source/effects/shadowmap.cpp

   1 #include <cmath>
   2 #include <cstdlib>
   3 #include "camera.h"
   4 #include "light.h"
   5 #include "renderer.h"
   6 #include "resources.h"
   7 #include "scene.h"
   8 #include "shadowmap.h"
   9 #include "tests.h"
  10
  11 using namespace std;
  12
  13 namespace Msp {
  14 namespace GL {
  15
  16 ShadowMap::ShadowMap(Resources &resources, unsigned s, Renderable &r, const Light &l, Renderable &c):
  17         Effect(r),
  18         light(l),
  19         shadow_caster(c),
  20         sampler(resources.get<Sampler>("_linear_clamp_shadow.samp"))
  21 {
  22         init(s);
  23 }
  24
  25 ShadowMap::ShadowMap(Resources &resources, unsigned s, Renderable &r, const Light &l):
  26         Effect(r),
  27         light(l),
  28         shadow_caster(r),
  29         sampler(resources.get<Sampler>("_linear_clamp_shadow.samp"))
  30 {
  31         init(s);
  32 }
  33
  34 void ShadowMap::init(unsigned s)
  35 {
  36         size = s;
  37         radius = 1;
  38         depth_bias = 4;
  39         rendered = false;
  40
  41         depth_buf.storage(DEPTH_COMPONENT32F, size, size, 1);
  42         fbo.attach(DEPTH_ATTACHMENT, depth_buf, 0);
  43         fbo.require_complete();
  44
  45         set_darkness(0.7);
  46 }
  47
  48 void ShadowMap::set_target(const Vector3 &t, float r)
  49 {
  50         target = t;
  51         radius = r;
  52 }
  53
  54 void ShadowMap::set_darkness(float d)
  55 {
  56         if(d<0.0f || d>1.0f)
  57                 throw invalid_argument("ShadowMap::set_darkness");
  58
  59         shdata.uniform("shadow_darkness", d);
  60 }
  61
  62 void ShadowMap::set_depth_bias(float b)
  63 {
  64         if(b<0.0f)
  65                 throw invalid_argument("ShadowMap::set_depth_bias");
  66
  67         depth_bias = b;
  68 }
  69
  70 void ShadowMap::setup_frame(Renderer &renderer)
  71 {
  72         if(rendered)
  73                 return;
  74
  75         rendered = true;
  76         renderable.setup_frame(renderer);
  77         shadow_caster.setup_frame(renderer);
  78
  79         shadow_camera.set_object_matrix(*light.get_matrix());
  80         shadow_camera.set_position(target);
  81         // TODO support point and spot lights with a frustum projection.
  82         // Omnidirectional lights also need a cube shadow map.
  83         shadow_camera.set_orthographic(radius*2, radius*2);
  84         shadow_camera.set_depth_clip(-radius, radius);
  85
  86         shadow_matrix = shadow_camera.get_object_matrix();
  87         shadow_matrix.scale(radius*2, radius*2, -radius*2);
  88         shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
  89         shadow_matrix.invert();
  90
  91         BindRestore bind_fbo(fbo);
  92         Bind bind_depth(DepthTest::lequal());
  93         fbo.clear(DEPTH_BUFFER_BIT);
  94
  95         Renderer::Push push(renderer);
  96         renderer.set_camera(shadow_camera);
  97
  98         renderer.render(shadow_caster);
  99 }
 100
 101 void ShadowMap::finish_frame()
 102 {
 103         if(rendered)
 104         {
 105                 rendered = false;
 106                 renderable.finish_frame();
 107         }
 108 }
 109
 110 void ShadowMap::render(Renderer &renderer, Tag tag) const
 111 {
 112         if(!enabled_passes.count(tag))
 113                 return renderer.render(renderable, tag);
 114
 115         if(const Camera *camera = renderer.get_camera())
 116                 /* Multiply by camera's object matrix to form a matrix that transforms
 117                 from eye space to shadow space. */
 118                 shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
 119         else
 120                 shdata.uniform("shd_eye_matrix", shadow_matrix);
 121
 122         Renderer::Push _push_rend(renderer);
 123
 124         renderer.set_texture("shadow_map", &depth_buf, &sampler);
 125         renderer.add_shader_data(shdata);
 126         renderer.render(renderable, tag);
 127 }
 128
 129 } // namespace GL
 130 } // namespace Msp