source/effects/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 WeakPtr<Sampler> ShadowMap::shadow_sampler;
  16
  17 ShadowMap::ShadowMap(unsigned s, Renderable &r, const Light &l):
  18         Effect(r),
  19         size(s),
  20         light(l),
  21         radius(1),
  22         depth_bias(4),
  23         rendered(false)
  24 {
  25         sampler = shadow_sampler;
  26         if(!sampler)
  27         {
  28                 sampler = new Sampler;
  29                 sampler->set_filter(LINEAR);
  30                 sampler->set_compare(LEQUAL);
  31                 sampler->set_wrap(CLAMP_TO_EDGE);
  32                 shadow_sampler = sampler;
  33         }
  34         depth_buf.storage(DEPTH_COMPONENT32F, size, size, 1);
  35         fbo.attach(DEPTH_ATTACHMENT, depth_buf, 0);
  36         fbo.require_complete();
  37
  38         set_darkness(0.7);
  39 }
  40
  41 void ShadowMap::set_target(const Vector3 &t, float r)
  42 {
  43         target = t;
  44         radius = r;
  45 }
  46
  47 void ShadowMap::set_darkness(float d)
  48 {
  49         if(d<0.0f || d>1.0f)
  50                 throw invalid_argument("ShadowMap::set_darkness");
  51
  52         shdata.uniform("shadow_darkness", d);
  53 }
  54
  55 void ShadowMap::set_depth_bias(float b)
  56 {
  57         if(b<0.0f)
  58                 throw invalid_argument("ShadowMap::set_depth_bias");
  59
  60         depth_bias = b;
  61 }
  62
  63 void ShadowMap::setup_frame(Renderer &renderer)
  64 {
  65         if(rendered)
  66                 return;
  67
  68         rendered = true;
  69         renderable.setup_frame(renderer);
  70
  71         Camera camera;
  72         camera.set_object_matrix(*light.get_matrix());
  73         camera.set_position(target);
  74         // TODO support point and spot lights with a frustum projection.
  75         // Omnidirectional lights also need a cube shadow map.
  76         camera.set_orthographic(radius*2, radius*2);
  77         camera.set_depth_clip(-radius, radius);
  78
  79         shadow_matrix = camera.get_object_matrix();
  80         shadow_matrix.scale(radius*2, radius*2, -radius*2);
  81         shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
  82         shadow_matrix.invert();
  83
  84         BindRestore bind_fbo(fbo);
  85         Bind bind_depth(DepthTest::lequal());
  86         fbo.clear(DEPTH_BUFFER_BIT);
  87
  88         Renderer::Push push(renderer);
  89         renderer.set_camera(camera);
  90
  91         renderer.render(renderable, "shadow");
  92 }
  93
  94 void ShadowMap::finish_frame()
  95 {
  96         renderable.finish_frame();
  97         rendered = false;
  98 }
  99
 100 void ShadowMap::render(Renderer &renderer, const Tag &tag) const
 101 {
 102         if(!enabled_passes.count(tag))
 103                 return renderer.render(renderable, tag);
 104
 105         Renderer::Push _push_rend(renderer);
 106
 107         unsigned unit = renderer.allocate_effect_texunit();
 108         int iunit = unit;
 109         shdata.uniform("shadow_map", iunit);
 110
 111         Bind _bind_sampler(*sampler, unit);
 112         Bind _bind_depth(depth_buf, unit);
 113
 114         if(const Camera *camera = renderer.get_camera())
 115                 /* Multiply by camera's object matrix to form a matrix that transforms
 116                 from eye space to shadow space. */
 117                 shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
 118         else
 119                 shdata.uniform("shd_eye_matrix", shadow_matrix);
 120
 121         renderer.add_shader_data(shdata);
 122         renderer.render(renderable, tag);
 123 }
 124
 125 } // namespace GL
 126 } // namespace Msp