src/graphics/shader.cpp

   1 #include "BlockLighting.hpp"
   2 #include "DirectionalLighting.hpp"
   3 #include "Program.hpp"
   4 #include "Shader.hpp"
   5
   6 #include "../app/init.hpp"
   7
   8 #include <algorithm>
   9 #include <iostream>
  10 #include <memory>
  11 #include <ostream>
  12 #include <stdexcept>
  13 #include <string>
  14
  15
  16 namespace {
  17
  18 void gl_error(std::string msg) {
  19         const GLubyte *errBegin = gluErrorString(glGetError());
  20         if (errBegin && *errBegin != '\0') {
  21                 const GLubyte *errEnd = errBegin;
  22                 while (*errEnd != '\0') {
  23                         ++errEnd;
  24                 }
  25                 msg += ": ";
  26                 msg.append(errBegin, errEnd);
  27         }
  28         throw std::runtime_error(msg);
  29 }
  30
  31 }
  32
  33 namespace blank {
  34
  35 Shader::Shader(GLenum type)
  36 : handle(glCreateShader(type)) {
  37         if (handle == 0) {
  38                 gl_error("glCreateShader");
  39         }
  40 }
  41
  42 Shader::~Shader() {
  43         if (handle != 0) {
  44                 glDeleteShader(handle);
  45         }
  46 }
  47
  48 Shader::Shader(Shader &&other) noexcept
  49 : handle(other.handle) {
  50         other.handle = 0;
  51 }
  52
  53 Shader &Shader::operator =(Shader &&other) noexcept {
  54         std::swap(handle, other.handle);
  55         return *this;
  56 }
  57
  58
  59 void Shader::Source(const GLchar *src) noexcept {
  60         const GLchar* src_arr[] = { src };
  61         glShaderSource(handle, 1, src_arr, nullptr);
  62 }
  63
  64 void Shader::Compile() noexcept {
  65         glCompileShader(handle);
  66 }
  67
  68 bool Shader::Compiled() const noexcept {
  69         GLint compiled = GL_FALSE;
  70         glGetShaderiv(handle, GL_COMPILE_STATUS, &compiled);
  71         return compiled == GL_TRUE;
  72 }
  73
  74 void Shader::Log(std::ostream &out) const {
  75         int log_len = 0, max_len = 0;
  76         glGetShaderiv(handle, GL_INFO_LOG_LENGTH, &max_len);
  77         std::unique_ptr<char[]> log(new char[max_len]);
  78         glGetShaderInfoLog(handle, max_len, &log_len, log.get());
  79         out.write(log.get(), log_len);
  80 }
  81
  82
  83 void Shader::AttachToProgram(GLuint id) const noexcept {
  84         glAttachShader(id, handle);
  85 }
  86
  87
  88 Program::Program()
  89 : handle(glCreateProgram()) {
  90         if (handle == 0) {
  91                 gl_error("glCreateProgram");
  92         }
  93 }
  94
  95 Program::~Program() {
  96         if (handle != 0) {
  97                 glDeleteProgram(handle);
  98         }
  99 }
 100
 101
 102 const Shader &Program::LoadShader(GLenum type, const GLchar *src) {
 103         shaders.emplace_back(type);
 104         Shader &shader = shaders.back();
 105         shader.Source(src);
 106         shader.Compile();
 107         if (!shader.Compiled()) {
 108                 shader.Log(std::cerr);
 109                 throw std::runtime_error("compile shader");
 110         }
 111         Attach(shader);
 112         return shader;
 113 }
 114
 115 void Program::Attach(Shader &shader) noexcept {
 116         shader.AttachToProgram(handle);
 117 }
 118
 119 void Program::Link() noexcept {
 120         glLinkProgram(handle);
 121 }
 122
 123 bool Program::Linked() const noexcept {
 124         GLint linked = GL_FALSE;
 125         glGetProgramiv(handle, GL_LINK_STATUS, &linked);
 126         return linked == GL_TRUE;
 127 }
 128
 129 void Program::Log(std::ostream &out) const {
 130         int log_len = 0, max_len = 0;
 131         glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &max_len);
 132         std::unique_ptr<char[]> log(new char[max_len]);
 133         glGetProgramInfoLog(handle, max_len, &log_len, log.get());
 134         out.write(log.get(), log_len);
 135 }
 136
 137
 138 GLint Program::AttributeLocation(const GLchar *name) const noexcept {
 139         return glGetAttribLocation(handle, name);
 140 }
 141
 142 GLint Program::UniformLocation(const GLchar *name) const noexcept {
 143         return glGetUniformLocation(handle, name);
 144 }
 145
 146
 147 DirectionalLighting::DirectionalLighting()
 148 : program()
 149 , light_direction(1.0f, 3.0f, 2.0f)
 150 , light_color(0.9f, 0.9f, 0.9f)
 151 , vp(1.0f)
 152 , m_handle(0)
 153 , mv_handle(0)
 154 , mvp_handle(0)
 155 , light_direction_handle(0)
 156 , light_color_handle(0)
 157 , fog_density_handle(0) {
 158         program.LoadShader(
 159                 GL_VERTEX_SHADER,
 160                 "#version 330 core\n"
 161                 "layout(location = 0) in vec3 vtx_position;\n"
 162                 "layout(location = 1) in vec3 vtx_color;\n"
 163                 "layout(location = 2) in vec3 vtx_normal;\n"
 164                 "uniform mat4 M;\n"
 165                 "uniform mat4 MV;\n"
 166                 "uniform mat4 MVP;\n"
 167                 "out vec3 frag_color;\n"
 168                 "out vec3 vtx_viewspace;\n"
 169                 "out vec3 normal;\n"
 170                 "void main() {\n"
 171                         "gl_Position = MVP * vec4(vtx_position, 1);\n"
 172                         "vtx_viewspace = (MV * vec4(vtx_position, 1)).xyz;\n"
 173                         "normal = (M * vec4(vtx_normal, 0)).xyz;\n"
 174                         "frag_color = vtx_color;\n"
 175                 "}\n"
 176         );
 177         program.LoadShader(
 178                 GL_FRAGMENT_SHADER,
 179                 "#version 330 core\n"
 180                 "in vec3 frag_color;\n"
 181                 "in vec3 vtx_viewspace;\n"
 182                 "in vec3 normal;\n"
 183                 "uniform vec3 light_direction;\n"
 184                 "uniform vec3 light_color;\n"
 185                 "uniform float fog_density;\n"
 186                 "out vec3 color;\n"
 187                 "void main() {\n"
 188                         "vec3 ambient = vec3(0.1, 0.1, 0.1) * frag_color;\n"
 189                         // this should be the same as the clear color, otherwise looks really weird
 190                         "vec3 fog_color = vec3(0, 0, 0);\n"
 191                         "float e = 2.718281828;\n"
 192                         "vec3 n = normalize(normal);\n"
 193                         "vec3 l = normalize(light_direction);\n"
 194                         "float cos_theta = clamp(dot(n, l), 0, 1);\n"
 195                         "vec3 reflect_color = ambient + frag_color * light_color * cos_theta;\n"
 196                         "float value = pow(e, -pow(fog_density * length(vtx_viewspace), 5));"
 197                         "color = mix(fog_color, reflect_color, value);\n"
 198                 "}\n"
 199         );
 200         program.Link();
 201         if (!program.Linked()) {
 202                 program.Log(std::cerr);
 203                 throw std::runtime_error("link program");
 204         }
 205
 206         m_handle = program.UniformLocation("M");
 207         mv_handle = program.UniformLocation("MV");
 208         mvp_handle = program.UniformLocation("MVP");
 209         light_direction_handle = program.UniformLocation("light_direction");
 210         light_color_handle = program.UniformLocation("light_color");
 211         fog_density_handle = program.UniformLocation("fog_density");
 212 }
 213
 214
 215 void DirectionalLighting::Activate() noexcept {
 216         GLContext::EnableDepthTest();
 217         GLContext::EnableBackfaceCulling();
 218         program.Use();
 219
 220         glUniform3f(light_direction_handle, light_direction.x, light_direction.y, light_direction.z);
 221         glUniform3f(light_color_handle, light_color.x, light_color.y, light_color.z);
 222 }
 223
 224 void DirectionalLighting::SetM(const glm::mat4 &m) noexcept {
 225         glm::mat4 mv(view * m);
 226         glm::mat4 mvp(vp * m);
 227         glUniformMatrix4fv(m_handle, 1, GL_FALSE, &m[0][0]);
 228         glUniformMatrix4fv(mv_handle, 1, GL_FALSE, &mv[0][0]);
 229         glUniformMatrix4fv(mvp_handle, 1, GL_FALSE, &mvp[0][0]);
 230 }
 231
 232 void DirectionalLighting::SetLightDirection(const glm::vec3 &dir) noexcept {
 233         light_direction = -dir;
 234         glUniform3f(light_direction_handle, light_direction.x, light_direction.y, light_direction.z);
 235 }
 236
 237 void DirectionalLighting::SetFogDensity(float f) noexcept {
 238         fog_density = f;
 239         glUniform1f(fog_density_handle, fog_density);
 240 }
 241
 242 void DirectionalLighting::SetProjection(const glm::mat4 &p) noexcept {
 243         projection = p;
 244         vp = p * view;
 245 }
 246
 247 void DirectionalLighting::SetView(const glm::mat4 &v) noexcept {
 248         view = v;
 249         vp = projection * v;
 250 }
 251
 252 void DirectionalLighting::SetVP(const glm::mat4 &v, const glm::mat4 &p) noexcept {
 253         projection = p;
 254         view = v;
 255         vp = p * v;
 256 }
 257
 258 void DirectionalLighting::SetMVP(const glm::mat4 &m, const glm::mat4 &v, const glm::mat4 &p) noexcept {
 259         SetVP(v, p);
 260         SetM(m);
 261 }
 262
 263
 264 BlockLighting::BlockLighting()
 265 : program()
 266 , vp(1.0f)
 267 , mv_handle(0)
 268 , mvp_handle(0)
 269 , fog_density_handle(0) {
 270         program.LoadShader(
 271                 GL_VERTEX_SHADER,
 272                 "#version 330 core\n"
 273                 "layout(location = 0) in vec3 vtx_position;\n"
 274                 "layout(location = 1) in vec3 vtx_color;\n"
 275                 "layout(location = 2) in float vtx_light;\n"
 276                 "uniform mat4 MV;\n"
 277                 "uniform mat4 MVP;\n"
 278                 "out vec3 frag_color;\n"
 279                 "out vec3 vtx_viewspace;\n"
 280                 "out float frag_light;\n"
 281                 "void main() {\n"
 282                         "gl_Position = MVP * vec4(vtx_position, 1);\n"
 283                         "frag_color = vtx_color;\n"
 284                         "vtx_viewspace = (MV * vec4(vtx_position, 1)).xyz;\n"
 285                         "frag_light = vtx_light;\n"
 286                 "}\n"
 287         );
 288         program.LoadShader(
 289                 GL_FRAGMENT_SHADER,
 290                 "#version 330 core\n"
 291                 "in vec3 frag_color;\n"
 292                 "in vec3 vtx_viewspace;\n"
 293                 "in float frag_light;\n"
 294                 "uniform float fog_density;\n"
 295                 "out vec3 color;\n"
 296                 "void main() {\n"
 297                         "vec3 ambient = vec3(0.1, 0.1, 0.1) * frag_color;\n"
 298                         "float light_power = clamp(pow(0.8, 15 - frag_light), 0, 1);\n"
 299                         "vec3 fog_color = vec3(0, 0, 0);\n"
 300                         "float e = 2.718281828;\n"
 301                         //"vec3 reflect_color = ambient + frag_color * light_power;\n"
 302                         "vec3 reflect_color = frag_color * light_power;\n"
 303                         "float value = pow(e, -pow(fog_density * length(vtx_viewspace), 5));"
 304                         "color = mix(fog_color, reflect_color, value);\n"
 305                 "}\n"
 306         );
 307         program.Link();
 308         if (!program.Linked()) {
 309                 program.Log(std::cerr);
 310                 throw std::runtime_error("link program");
 311         }
 312
 313         mv_handle = program.UniformLocation("MV");
 314         mvp_handle = program.UniformLocation("MVP");
 315         fog_density_handle = program.UniformLocation("fog_density");
 316 }
 317
 318
 319 void BlockLighting::Activate() noexcept {
 320         GLContext::EnableDepthTest();
 321         GLContext::EnableBackfaceCulling();
 322         program.Use();
 323 }
 324
 325 void BlockLighting::SetM(const glm::mat4 &m) noexcept {
 326         glm::mat4 mv(view * m);
 327         glm::mat4 mvp(vp * m);
 328         glUniformMatrix4fv(mv_handle, 1, GL_FALSE, &mv[0][0]);
 329         glUniformMatrix4fv(mvp_handle, 1, GL_FALSE, &mvp[0][0]);
 330 }
 331
 332 void BlockLighting::SetFogDensity(float f) noexcept {
 333         fog_density = f;
 334         glUniform1f(fog_density_handle, fog_density);
 335 }
 336
 337 void BlockLighting::SetProjection(const glm::mat4 &p) noexcept {
 338         projection = p;
 339         vp = p * view;
 340 }
 341
 342 void BlockLighting::SetView(const glm::mat4 &v) noexcept {
 343         view = v;
 344         vp = projection * v;
 345 }
 346
 347 void BlockLighting::SetVP(const glm::mat4 &v, const glm::mat4 &p) noexcept {
 348         projection = p;
 349         view = v;
 350         vp = p * v;
 351 }
 352
 353 void BlockLighting::SetMVP(const glm::mat4 &m, const glm::mat4 &v, const glm::mat4 &p) noexcept {
 354         SetVP(v, p);
 355         SetM(m);
 356 }
 357
 358 }