src/graphics/material.c

   1 /************************************************************************
   2 * material.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 "list.h"
  23
  24 #include <string.h>
  25
  26 static struct {
  27         material_t *materials;
  28         int ids;
  29         GLuint current_texture;
  30         uint8_t culling;
  31         uint8_t blended;
  32         GLenum blend_mode;
  33 } mat_data ={
  34         NULL,
  35         0,
  36         0,
  37         0,
  38         0,
  39         GL_ZERO
  40 };
  41
  42 /* create a new blank material */
  43 material_t *mat_create()
  44 {
  45         material_t *mat = malloc(sizeof(material_t));
  46         mat->id = mat_data.ids++;
  47         mat->name[0] = 0;
  48         mat->options = MATOPT_BFCULL;
  49         mat->tex = NULL;
  50         mat->next = NULL;
  51         mat->shininess = 1.0;
  52         mat->reflectivity = 0.0;
  53         mat->bumpiness = 0.0;
  54
  55         mat_data.materials = list_push(&mat_data.materials,mat);
  56
  57         return mat;
  58 }
  59
  60 /* free a material */
  61 void mat_free(material_t *mat)
  62 {
  63         if (!mat)
  64                 return;
  65
  66         mat_data.materials = list_remove(&mat_data.materials,mat);
  67
  68         if (mat->tex)
  69                 tex_free(mat->tex);
  70
  71         free(mat);
  72 }
  73
  74 /* create a material from a texture */
  75 material_t *mat_from_tex(texture_t *tex)
  76 {
  77         material_t *mat = mat_create();
  78         mat->tex = tex;
  79         strcpy(mat->name,tex->name);
  80
  81         return mat;
  82 }
  83
  84 /* create a material from pixel data */
  85 material_t *mat_from_pixels(image_t *p)
  86 {
  87         material_t *mat = mat_create();
  88         mat->tex = tex_from_pixels(p);
  89         strcpy(mat->name,mat->tex->name);
  90
  91         return mat;
  92 }
  93
  94 /* update a material from pixel data */
  95 material_t *mat_update_pixels(material_t *mat, image_t *p)
  96 {
  97         if (!mat)
  98                 return mat_from_pixels(p);
  99
 100         mat->tex = tex_update_pixels(mat->tex,p);
 101
 102         return mat;
 103 }
 104
 105 /* create a material from an image */
 106 material_t *mat_from_image(char* type, char* file)
 107 {
 108         material_t *mat = mat_create();
 109
 110         mat->tex = tex_from_image(type,file);
 111         if (!mat->tex) {
 112                 mat_free(mat);
 113                 return NULL;
 114         }
 115
 116         strcpy(mat->name,mat->tex->name);
 117
 118         return mat;
 119 }
 120
 121 /* create a material from a colour */
 122 material_t *mat_from_colour(colour_t *c)
 123 {
 124         char buff[100];
 125         material_t *mat;
 126         snprintf(buff,100,"rgba-%d-%d-%d-%d",c->r,c->g,c->b,c->a);
 127
 128         mat = mat_create();
 129
 130         mat->tex = tex_from_rgba(1,1,c->r,c->g,c->b,c->a);
 131         if (!mat->tex) {
 132                 mat_free(mat);
 133                 return NULL;
 134         }
 135
 136         strcpy(mat->name,buff);
 137
 138         return mat;
 139 }
 140
 141 /* bind a texture and apply options */
 142 int mat_bind_with_opts(GLuint tex, uint32_t options)
 143 {
 144         GLenum e;
 145
 146         if (mat_data.current_texture != tex)
 147                 glBindTexture(GL_TEXTURE_2D,tex);
 148
 149         e = glGetError();
 150         if (e != GL_NO_ERROR) {
 151                 char* es = opengl_error_string(e);
 152                 vlprintf(CN_ERROR, "%s",es);
 153                 return 1;
 154         }
 155
 156         mat_data.current_texture = tex;
 157
 158         /* back face culling */
 159         if ((options&MATOPT_BFCULL) == MATOPT_BFCULL) {
 160                 if (!mat_data.culling) {
 161                         glEnable(GL_CULL_FACE);
 162                         glCullFace(GL_BACK);
 163                         mat_data.culling = 1;
 164                 }
 165         }else if (mat_data.culling) {
 166                 glDisable(GL_CULL_FACE);
 167                 mat_data.culling = 0;
 168         }
 169
 170         /* blending */
 171         if ((options&MATOPT_ADDITIVE_BLEND) == MATOPT_ADDITIVE_BLEND) {
 172                 if (!mat_data.blended) {
 173                         glEnable(GL_BLEND);
 174                         glEnable(GL_LINE_SMOOTH);
 175                         mat_data.blended = 1;
 176                 }
 177                 if (mat_data.blend_mode != GL_ONE) {
 178                         glBlendFunc(GL_SRC_ALPHA, GL_ONE);
 179                         mat_data.blend_mode = GL_ONE;
 180                 }
 181         }else if ((options&MATOPT_ALPHA_BLEND) == MATOPT_ALPHA_BLEND) {
 182                 if (!mat_data.blended) {
 183                         glEnable(GL_BLEND);
 184                         glEnable(GL_LINE_SMOOTH);
 185                         mat_data.blended = 1;
 186                 }
 187                 if (mat_data.blend_mode != GL_ONE_MINUS_SRC_ALPHA) {
 188                         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 189                         mat_data.blend_mode = GL_ONE_MINUS_SRC_ALPHA;
 190                 }
 191         }else if (mat_data.blended) {
 192                 glDisable(GL_BLEND);
 193                 mat_data.blended = 0;
 194                 mat_data.blend_mode = GL_ZERO;
 195         }
 196
 197         return 0;
 198 }
 199
 200 /* use a material */
 201 void mat_use(material_t *mat, shader_t *shader)
 202 {
 203         if (mat->tex) {
 204                 if (mat->tex->state != 1)
 205                         tex_generate(mat->tex);
 206                 if (mat_bind_with_opts(mat->tex->glid,mat->options))
 207                         mat->tex->state = 0;
 208         }else{
 209                 mat_bind_with_opts(0,mat->options);
 210         }
 211
 212         /* specular values */
 213         if (shader) {
 214                 shader_uniform_float(shader,"shininess",mat->shininess);
 215                 shader_uniform_float(shader,"reflectivity",mat->reflectivity);
 216                 shader_uniform_float(shader,"bumpiness",mat->bumpiness);
 217         }
 218 }
 219
 220 /* set the shininess and reflectivity of a material */
 221 void mat_shininess(material_t *mat, float shininess, float reflectivity)
 222 {
 223         mat->shininess = shininess;
 224         mat->reflectivity = reflectivity;
 225 }
 226
 227 /* set the bumpiness (for bump mapping) of a material */
 228 void mat_bumpiness(material_t *mat, float bumpiness)
 229 {
 230         mat->bumpiness = bumpiness;
 231 }
 232
 233 /* set the name of a material */
 234 void mat_name(material_t *mat, char* name)
 235 {
 236         strncpy(mat->name,name,100);
 237 }
 238
 239 /* set the texture of a material */
 240 void mat_tex(material_t *mat, texture_t *tex)
 241 {
 242         mat->tex = tex;
 243 }
 244
 245 /* set the texture of a material from an image file */
 246 void mat_tex_file(material_t *mat, char* type, char* file)
 247 {
 248         mat->tex = tex_from_image(type,file);
 249         strcpy(mat->name,mat->tex->name);
 250 }
 251
 252 /* set the options for a material, return the previous options */
 253 uint32_t mat_options(material_t *mat, uint32_t opt)
 254 {
 255         uint32_t o = mat->options;
 256         if (opt != MATOPT_GET)
 257                 mat->options = opt;
 258         return o;
 259 }