vg_tex.h

   1 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
   2 #ifndef VG_TEX_H
   3 #define VG_TEX_H
   4
   5 #include "vg/vg.h"
   6 #include "vg/vg_log.h"
   7
   8 #define VG_TEXTURE_NO_MIP       0x1
   9 #define VG_TEXTURE_REPEAT       0x2
  10 #define VG_TEXTURE_CLAMP        0x4
  11 #define VG_TEXTURE_NEAREST      0x8
  12 #define VG_TEXTURE_ALLOCATED_INTERNAL 0x10
  13
  14 VG_STATIC void *vg_qoi_malloc( size_t size )
  15 {
  16    return vg_linear_alloc( vg_mem.scratch, size );
  17 }
  18
  19 VG_STATIC void vg_qoi_free( void *ptr )
  20 {
  21
  22 }
  23
  24 #define QOI_IMPLEMENTATION
  25 #define QOI_NO_STDIO
  26 #define QOI_MALLOC(sz) vg_qoi_malloc( sz )
  27 #define QOI_FREE(p) vg_qoi_free( p )
  28
  29 #include "submodules/qoi/qoi.h"
  30
  31 struct vg_tex2d
  32 {
  33         const char *path;
  34         u32 flags;
  35         GLuint name;
  36 };
  37
  38 struct vg_sprite
  39 {
  40         v4f uv_xywh;
  41 };
  42
  43 VG_STATIC void vg_tex2d_bind( vg_tex2d *tex, u32 id )
  44 {
  45    if( !(tex->flags & VG_TEXTURE_ALLOCATED_INTERNAL) )
  46    {
  47       vg_error( "Tried to use '%s' while unloaded!\n", tex->path );
  48       return;
  49    }
  50
  51         glActiveTexture( GL_TEXTURE0 + id );
  52         glBindTexture( GL_TEXTURE_2D, tex->name );
  53 }
  54
  55 static inline void vg_tex2d_mipmap(void)
  56 {
  57         glGenerateMipmap( GL_TEXTURE_2D );
  58 }
  59
  60 static inline void vg_tex2d_linear(void)
  61 {
  62         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
  63         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  64 }
  65
  66 static inline void vg_tex2d_nearest(void)
  67 {
  68         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  69         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
  70 }
  71
  72 static inline void vg_tex2d_linear_mipmap(void)
  73 {
  74         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
  75          GL_LINEAR_MIPMAP_LINEAR );
  76         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  77 }
  78
  79 static inline void vg_tex2d_repeat(void)
  80 {
  81         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
  82         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
  83 }
  84
  85 static inline void vg_tex2d_clamp(void)
  86 {
  87         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
  88         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
  89 }
  90
  91 VG_STATIC GLuint vg_tex2d_new(void)
  92 {
  93         GLuint texture_name;
  94         glGenTextures( 1, &texture_name );
  95         glBindTexture( GL_TEXTURE_2D, texture_name );
  96
  97    return texture_name;
  98 }
  99
 100 VG_STATIC void vg_tex2d_set_error(void)
 101 {
 102    u32 tex_err[4] =
 103    {
 104       0xffff00ff,
 105       0xff000000,
 106       0xff000000,
 107       0xffff00ff
 108    };
 109
 110    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, 2, 2,
 111                   0, GL_RGBA, GL_UNSIGNED_BYTE, tex_err );
 112 }
 113
 114 VG_STATIC void vg_tex2d_qoi( void *mem, u32 size, const char *name )
 115 {
 116    qoi_desc info;
 117    u8 *tex_buffer = qoi_decode( mem, size, &info, 4 );
 118
 119    if( tex_buffer )
 120    {
 121       vg_info( "Texture decoded: [%u %u] %s\n",
 122                                     info.width, info.height, name );
 123
 124       glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, info.width, info.height,
 125                     0, GL_RGBA, GL_UNSIGNED_BYTE, tex_buffer );
 126
 127       QOI_FREE(tex_buffer);
 128    }
 129    else
 130    {
 131       vg_error( "File size: %u\n", size );
 132       vg_tex2d_set_error();
 133    }
 134 }
 135
 136 VG_STATIC GLuint vg_tex2d_rgba( const char *path )
 137 {
 138    GLuint texture_name = vg_tex2d_new();
 139
 140    vg_linear_clear( vg_mem.scratch );
 141    u32 size;
 142    void *file = vg_file_read( vg_mem.scratch, path, &size );
 143
 144    if( file )
 145    {
 146       vg_tex2d_qoi( file, size, path );
 147    }
 148    else
 149    {
 150                 vg_error( "Loading texture failed (%s)\n", path );
 151       vg_tex2d_set_error();
 152    }
 153
 154         return texture_name;
 155 }
 156
 157 VG_STATIC void vg_tex2d_init( vg_tex2d *textures[], int num )
 158 {
 159         for( int i=0; i<num; i ++ )
 160         {
 161                 vg_tex2d *tex = textures[i];
 162                 tex->name = vg_tex2d_rgba( tex->path );
 163                 if( !(tex->flags & VG_TEXTURE_NO_MIP) )
 164                         vg_tex2d_mipmap();
 165
 166                 if( tex->flags & VG_TEXTURE_NEAREST )
 167                 {
 168                         if( tex->flags & VG_TEXTURE_NO_MIP )
 169                                 vg_error( "Invalid texture settings\n" );
 170                         else
 171                                 vg_tex2d_nearest();
 172                 }
 173                 else
 174                 {
 175                         if( tex->flags & VG_TEXTURE_NO_MIP )
 176                                 vg_tex2d_linear();
 177                         else
 178                                 vg_tex2d_linear_mipmap();
 179                 }
 180
 181                 if( tex->flags & VG_TEXTURE_CLAMP )
 182                         vg_tex2d_clamp();
 183                 else
 184                         vg_tex2d_repeat();
 185
 186       tex->flags |= VG_TEXTURE_ALLOCATED_INTERNAL;
 187         }
 188 }
 189
 190 VG_STATIC void vg_tex2d_free( vg_tex2d *textures[], int num )
 191 {
 192         for( int i = 0; i < num; i ++ )
 193         {
 194                 glDeleteTextures( 1, &textures[i]->name );
 195         }
 196 }
 197
 198 #endif /* VG_TEX_H */