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, 1);
  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         camera.set_object_matrix(*light.get_matrix());
  66         camera.set_position(target);
  67         // TODO support point and spot lights with a frustum projection.
  68         // Omnidirectional lights also need a cube shadow map.
  69         camera.set_orthographic(radius*2, radius*2);
  70         camera.set_depth_clip(-radius, radius);
  71
  72         shadow_matrix = camera.get_object_matrix();
  73         shadow_matrix.scale(radius*2, radius*2, -radius*2);
  74         shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
  75         shadow_matrix.invert();
  76
  77         BindRestore bind_fbo(fbo);
  78         Bind bind_depth(DepthTest::lequal());
  79         fbo.clear(DEPTH_BUFFER_BIT);
  80
  81         Renderer::Push push(renderer);
  82         renderer.set_camera(camera);
  83
  84         renderer.render(renderable, "shadow");
  85 }
  86
  87 void ShadowMap::finish_frame()
  88 {
  89         renderable.finish_frame();
  90         rendered = false;
  91 }
  92
  93 void ShadowMap::render(Renderer &renderer, const Tag &tag) const
  94 {
  95         if(!enabled_passes.count(tag))
  96                 return renderer.render(renderable, tag);
  97
  98         Renderer::Push _push_rend(renderer);
  99
 100         unsigned unit = renderer.allocate_effect_texunit();
 101         int iunit = unit;
 102         shdata.uniform("shadow", iunit);
 103
 104         Bind _bind_depth(depth_buf, unit);
 105
 106         if(const Camera *camera = renderer.get_camera())
 107                 /* Multiply by camera's object matrix to form a matrix that transforms
 108                 from eye space to shadow space. */
 109                 shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
 110         else
 111                 shdata.uniform("shd_eye_matrix", shadow_matrix);
 112
 113         renderer.add_shader_data(shdata);
 114         renderer.render(renderable, tag);
 115 }
 116
 117 } // namespace GL
 118 } // namespace Msp