source/shadowmap.cpp

   1 #include <cmath>
   2 #include <cstdlib>
   3 #include "camera.h"
   4 #include "light.h"
   5 #include "matrix.h"
   6 #include "misc.h"
   7 #include "renderer.h"
   8 #include "scene.h"
   9 #include "shadowmap.h"
  10 #include "tests.h"
  11 #include "texgen.h"
  12 #include "texunit.h"
  13
  14 using namespace std;
  15
  16 namespace Msp {
  17 namespace GL {
  18
  19 ShadowMap::ShadowMap(unsigned s, const Renderable &r, const Light &l):
  20         Effect(r),
  21         size(s),
  22         light(l),
  23         radius(1),
  24         depth_bias(4),
  25         rendered(false)
  26 {
  27         depth_buf.set_min_filter(LINEAR);
  28         depth_buf.set_compare_enabled(true);
  29         depth_buf.set_compare_func(LEQUAL);
  30         depth_buf.set_wrap(CLAMP_TO_EDGE);
  31         depth_buf.storage(DEPTH_COMPONENT, size, size);
  32         fbo.attach(DEPTH_ATTACHMENT, depth_buf, 0);
  33         fbo.require_complete();
  34
  35         set_darkness(0.7);
  36         set_texture_unit(3);
  37 }
  38
  39 void ShadowMap::set_target(const Vector3 &t, float r)
  40 {
  41         target = t;
  42         radius = r;
  43 }
  44
  45 void ShadowMap::set_darkness(float d)
  46 {
  47         if(d<0.0f || d>1.0f)
  48                 throw invalid_argument("ShadowMap::set_darkness");
  49
  50         shdata.uniform("shadow_darkness", d);
  51 }
  52
  53 void ShadowMap::set_depth_bias(float b)
  54 {
  55         if(b<0.0f)
  56                 throw invalid_argument("ShadowMap::set_depth_bias");
  57
  58         depth_bias = b;
  59 }
  60
  61 void ShadowMap::set_texture_unit(unsigned u)
  62 {
  63         unit = u;
  64
  65         int i = unit;
  66         shdata.uniform("shadow", i);
  67         shdata.uniform("shadow_unit", i);
  68 }
  69
  70 void ShadowMap::setup_frame() const
  71 {
  72         if(rendered)
  73                 return;
  74
  75         renderable.setup_frame();
  76         rendered = true;
  77
  78         const Vector4 &lpos = light.get_position();
  79         Vector3 back;
  80         if(lpos.w)
  81         {
  82                 /* XXX Not really proper way to support positional lights, but good
  83                 enough when the light source is far away */
  84                 back = Vector3(lpos)-target;
  85         }
  86         else
  87                 back = Vector3(lpos);
  88         back.normalize();
  89
  90         Vector3 up;
  91         if(abs(back.z)<0.99)
  92                 up = Vector3(0, 0, 1);
  93         else
  94                 up = Vector3(0, 1, 0);
  95
  96         Vector3 right = normalize(cross(up, back));
  97
  98         Vector4 columns[4];
  99         columns[0] = Vector4(right, 0.0f);
 100         columns[1] = Vector4(normalize(cross(back, right)), 0.0f);
 101         columns[2] = Vector4(back, 0.0f);
 102         columns[3] = Vector4(target, 1.0f);
 103         light_matrix = Matrix::from_columns(columns);
 104         view_matrix = invert(light_matrix);
 105
 106         MatrixStack::Push push_mv(MatrixStack::modelview());
 107         MatrixStack::Push push_proj(MatrixStack::projection());
 108
 109         MatrixStack::projection() = Matrix::ortho(-radius, radius, -radius, radius, -radius, radius);
 110         MatrixStack::modelview() = view_matrix;
 111
 112         shadow_matrix = light_matrix;
 113         shadow_matrix.scale(radius*2, radius*2, -radius*2);
 114         shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
 115         shadow_matrix.invert();
 116
 117         Bind bind_fbo(fbo, true);
 118         Bind bind_depth(DepthTest::lequal());
 119         fbo.clear(DEPTH_BUFFER_BIT);
 120         renderable.render("shadow");
 121 }
 122
 123 void ShadowMap::finish_frame() const
 124 {
 125         renderable.finish_frame();
 126         rendered = false;
 127 }
 128
 129 void ShadowMap::render(Renderer &renderer, const Tag &tag) const
 130 {
 131         if(!enabled_passes.count(tag))
 132                 return renderer.render(renderable, tag);
 133
 134         depth_buf.bind_to(unit);
 135         TexGen tg_s, tg_t, tg_r;
 136         tg_s.set_plane(Vector4(shadow_matrix(0, 0), shadow_matrix(0, 1), shadow_matrix(0, 2), shadow_matrix(0, 3)));
 137         tg_t.set_plane(Vector4(shadow_matrix(1, 0), shadow_matrix(1, 1), shadow_matrix(1, 2), shadow_matrix(1, 3)));
 138         tg_r.set_plane(Vector4(shadow_matrix(2, 0), shadow_matrix(2, 1), shadow_matrix(2, 2), shadow_matrix(2, 3)));
 139         tg_s.bind_to(unit, SCOORD);
 140         tg_t.bind_to(unit, TCOORD);
 141         tg_r.bind_to(unit, RCOORD);
 142
 143         if(const Camera *camera = renderer.get_camera())
 144                 /* Multiply by camera's object matrix to form a matrix that transforms
 145                 from eye space to shadow space. */
 146                 shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
 147         else
 148                 shdata.uniform("shd_eye_matrix", shadow_matrix);
 149
 150         Renderer::Push _push_rend(renderer);
 151         renderer.add_shader_data(shdata);
 152         renderer.render(renderable, tag);
 153
 154         Texture::unbind_from(unit);
 155         TexGen::unbind_from(unit, SCOORD);
 156         TexGen::unbind_from(unit, TCOORD);
 157         TexGen::unbind_from(unit, RCOORD);
 158 }
 159
 160 } // namespace GL
 161 } // namespace Msp