;
        std::cerr << &infoLog[0] << std::endl;
        return false;
    }
    
    // Always detach shaders after a successful link.
    glDetachShader(program_, vertexShader_);
    glDetachShader(program_, fragmentShader_);
    
    return true;
}
    

void ShaderProgram::UseProgram() {
    if (!initialized()) {
        std::cerr << "ShaderProgram: Warning cannot UseProgram() until it shaders have been added and linked.  Calling LinkProgram() for you now." << std::endl;
        LinkProgram();
    }
    glUseProgram(program_);
}

    
void ShaderProgram::StopProgram() {
    glUseProgram(0);
}
    
    
// MinGfx math types
void ShaderProgram::SetUniform(const std::string &name, const Point2 &p) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform2f(loc, p[0], p[1]);
}

void ShaderProgram::SetUniform(const std::string &name, const Vector2 &v) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform2f(loc, v[0], v[1]);
}

void ShaderProgram::SetUniform(const std::string &name, const Point3 &p) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform3f(loc, p[0], p[1], p[2]);
}

void ShaderProgram::SetUniform(const std::string &name, const Vector3 &v) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform3f(loc, v[0], v[1], v[2]);
}

void ShaderProgram::SetUniform(const std::string &name, const Matrix4 &m) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniformMatrix4fv(loc, 1, GL_FALSE, m.value_ptr());
}

void ShaderProgram::SetUniform(const std::string &name, const Color &c) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform4f(loc, c[0], c[1], c[2], c[3]);
}
    

// built-in types
void ShaderProgram::SetUniform(const std::string &name, int i) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1i(loc, i);
}

void ShaderProgram::SetUniform(const std::string &name, unsigned int ui) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1ui(loc, ui);
}

void ShaderProgram::SetUniform(const std::string &name, float f) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1f(loc, f);
}



// built-in types - arrays
void ShaderProgram::SetUniformArray1(const std::string &name, int *i, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1iv(loc, count, i);
}

void ShaderProgram::SetUniformArray1(const std::string &name, unsigned int *ui, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1uiv(loc, count, ui);
}

void ShaderProgram::SetUniformArray1(const std::string &name, float *f, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1fv(loc, count, f);
}


void ShaderProgram::SetUniformArray2(const std::string &name, int *i, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform2iv(loc, count, i);
}

void ShaderProgram::SetUniformArray2(const std::string &name, unsigned int *ui, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform2uiv(loc, count, ui);
}

void ShaderProgram::SetUniformArray2(const std::string &name, float *f, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform2fv(loc, count, f);
}


void ShaderProgram::SetUniformArray3(const std::string &name, int *i, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform3iv(loc, count, i);
}

void ShaderProgram::SetUniformArray3(const std::string &name, unsigned int *ui, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform3uiv(loc, count, ui);
}

void ShaderProgram::SetUniformArray3(const std::string &name, float *f, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform3fv(loc, count, f);
}


void ShaderProgram::SetUniformArray4(const std::string &name, int *i, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform4iv(loc, count, i);
}

void ShaderProgram::SetUniformArray4(const std::string &name, unsigned int *ui, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform4uiv(loc, count, ui);
}

void ShaderProgram::SetUniformArray4(const std::string &name, float *f, int count) {
    UseProgram();
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform4fv(loc, count, f);
}



void ShaderProgram::BindTexture(const std::string &name, const Texture2D &tex) {
    UseProgram();

    int texUnit = 0;
    
    std::map<std::string,int>::const_iterator it = texBindings_.find(name);
    if (it != texBindings_.end()) {
        // Found: This sampler was already bound to a tex unit, so use the same one
        texUnit = texBindings_[name];
    }
    else {
        // Not found: This sampler was not already bound to a tex unit, so loop through the
        // past/current bindings and pick the next available texUnit
        std::map<std::string,int>::const_iterator it2;
        for (it2 = texBindings_.begin(); it2 != texBindings_.end(); ++it2) {
            if (texUnit <= it2->second) {
                texUnit = it2->second + 1;
            }
        }
        // save it for future reference
        texBindings_[name] = texUnit;
    }
    
    // associate the named shader program sampler variable with the selected texture unit
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1i(loc, texUnit);
    // bind the opengl texture handle to the same texture unit
    glActiveTexture(GL_TEXTURE0 + texUnit);
    glBindTexture(GL_TEXTURE_2D, tex.opengl_id());
}

void ShaderProgram::BindTexture(const std::string &name, const Texture2D &tex, int texUnit) {
    UseProgram();

    texBindings_[name] = texUnit;
    
    // associate the named shader program sampler variable with the selected texture unit
    GLint loc = glGetUniformLocation(program_, name.c_str());
    glUniform1i(loc, texUnit);
    // bind the opengl texture handle to the same texture unit
    glActiveTexture(GL_TEXTURE0 + texUnit);
    glBindTexture(GL_TEXTURE_2D, tex.opengl_id());
}


    
} // end namespace