shaders/background.h

   1 #ifndef SHADER_background_H
   2 #define SHADER_background_H
   3 static void shader_background_link(void);
   4 static void shader_background_register(void);
   5 static struct vg_shader _shader_background = {
   6    .name = "background",
   7    .link = shader_background_link,
   8    .vs =
   9 {
  10 .orig_file = "shaders/background.vs.glsl",
  11 .static_src =
  12 "layout (location=0) in vec2 a_co;\n"
  13 "uniform mat3 uPv;\n"
  14 "uniform vec3 uOffset;\n"
  15 "\n"
  16 "out vec2 aTexCoords;\n"
  17 "\n"
  18 "void main(){\n"
  19 "   vec2 world_pos = a_co * uOffset.z + uOffset.xy;\n"
  20 "   gl_Position = vec4( uPv * vec3( world_pos, 1.0 ), 1.0 );\n"
  21 "   aTexCoords = a_co;\n"
  22 "}\n"
  23 ""},
  24    .fs =
  25 {
  26 .orig_file = "shaders/background.fs.glsl",
  27 .static_src =
  28 "out vec4 FragColor;\n"
  29 "\n"
  30 "uniform sampler2D uTexMain;\n"
  31 "uniform sampler2D uSamplerNoise;\n"
  32 "uniform float uVariance;\n"
  33 "uniform float uVisibility;\n"
  34 "\n"
  35 "in vec2 aTexCoords;\n"
  36 "\n"
  37 "void main(){\n"
  38 "   vec4 data_this_tile = texture( uTexMain, aTexCoords );\n"
  39 "\n"
  40 "   float ao_accum = 0.0;\n"
  41 "   vec2 random_noise;\n"
  42 "\n"
  43 "   for( int i=0; i<10; ++i ){\n"
  44 "       random_noise = (texture( uSamplerNoise, \n"
  45 "                               aTexCoords*10.0 + float(i)*0.2 ).xy - vec2(0.5)) \n"
  46 "                               * uVariance;\n"
  47 "       vec4 background = texture( uTexMain, aTexCoords + random_noise );\n"
  48 "      float height_diff = min(data_this_tile.r - background.r,0.0);\n"
  49 "       ao_accum += height_diff * clamp((1.0 - length( random_noise )), 0.0, 1.0);\n"
  50 "   }\n"
  51 "   ao_accum *= 0.15;\n"
  52 "\n"
  53 "   vec2 square_coords = fract( aTexCoords * 64.0 );\n"
  54 "   vec2 grid_coords = abs( square_coords - 0.5 );\n"
  55 "   float gridline = step( 0.49, max(grid_coords.x,grid_coords.y) );\n"
  56 "\n"
  57 "   vec3 colour_main = mix( vec3( 0.14 ) + random_noise.x*0.5, \n"
  58 "                           vec3( 0.1 ) + gridline*0.02, \n"
  59 "                           data_this_tile.g * uVisibility );\n"
  60 "   FragColor = vec4( colour_main + ao_accum*0.05, 1.0 );\n"
  61 "}\n"
  62 ""},
  63 };
  64
  65 static GLuint _uniform_background_uPv;
  66 static GLuint _uniform_background_uOffset;
  67 static GLuint _uniform_background_uTexMain;
  68 static GLuint _uniform_background_uSamplerNoise;
  69 static GLuint _uniform_background_uVariance;
  70 static GLuint _uniform_background_uVisibility;
  71 static void shader_background_uPv(m3x3f m){
  72    glUniformMatrix3fv(_uniform_background_uPv,1,GL_FALSE,(float*)m);
  73 }
  74 static void shader_background_uOffset(v3f const v){
  75    glUniform3fv(_uniform_background_uOffset,1,v);
  76 }
  77 static void shader_background_uTexMain(int i){
  78    glUniform1i(_uniform_background_uTexMain,i);
  79 }
  80 static void shader_background_uSamplerNoise(int i){
  81    glUniform1i(_uniform_background_uSamplerNoise,i);
  82 }
  83 static void shader_background_uVariance(float f){
  84    glUniform1f(_uniform_background_uVariance,f);
  85 }
  86 static void shader_background_uVisibility(float f){
  87    glUniform1f(_uniform_background_uVisibility,f);
  88 }
  89 static void shader_background_register(void){
  90    vg_shader_register( &_shader_background );
  91 }
  92 static void shader_background_use(void){ glUseProgram(_shader_background.id); }
  93 static void shader_background_link(void){
  94    _uniform_background_uPv = glGetUniformLocation( _shader_background.id, "uPv" );
  95    _uniform_background_uOffset = glGetUniformLocation( _shader_background.id, "uOffset" );
  96    _uniform_background_uTexMain = glGetUniformLocation( _shader_background.id, "uTexMain" );
  97    _uniform_background_uSamplerNoise = glGetUniformLocation( _shader_background.id, "uSamplerNoise" );
  98    _uniform_background_uVariance = glGetUniformLocation( _shader_background.id, "uVariance" );
  99    _uniform_background_uVisibility = glGetUniformLocation( _shader_background.id, "uVisibility" );
 100 }
 101 #endif /* SHADER_background_H */