src/graphics/shader.c

   1 /************************************************************************
   2 * shader.c
   3 * voxelands - 3d voxel world sandbox game
   4 * Copyright (C) Lisa 'darkrose' Milne 2016 <lisa@ltmnet.com>
   5 *
   6 * This program is free software: you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation, either version 3 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14 * See the GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program.  If not, see <http://www.gnu.org/licenses/>
  18 ************************************************************************/
  19
  20 #include "common.h"
  21 #include "graphics.h"
  22 #include "file.h"
  23 #include "list.h"
  24
  25 #include <string.h>
  26
  27 static shader_t *shaders = NULL;
  28 static shader_t *active = NULL;
  29
  30 static GLuint shader_load(file_t *f, GLenum type)
  31 {
  32         GLint i;
  33         GLuint s = 0;
  34
  35         if (!f)
  36                 return s;
  37
  38         s = glCreateShader(type);
  39         glShaderSource(s, 1, (const GLchar**)&f->data,NULL);
  40         glCompileShader(s);
  41         glGetShaderiv(s,GL_COMPILE_STATUS,&i);
  42         if (i == GL_FALSE) {
  43                 char buff[512];
  44                 glGetShaderInfoLog(s,512,&i,buff);
  45                 vlprintf("Shader %s failed to compile: %s",f->name,buff);
  46                 glDeleteShader(s);
  47                 s = 0;
  48         }
  49
  50         return s;
  51 }
  52
  53 shader_t *shader_create(char* name)
  54 {
  55         char buff[512];
  56         file_t *vert;
  57         file_t *geom;
  58         file_t *frag;
  59         shader_t *s;
  60         GLint i;
  61
  62         if (snprintf(buff,512,"%s_vertex.glsl",name) < 512)
  63                 vert = file_load("shader",buff);
  64         if (snprintf(buff,512,"%s_geometry.glsl",name) < 512)
  65                 geom = file_load("shader",buff);
  66         if (snprintf(buff,512,"%s_fragment.glsl",name) < 512)
  67                 frag = file_load("shader",buff);
  68
  69         if (!vert && !geom && !frag)
  70                 return NULL;
  71
  72         s = malloc(sizeof(shader_t));
  73         if (!s) {
  74                 if (vert)
  75                         file_free(vert);
  76                 if (geom)
  77                         file_free(geom);
  78                 if (frag)
  79                         file_free(frag);
  80                 return NULL;
  81         }
  82
  83         strncpy(s->name,name,256);
  84         s->active = 0;
  85         s->program = 0;
  86         s->vert = 0;
  87         s->geom = 0;
  88         s->frag = 0;
  89
  90         if (vert)
  91                 s->vert = shader_load(vert,GL_VERTEX_SHADER);
  92         if (geom)
  93                 s->geom = shader_load(geom,GL_GEOMETRY_SHADER);
  94         if (frag)
  95                 s->frag = shader_load(frag,GL_FRAGMENT_SHADER);
  96
  97         if (!s->vert && !s->geom && !s->frag) {
  98                 if (vert)
  99                         file_free(vert);
 100                 if (geom)
 101                         file_free(geom);
 102                 if (frag)
 103                         file_free(frag);
 104                 free(s);
 105                 return NULL;
 106         }
 107
 108         s->program = glCreateProgram();
 109         if (s->vert)
 110                 glAttachShader(s->program,s->vert);
 111         if (s->geom)
 112                 glAttachShader(s->program,s->geom);
 113         if (s->frag)
 114                 glAttachShader(s->program,s->frag);
 115         glLinkProgram(s->program);
 116         glGetProgramiv(s->program, GL_LINK_STATUS, &i);
 117         if (i == GL_FALSE) {
 118                 glGetProgramInfoLog(s->program, 512, &i, buff);
 119                 vlprintf("Shader failed to link: %s",buff);
 120         }
 121
 122         glValidateProgram(s->program);
 123
 124         if (vert)
 125                 file_free(vert);
 126         if (geom)
 127                 file_free(geom);
 128         if (frag)
 129                 file_free(frag);
 130
 131         shaders = list_push(&shaders,s);
 132
 133         return s;
 134 }
 135
 136 /* free a shader */
 137 void shader_free(shader_t *s)
 138 {
 139         if (!s)
 140                 return;
 141
 142         if (s->active)
 143                 shader_disable(s);
 144
 145         glDetachShader(s->program,s->vert);
 146         glDetachShader(s->program,s->frag);
 147         glDeleteShader(s->vert);
 148         glDeleteShader(s->frag);
 149         glDeleteProgram(s->program);
 150
 151         free(s);
 152 }
 153
 154 /* bind an attribute to a shader */
 155 int shader_attribute(shader_t *s, int att, char* name)
 156 {
 157         if (!s)
 158                 return 1;
 159
 160         glBindAttribLocation(s->program,att,name);
 161         glLinkProgram(s->program);
 162         glValidateProgram(s->program);
 163
 164         return 0;
 165 }
 166
 167 /* set a shader uniform value */
 168 int shader_uniform_int(shader_t *s, char* name, int value)
 169 {
 170         GLuint var;
 171         if (!s)
 172                 s = active;
 173         if (!s)
 174                 return 1;
 175
 176         var = glGetUniformLocation(s->program,name);
 177         glUniform1i(var,value);
 178
 179         return 0;
 180 }
 181
 182 /* set a shader uniform value */
 183 int shader_uniform_float(shader_t *s, char* name, float value)
 184 {
 185         GLuint var;
 186         if (!s)
 187                 s = active;
 188         if (!s)
 189                 return 1;
 190
 191         var = glGetUniformLocation(s->program,name);
 192         glUniform1f(var,value);
 193
 194         return 0;
 195 }
 196
 197 /* set a shader uniform value */
 198 int shader_uniform_v2(shader_t *s, char* name, v2_t *value)
 199 {
 200         GLuint var;
 201         if (!s)
 202                 s = active;
 203         if (!s)
 204                 return 1;
 205
 206         var = glGetUniformLocation(s->program,name);
 207         glUniform2f(var,value->x,value->y);
 208
 209         return 0;
 210 }
 211
 212 /* set a shader uniform value */
 213 int shader_uniform_v3(shader_t *s, char* name, v3_t *value)
 214 {
 215         GLuint var;
 216         if (!s)
 217                 s = active;
 218         if (!s)
 219                 return 1;
 220
 221         var = glGetUniformLocation(s->program,name);
 222         glUniform3f(var,value->x,value->y,value->z);
 223
 224         return 0;
 225 }
 226
 227 /* set a shader uniform value */
 228 int shader_uniform_matrix(shader_t *s, char* name, matrix_t *value)
 229 {
 230         GLuint var;
 231         if (!s)
 232                 s = active;
 233         if (!s)
 234                 return 1;
 235
 236         var = glGetUniformLocation(s->program,name);
 237         glUniformMatrix4fv(var,1,GL_FALSE,value->data);
 238
 239         return 0;
 240 }
 241
 242 /* use a shader */
 243 int shader_enable(shader_t *s)
 244 {
 245         if (!s || s->active)
 246                 return 1;
 247
 248         if (active)
 249                 shader_disable(active);
 250
 251         glUseProgram(s->program);
 252         s->active = 1;
 253
 254         active = s;
 255
 256         return 0;
 257 }
 258
 259 /* stop using a shader */
 260 int shader_disable(shader_t *s)
 261 {
 262         if (!s || !s->active)
 263                 return 1;
 264
 265         active = NULL;
 266
 267         glUseProgram(0);
 268         s->active = 0;
 269
 270         return 0;
 271 }