source/shadowmap.cpp

   1 #include <cmath>
   2 #include <cstdlib>
   3 #include "camera.h"
   4 #include "light.h"
   5 #include "renderer.h"
   6 #include "scene.h"
   7 #include "shadowmap.h"
   8 #include "tests.h"
   9
  10 using namespace std;
  11
  12 namespace Msp {
  13 namespace GL {
  14
  15 ShadowMap::ShadowMap(unsigned s, Renderable &r, const Light &l):
  16         Effect(r),
  17         size(s),
  18         light(l),
  19         radius(1),
  20         depth_bias(4),
  21         rendered(false)
  22 {
  23         depth_buf.set_min_filter(LINEAR);
  24         depth_buf.set_compare_enabled(true);
  25         depth_buf.set_compare_func(LEQUAL);
  26         depth_buf.set_wrap(CLAMP_TO_EDGE);
  27         depth_buf.storage(DEPTH_COMPONENT, size, size);
  28         fbo.attach(DEPTH_ATTACHMENT, depth_buf, 0);
  29         fbo.require_complete();
  30
  31         set_darkness(0.7);
  32 }
  33
  34 void ShadowMap::set_target(const Vector3 &t, float r)
  35 {
  36         target = t;
  37         radius = r;
  38 }
  39
  40 void ShadowMap::set_darkness(float d)
  41 {
  42         if(d<0.0f || d>1.0f)
  43                 throw invalid_argument("ShadowMap::set_darkness");
  44
  45         shdata.uniform("shadow_darkness", d);
  46 }
  47
  48 void ShadowMap::set_depth_bias(float b)
  49 {
  50         if(b<0.0f)
  51                 throw invalid_argument("ShadowMap::set_depth_bias");
  52
  53         depth_bias = b;
  54 }
  55
  56 void ShadowMap::setup_frame(Renderer &renderer)
  57 {
  58         if(rendered)
  59                 return;
  60
  61         rendered = true;
  62         renderable.setup_frame(renderer);
  63
  64         Camera camera;
  65         const Vector4 &lpos = light.get_position();
  66         /* XXX Not really proper way to support positional lights, but good
  67         enough when the light source is far away */
  68         camera.set_look_direction(lpos.w*target-lpos.slice<3>(0));
  69
  70         camera.set_up_direction((abs(camera.get_look_direction().z)<0.99) ? Vector3(0, 0, 1) : Vector3(0, 1, 0));
  71         camera.set_position(target);
  72         camera.set_orthographic(radius*2, radius*2);
  73         camera.set_depth_clip(-radius, radius);
  74
  75         shadow_matrix = camera.get_object_matrix();
  76         shadow_matrix.scale(radius*2, radius*2, -radius*2);
  77         shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
  78         shadow_matrix.invert();
  79
  80         BindRestore bind_fbo(fbo);
  81         Bind bind_depth(DepthTest::lequal());
  82         fbo.clear(DEPTH_BUFFER_BIT);
  83
  84         Renderer::Push push(renderer);
  85         renderer.set_camera(camera);
  86
  87         renderer.render(renderable, "shadow");
  88 }
  89
  90 void ShadowMap::finish_frame()
  91 {
  92         renderable.finish_frame();
  93         rendered = false;
  94 }
  95
  96 void ShadowMap::render(Renderer &renderer, const Tag &tag) const
  97 {
  98         if(!enabled_passes.count(tag))
  99                 return renderer.render(renderable, tag);
 100
 101         Renderer::Push _push_rend(renderer);
 102
 103         unsigned unit = renderer.allocate_effect_texunit();
 104         int iunit = unit;
 105         shdata.uniform("shadow", iunit);
 106
 107         Bind _bind_depth(depth_buf, unit);
 108
 109         if(const Camera *camera = renderer.get_camera())
 110                 /* Multiply by camera's object matrix to form a matrix that transforms
 111                 from eye space to shadow space. */
 112                 shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
 113         else
 114                 shdata.uniform("shd_eye_matrix", shadow_matrix);
 115
 116         renderer.add_shader_data(shdata);
 117         renderer.render(renderable, tag);
 118 }
 119
 120 } // namespace GL
 121 } // namespace Msp