Make ambient occlusion edge detection threshold adjustable

[libs/gl.git] / source / ambientocclusion.cpp

diff --git a/source/ambientocclusion.cpp b/source/ambientocclusion.cpp
index 1b078cdc116a187a718e9d92b8ef97b3fd84f5ec..ed7d1636d711d34ee6539fd4ddb11adbb4677f44 100644 (file)
--- a/source/ambientocclusion.cpp
+++ b/source/ambientocclusion.cpp
@@ -1,35 +1,38 @@
-#define _USE_MATH_DEFINES
-#include <cmath>
+#include <algorithm>
 #include "ambientocclusion.h"
 #include "blend.h"
+#include "camera.h"
 #include "renderer.h"
 #include "shader.h"
 #include "tests.h"
 
+using namespace std;
+
 namespace Msp {
 namespace GL {
 
-AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
-       occlude_target(w, h, (RENDER_COLOR,RGB)),
+AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float):
+       occlude_target(w, h, (RENDER_COLOR,RED)),
        occlude_shader("ambientocclusion_occlude.glsl"),
        combine_shader("ambientocclusion_combine.glsl"),
        quad(get_fullscreen_quad())
 {
+       occlude_target.set_texture_filter(LINEAR);
        texturing.attach(2, occlude_target.get_target_texture(RENDER_COLOR));
 
-       rotate_lookup.storage(RGBA, 4, 4);
-       rotate_lookup.set_min_filter(NEAREST);
-       rotate_lookup.set_mag_filter(NEAREST);
+       unsigned seed = 1;
+       rotate_lookup.storage(RGBA, 4, 4, 1);
+       rotate_lookup.set_filter(NEAREST);
        unsigned char data[64];
        for(unsigned i=0; i<16; ++i)
        {
-               float a = ((i*541)%16)*M_PI/32;
-               float c = cos(a);
-               float s = sin(a);
-               data[i*3  ] = static_cast<unsigned char>(127+c*127);
-               data[i*3+1] = static_cast<unsigned char>(127+s*127);
-               data[i*3+2] = static_cast<unsigned char>(127-s*127);
-               data[i*3+4] = static_cast<unsigned char>(127+c*127);
+               Geometry::Angle<float> a = Geometry::Angle<float>::from_turns(random(seed));
+               unsigned char c = (cos(a)*0.5f+0.5f)*255;
+               unsigned char s = (sin(a)*0.5f+0.5f)*255;
+               data[i*4  ] = c;
+               data[i*4+1] = s;
+               data[i*4+2] = 255-s;
+               data[i*4+3] = ((i+i/4)%2)*255;
        }
        rotate_lookup.image(0, RGBA, UNSIGNED_BYTE, data);
 
@@ -39,17 +42,45 @@ AmbientOcclusion::AmbientOcclusion(unsigned w, unsigned h, float depth_ratio):
        shdata.uniform("depth", 1);
        shdata.uniform("occlusion", 2);
        shdata.uniform("rotate", 3);
-       shdata.uniform("screen_size", static_cast<float>(w), static_cast<float>(h));
+       shdata.uniform("inverse_projection", Matrix());
+
+       set_n_samples(16);
+       set_occlusion_radius(0.5f);
+       set_darkness(1.0f);
+       set_edge_depth_threshold(0.1f);
+}
 
-       set_depth_ratio(depth_ratio);
-       set_darkness(1.5);
+float AmbientOcclusion::random(unsigned &seed)
+{
+       static const unsigned modulus = (1U<<31)-1;
+       seed = (static_cast<UInt64>(seed)*48271)%modulus;  // minstd
+       return static_cast<float>(seed)/(modulus-1);
 }
 
-void AmbientOcclusion::set_depth_ratio(float depth_ratio)
+void AmbientOcclusion::set_n_samples(unsigned n)
 {
-       depth_ratio = 1/depth_ratio;
+       if(n<1 || n>32)
+               throw out_of_range("AmbientOcclusion::set_n_samples");
 
-       shdata.uniform("depth_ratio", depth_ratio, 1+depth_ratio);
+       unsigned seed = 1;
+       float radius_divisor = (n-1)*(n-1);
+       Vector3 sample_points[32];
+       for(unsigned i=0; i<n; ++i)
+       {
+               Vector3 v(random(seed)-0.5f, random(seed)-0.5f, random(seed)-0.5f);
+               sample_points[i] = normalize(v)*(0.1f+0.9f*i*i/radius_divisor);
+       }
+       shdata.uniform3_array("sample_points", n, &sample_points[0].x);
+       shdata.uniform("n_samples", static_cast<int>(n));
+}
+
+void AmbientOcclusion::set_occlusion_radius(float r)
+{
+       shdata.uniform("occlusion_radius", r);
+}
+
+void AmbientOcclusion::set_depth_ratio(float)
+{
 }
 
 void AmbientOcclusion::set_darkness(float darkness)
@@ -57,11 +88,19 @@ void AmbientOcclusion::set_darkness(float darkness)
        shdata.uniform("darkness", darkness);
 }
 
+void AmbientOcclusion::set_edge_depth_threshold(float edt)
+{
+       shdata.uniform("edge_depth_threshold", edt);
+}
+
 void AmbientOcclusion::render(Renderer &renderer, const Texture2D &color, const Texture2D &depth)
 {
        texturing.attach(0, color);
        texturing.attach(1, depth);
 
+       if(renderer.get_camera())
+               shdata.uniform("inverse_projection", invert(renderer.get_camera()->get_projection_matrix()));
+
        Renderer::Push push(renderer);
        renderer.set_texturing(&texturing);
        renderer.set_shader_program(&occlude_shader, &shdata);
@@ -75,5 +114,33 @@ void AmbientOcclusion::render(Renderer &renderer, const Texture2D &color, const
        quad.draw(renderer);
 }
 
+
+AmbientOcclusion::Template::Template():
+       n_samples(16),
+       occlusion_radius(0.5f),
+       darkness(1.0f),
+       edge_depth_threshold(0.1f)
+{ }
+
+AmbientOcclusion *AmbientOcclusion::Template::create(unsigned width, unsigned height) const
+{
+       RefPtr<AmbientOcclusion> ao = new AmbientOcclusion(width/size_divisor, height/size_divisor);
+       ao->set_n_samples(n_samples);
+       ao->set_occlusion_radius(occlusion_radius);
+       ao->set_darkness(darkness);
+       ao->set_edge_depth_threshold(edge_depth_threshold);
+       return ao.release();
+}
+
+
+AmbientOcclusion::Template::Loader::Loader(Template &t):
+       DataFile::DerivedObjectLoader<Template, PostProcessor::Template::Loader>(t)
+{
+       add("darkness", &Template::darkness);
+       add("edge_depth_threshold", &Template::edge_depth_threshold);
+       add("occlusion_radius", &Template::occlusion_radius);
+       add("samples", &Template::n_samples);
+}
+
 } // namespace GL
 } // namespace Msp