source/ambientocclusion.cpp

   1 #define _USE_MATH_DEFINES
   2 #include <cmath>
   3 #include "ambientocclusion.h"
   4 #include "blend.h"
   5 #include "shader.h"
   6 #include "tests.h"
   7
   8 namespace {
   9
  10 const char occlude_fs[] =
  11         "uniform sampler2D depth;\n"
  12         "uniform sampler2D rotate;\n"
  13         "uniform vec2 screen_size;\n"
  14         "uniform vec2 depth_ratio;\n"
  15         "uniform float darkness;\n"
  16         "varying vec2 texcoord;\n"
  17         "void main()\n"
  18         "{\n"
  19         "       mat2 transform = mat2(texture2D(rotate, texcoord*screen_size/4.0)*2.0-1.0)\n"
  20         "               *mat2(screen_size.y/screen_size.x, 0.0, 0.0, 1.0)*3.0/screen_size.y;\n"
  21         "       float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
  22         "       float sum = 0.0;\n"
  23         "       for(int i=0; i<=3; ++i)\n"
  24         "               for(int j=0; j<=3; ++j)\n"
  25         "               {\n"
  26         "                       vec2 offs = transform*vec2(float(i)-1.5, float(j)-1.5);\n"
  27         "                       float dxy = length(offs)*-sample;\n"
  28         "                       float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
  29         "                       if(abs(dz)<3.0*dxy)\n"
  30         "                               sum += atan(dz/dxy)/1.570796;\n"
  31         "                       else if(dz<0.0)\n"
  32         "                               sum -= 0.8;\n"
  33         "               }\n"
  34         "       gl_FragColor = vec4(min(1.0-sum*darkness/16.0, 1.0), 0.0, 0.0, 1.0);\n"
  35         "}\n";
  36
  37 const char combine_fs[] =
  38         "uniform sampler2D color;\n"
  39         "uniform sampler2D depth;\n"
  40         "uniform sampler2D occlusion;\n"
  41         "uniform vec2 screen_size;\n"
  42         "uniform vec2 depth_ratio;\n"
  43         "varying vec2 texcoord;\n"
  44         "void main()\n"
  45         "{\n"
  46         "       float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
  47         "       float sum = 1.0;\n"
  48         "       float count = 1.0;\n"
  49         "       for(int i=0; i<=3; ++i)\n"
  50         "               for(int j=0; j<=3; ++j)\n"
  51         "               {\n"
  52         "                       vec2 offs = vec2(float(i)-1.5, float(j)-1.5)/screen_size;\n"
  53         "                       float dxy = length(offs)*-sample;\n"
  54         "                       float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
  55         "                       if(abs(dz)<3.0*dxy)\n"
  56         "                       {\n"
  57         "                               sum += texture2D(occlusion, texcoord+offs).r;\n"
  58         "                               count += 1.0;\n"
  59         "                       }\n"
  60         "               }\n"
  61         "       gl_FragColor = texture2D(color, texcoord)*sum/count;\n"
  62         "}\n";
  63
  64 }
  65
  66 namespace Msp {
  67 namespace GL {
  68
  69 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
  70         quad(get_fullscreen_quad())
  71 {
  72         occlude_shader.attach_shader(get_fullscreen_vertex_shader());
  73         occlude_shader.attach_shader_owned(new FragmentShader(occlude_fs));
  74         occlude_shader.bind_attribute(get_component_type(VERTEX2), "vertex");
  75         occlude_shader.link();
  76
  77         combine_shader.attach_shader(get_fullscreen_vertex_shader());
  78         combine_shader.attach_shader_owned(new FragmentShader(combine_fs));
  79         combine_shader.bind_attribute(get_component_type(VERTEX2), "vertex");
  80         combine_shader.link();
  81
  82         occlusion.storage(RGB, w, h);
  83         occlusion.set_min_filter(NEAREST);
  84         occlusion.set_mag_filter(NEAREST);
  85         occlusion.set_wrap(CLAMP_TO_EDGE);
  86         fbo.attach(COLOR_ATTACHMENT0, occlusion, 0);
  87         fbo.require_complete();
  88
  89         combine_texturing.attach(2, occlusion);
  90
  91         rotate_lookup.storage(RGBA, 4, 4);
  92         rotate_lookup.set_min_filter(NEAREST);
  93         rotate_lookup.set_mag_filter(NEAREST);
  94         unsigned char data[64];
  95         for(unsigned i=0; i<16; ++i)
  96         {
  97                 float a = ((i*541)%16)*M_PI/32;
  98                 float c = cos(a);
  99                 float s = sin(a);
 100                 data[i*3  ] = static_cast<unsigned char>(127+c*127);
 101                 data[i*3+1] = static_cast<unsigned char>(127+s*127);
 102                 data[i*3+2] = static_cast<unsigned char>(127-s*127);
 103                 data[i*3+4] = static_cast<unsigned char>(127+c*127);
 104         }
 105         rotate_lookup.image(0, RGBA, UNSIGNED_BYTE, data);
 106
 107         occlude_texturing.attach(1, rotate_lookup);
 108
 109         occlude_shdata.uniform("depth", 0);
 110         occlude_shdata.uniform("rotate", 1);
 111         occlude_shdata.uniform("screen_size", w, h);
 112
 113         combine_shdata.uniform("color", 1);
 114         combine_shdata.uniform("depth", 0);
 115         combine_shdata.uniform("occlusion", 2);
 116         combine_shdata.uniform("screen_size", w, h);
 117
 118         set_depth_ratio(depth_ratio);
 119         set_darkness(1.5);
 120 }
 121
 122 void AmbientOcclusion::set_depth_ratio(float depth_ratio)
 123 {
 124         depth_ratio = 1/depth_ratio;
 125
 126         occlude_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
 127         combine_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
 128 }
 129
 130 void AmbientOcclusion::set_darkness(float darkness)
 131 {
 132         occlude_shdata.uniform("darkness", darkness);
 133 }
 134
 135 void AmbientOcclusion::render(const Texture2D &color, const Texture2D &depth)
 136 {
 137         occlude_texturing.attach(0, depth);
 138         combine_texturing.attach(0, depth);
 139         combine_texturing.attach(1, color);
 140
 141         BindRestore unbind_dtest(static_cast<DepthTest *>(0));
 142         BindRestore unbind_blend(static_cast<Blend *>(0));
 143         Bind bind_mesh(quad);
 144
 145         {
 146                 BindRestore bind_fbo(fbo);
 147                 Bind bind_tex(occlude_texturing);
 148                 Bind bind_shader(occlude_shader);
 149                 occlude_shdata.apply();
 150                 quad.draw();
 151         }
 152
 153         Bind bind_tex(combine_texturing);
 154         Bind bind_shader(combine_shader);
 155         combine_shdata.apply();
 156         quad.draw();
 157 }
 158
 159 } // namespace GL
 160 } // namespace Msp