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