3 This file is part of libmspgl
4 Copyright © 2010-2011 Mikko Rasa, Mikkosoft Productions
5 Distributed under the LGPL
9 #include "ambientocclusion.h"
11 #include "meshbuilder.h"
16 const char vertex_shader[] =
17 "varying vec2 texcoord;\n"
20 " gl_Position = gl_Vertex;\n"
21 " texcoord = gl_Vertex.xy*0.5+0.5;\n"
24 const char occlude_fs[] =
25 "uniform sampler2D depth;\n"
26 "uniform sampler2D rotate;\n"
27 "uniform vec2 screen_size;\n"
28 "uniform vec2 depth_ratio;\n"
29 "uniform float darkness;\n"
30 "varying vec2 texcoord;\n"
33 " mat2 transform = mat2(texture2D(rotate, texcoord*screen_size/4.0)*2.0-1.0)\n"
34 " *mat2(screen_size.y/screen_size.x, 0.0, 0.0, 1.0)*3.0/screen_size.y;\n"
35 " float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
37 " for(int i=0; i<=3; ++i)\n"
38 " for(int j=0; j<=3; ++j)\n"
40 " vec2 offs = transform*vec2(float(i)-1.5, float(j)-1.5);\n"
41 " float dxy = length(offs)*-sample;\n"
42 " float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
43 " if(abs(dz)<3*dxy)\n"
44 " sum += atan(dz/dxy)/1.570796;\n"
48 " gl_FragColor = vec4(min(1.0-sum*darkness/16.0, 1.0), 0.0, 0.0, 1.0);\n"
51 const char combine_fs[] =
52 "uniform sampler2D color;\n"
53 "uniform sampler2D depth;\n"
54 "uniform sampler2D occlusion;\n"
55 "uniform vec2 screen_size;\n"
56 "uniform vec2 depth_ratio;\n"
57 "varying vec2 texcoord;\n"
60 " float sample = depth_ratio.x/(texture2D(depth, texcoord).r-depth_ratio.y);\n"
62 " float count = 1.0;\n"
63 " for(int i=0; i<=3; ++i)\n"
64 " for(int j=0; j<=3; ++j)\n"
66 " vec2 offs = vec2(float(i)-1.5, float(j)-1.5)/screen_size;\n"
67 " float dxy = length(offs)*-sample;\n"
68 " float dz = depth_ratio.x/(texture2D(depth, texcoord+offs).r-depth_ratio.y)-sample;\n"
69 " if(abs(dz)<3*dxy)\n"
71 " sum += texture2D(occlusion, texcoord+offs).r;\n"
75 " gl_FragColor = texture2D(color, texcoord)*sum/count;\n"
83 AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
84 occlude_shader(vertex_shader, occlude_fs),
85 occlude_shdata(occlude_shader),
86 combine_shader(vertex_shader, combine_fs),
87 combine_shdata(combine_shader),
90 occlusion.storage(GL::RGB, w, h);
91 occlusion.set_min_filter(GL::NEAREST);
92 occlusion.set_mag_filter(GL::NEAREST);
93 fbo.attach(COLOR_ATTACHMENT0, occlusion, 0);
95 combine_texturing.attach(2, occlusion);
97 rotate_lookup.storage(GL::RGBA, 4, 4);
98 rotate_lookup.set_min_filter(GL::NEAREST);
99 rotate_lookup.set_mag_filter(GL::NEAREST);
100 unsigned char data[64];
101 for(unsigned i=0; i<16; ++i)
103 float a = ((i*541)%16)*M_PI/32;
106 data[i*3 ] = static_cast<unsigned char>(127+c*127);
107 data[i*3+1] = static_cast<unsigned char>(127+s*127);
108 data[i*3+2] = static_cast<unsigned char>(127-s*127);
109 data[i*3+4] = static_cast<unsigned char>(127+c*127);
111 rotate_lookup.image(0, GL::RGBA, GL::UNSIGNED_BYTE, data);
113 occlude_texturing.attach(1, rotate_lookup);
115 occlude_shdata.uniform("depth", 0);
116 occlude_shdata.uniform("rotate", 1);
117 occlude_shdata.uniform("screen_size", w, h);
119 combine_shdata.uniform("color", 1);
120 combine_shdata.uniform("depth", 0);
121 combine_shdata.uniform("occlusion", 2);
122 combine_shdata.uniform("screen_size", w, h);
124 set_depth_ratio(depth_ratio);
127 MeshBuilder bld(quad);
128 bld.begin(TRIANGLE_STRIP);
136 void AmbientOcclusion::set_depth_ratio(float depth_ratio)
138 depth_ratio = 1/depth_ratio;
140 occlude_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
141 combine_shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
144 void AmbientOcclusion::set_darkness(float darkness)
146 occlude_shdata.uniform("darkness", darkness);
149 void AmbientOcclusion::render(const Texture2D &color, const Texture2D &depth)
151 occlude_texturing.attach(0, depth);
152 combine_texturing.attach(0, depth);
153 combine_texturing.attach(1, color);
155 Bind unbind_dtest(static_cast<DepthTest *>(0), true);
156 Bind unbind_blend(static_cast<Blend *>(0), true);
159 GL::Bind bind_fbo(fbo, true);
160 GL::Bind bind_tex(occlude_texturing);
161 GL::Bind bind_shader(occlude_shader);
162 occlude_shdata.apply();
166 GL::Bind bind_tex(combine_texturing);
167 GL::Bind bind_shader(combine_shader);
168 combine_shdata.apply();