src/vg/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 struct vg_tex2d
  15 {
  16         const char *path;
  17         u32 flags;
  18         GLuint name;
  19 };
  20
  21 struct vg_sprite
  22 {
  23         v4f uv_xywh;
  24 };
  25
  26 static void vg_tex2d_bind( vg_tex2d *tex, u32 id )
  27 {
  28    if( !(tex->flags & VG_TEXTURE_ALLOCATED_INTERNAL) )
  29    {
  30       vg_error( "Tried to use '%s' while unloaded!\n", tex->path );
  31       return;
  32    }
  33
  34         glActiveTexture( GL_TEXTURE0 + id );
  35         glBindTexture( GL_TEXTURE_2D, tex->name );
  36 }
  37
  38 static inline void vg_tex2d_mipmap(void)
  39 {
  40         glGenerateMipmap( GL_TEXTURE_2D );
  41 }
  42
  43 static inline void vg_tex2d_linear(void)
  44 {
  45         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
  46         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  47 }
  48
  49 static inline void vg_tex2d_nearest(void)
  50 {
  51         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
  52         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
  53 }
  54
  55 static inline void vg_tex2d_linear_mipmap(void)
  56 {
  57         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
  58          GL_LINEAR_MIPMAP_LINEAR );
  59         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
  60 }
  61
  62 static inline void vg_tex2d_repeat(void)
  63 {
  64         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
  65         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
  66 }
  67
  68 static inline void vg_tex2d_clamp(void)
  69 {
  70         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
  71         glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
  72 }
  73
  74 static GLuint vg_tex2d_rgba( const char *path )
  75 {
  76         i64 length;
  77         u8 *src_data = vg_asset_read_s( path, &length );
  78
  79         GLuint texture_name;
  80         glGenTextures( 1, &texture_name );
  81         glBindTexture( GL_TEXTURE_2D, texture_name );
  82
  83         if( src_data )
  84         {
  85                 qoi_desc info;
  86                 u8 *tex_buffer = qoi_decode( src_data, length, &info, 4 );
  87
  88                 glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, info.width, info.height,
  89             0, GL_RGBA, GL_UNSIGNED_BYTE, tex_buffer );
  90
  91                 free( tex_buffer );
  92                 free( src_data );
  93         }
  94         else
  95         {
  96                 u32 tex_err[4] =
  97                 {
  98                         0xffff00ff,
  99                         0xff000000,
 100                         0xff000000,
 101                         0xffff00ff
 102                 };
 103
 104                 vg_error( "Loading texture failed (%s)\n", path );
 105                 glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, 2, 2,
 106             0, GL_RGBA, GL_UNSIGNED_BYTE, tex_err );
 107         }
 108
 109         return texture_name;
 110 }
 111
 112 static void vg_tex2d_init( vg_tex2d *textures[], int num )
 113 {
 114         for( int i=0; i<num; i ++ )
 115         {
 116                 vg_tex2d *tex = textures[i];
 117                 tex->name = vg_tex2d_rgba( tex->path );
 118                 if( !(tex->flags & VG_TEXTURE_NO_MIP) )
 119                         vg_tex2d_mipmap();
 120
 121                 if( tex->flags & VG_TEXTURE_NEAREST )
 122                 {
 123                         if( tex->flags & VG_TEXTURE_NO_MIP )
 124                                 vg_error( "Invalid texture settings\n" );
 125                         else
 126                                 vg_tex2d_nearest();
 127                 }
 128                 else
 129                 {
 130                         if( tex->flags & VG_TEXTURE_NO_MIP )
 131                                 vg_tex2d_linear();
 132                         else
 133                                 vg_tex2d_linear_mipmap();
 134                 }
 135
 136                 if( tex->flags & VG_TEXTURE_CLAMP )
 137                         vg_tex2d_clamp();
 138                 else
 139                         vg_tex2d_repeat();
 140
 141       tex->flags |= VG_TEXTURE_ALLOCATED_INTERNAL;
 142         }
 143 }
 144
 145 static void vg_tex2d_free( vg_tex2d *textures[], int num )
 146 {
 147         for( int i = 0; i < num; i ++ )
 148         {
 149                 glDeleteTextures( 1, &textures[i]->name );
 150         }
 151 }
 152
 153 #endif /* VG_TEX_H */