src/shader.cpp

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