vg/vg_tex.h

   1 // Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
   2
   3 #define VG_TEXTURE_NO_MIP       0x1
   4 #define VG_TEXTURE_REPEAT       0x2
   5 #define VG_TEXTURE_CLAMP        0x4
   6 #define VG_TEXTURE_NEAREST      0x8
   7
   8 struct vg_tex2d
   9 {
  10         const char *path;
  11         u32 flags;
  12         GLuint name;
  13 };
  14
  15 static void vg_tex2d_bind( vg_tex2d *tex, u32 id )
  16 {
  17         glActiveTexture( GL_TEXTURE0 + id );
  18         glBindTexture( GL_TEXTURE_2D, tex->name );
  19 }
  20
  21 static inline void vg_tex2d_mipmap(void)
  22 {
  23         glGenerateMipmap( GL_TEXTURE_2D );
  24 }
  25
  26 static inline void vg_tex2d_linear(void)
  27 {
  28         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
  29         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  30 }
  31
  32 static inline void vg_tex2d_nearest(void)
  33 {
  34         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  35         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
  36 }
  37
  38 static inline void vg_tex2d_linear_mipmap(void)
  39 {
  40         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
  41         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  42 }
  43
  44 static inline void vg_tex2d_repeat(void)
  45 {
  46         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
  47         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
  48 }
  49
  50 static inline void vg_tex2d_clamp(void)
  51 {
  52         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
  53         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
  54 }
  55
  56 static GLuint vg_tex2d_rgba( const char *path )
  57 {
  58         i64 length;
  59         u8 *src_data = vg_asset_read_s( path, &length );
  60
  61         GLuint texture_name;
  62         glGenTextures( 1, &texture_name );
  63         glBindTexture( GL_TEXTURE_2D, texture_name );
  64
  65         if( src_data )
  66         {
  67                 qoi_desc info;
  68                 u8 *tex_buffer = qoi_decode( src_data, length, &info, 4 );
  69
  70                 glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, info.width, info.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, tex_buffer );
  71
  72                 free( tex_buffer );
  73                 free( src_data );
  74         }
  75         else
  76         {
  77                 u32 tex_err[4] =
  78                 {
  79                         0xffff00ff,
  80                         0xff000000,
  81                         0xff000000,
  82                         0xffff00ff
  83                 };
  84
  85                 vg_error( "Loading texture failed (%s)\n", path );
  86                 glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0, GL_RGBA, GL_UNSIGNED_BYTE, tex_err );
  87         }
  88
  89         return texture_name;
  90 }
  91
  92 static void vg_tex2d_init( vg_tex2d *textures[], int num )
  93 {
  94         for( int i = 0; i < num; i ++ )
  95         {
  96                 vg_tex2d *tex = textures[i];
  97                 tex->name = vg_tex2d_rgba( tex->path );
  98                 if( !(tex->flags & VG_TEXTURE_NO_MIP) )
  99                         vg_tex2d_mipmap();
 100
 101                 if( tex->flags & VG_TEXTURE_NEAREST )
 102                 {
 103                         if( tex->flags & VG_TEXTURE_NO_MIP )
 104                                 vg_error( "Invalid texture settings\n" );
 105                         else
 106                                 vg_tex2d_nearest();
 107                 }
 108                 else
 109                 {
 110                         if( tex->flags & VG_TEXTURE_NO_MIP )
 111                                 vg_tex2d_linear();
 112                         else
 113                                 vg_tex2d_linear_mipmap();
 114                 }
 115
 116                 if( tex->flags & VG_TEXTURE_CLAMP )
 117                         vg_tex2d_clamp();
 118                 else
 119                         vg_tex2d_repeat();
 120         }
 121 }
 122
 123 static void vg_tex2d_free( vg_tex2d *textures[], int num )
 124 {
 125         for( int i = 0; i < num; i ++ )
 126         {
 127                 glDeleteTextures( 1, &textures[i]->name );
 128         }
 129 }