Automatically determine texture units for effects

[libs/gl.git] / source / shadowmap.cpp

diff --git a/source/shadowmap.cpp b/source/shadowmap.cpp
index 737423f7ff3687fd5e6c95870f2ad854623128c5..8151a7cffe48c41429005470ac3595916fb309e1 100644 (file)
--- a/source/shadowmap.cpp
+++ b/source/shadowmap.cpp
@@ -1,5 +1,6 @@
 #include <cmath>
 #include <cstdlib>
+#include "camera.h"
 #include "light.h"
 #include "matrix.h"
 #include "misc.h"
@@ -32,7 +33,6 @@ ShadowMap::ShadowMap(unsigned s, const Renderable &r, const Light &l):
        fbo.require_complete();
 
        set_darkness(0.7);
-       set_texture_unit(3);
 }
 
 void ShadowMap::set_target(const Vector3 &t, float r)
@@ -57,15 +57,6 @@ void ShadowMap::set_depth_bias(float b)
        depth_bias = b;
 }
 
-void ShadowMap::set_texture_unit(unsigned u)
-{
-       unit = u;
-
-       int i = unit;
-       shdata.uniform("shadow", i);
-       shdata.uniform("shadow_unit", i);
-}
-
 void ShadowMap::setup_frame() const
 {
        if(rendered)
@@ -108,6 +99,11 @@ void ShadowMap::setup_frame() const
        MatrixStack::projection() = Matrix::ortho(-radius, radius, -radius, radius, -radius, radius);
        MatrixStack::modelview() = view_matrix;
 
+       shadow_matrix = light_matrix;
+       shadow_matrix.scale(radius*2, radius*2, -radius*2);
+       shadow_matrix.translate(-0.5, -0.5, depth_bias/size-0.5);
+       shadow_matrix.invert();
+
        Bind bind_fbo(fbo, true);
        Bind bind_depth(DepthTest::lequal());
        fbo.clear(DEPTH_BUFFER_BIT);
@@ -125,20 +121,29 @@ void ShadowMap::render(Renderer &renderer, const Tag &tag) const
        if(!enabled_passes.count(tag))
                return renderer.render(renderable, tag);
 
-       const float *matrix = view_matrix.data();
+       Renderer::Push _push_rend(renderer);
+
+       unsigned unit = renderer.allocate_effect_texunit();
+       int iunit = unit;
+       shdata.uniform("shadow", iunit);
+       shdata.uniform("shadow_unit", iunit);
 
-       // Has side effect of changing the current unit
        depth_buf.bind_to(unit);
-       float diam = radius*2;
        TexGen tg_s, tg_t, tg_r;
-       tg_s.set_plane(Vector4(matrix[0]/diam, matrix[4]/diam, matrix[8]/diam, matrix[12]/diam+0.5f));
-       tg_t.set_plane(Vector4(matrix[1]/diam, matrix[5]/diam, matrix[9]/diam, matrix[13]/diam+0.5f));
-       tg_r.set_plane(Vector4(-matrix[2]/diam, -matrix[6]/diam, -matrix[10]/diam, 0.5f-matrix[14]/diam-depth_bias/size));
+       tg_s.set_plane(Vector4(shadow_matrix(0, 0), shadow_matrix(0, 1), shadow_matrix(0, 2), shadow_matrix(0, 3)));
+       tg_t.set_plane(Vector4(shadow_matrix(1, 0), shadow_matrix(1, 1), shadow_matrix(1, 2), shadow_matrix(1, 3)));
+       tg_r.set_plane(Vector4(shadow_matrix(2, 0), shadow_matrix(2, 1), shadow_matrix(2, 2), shadow_matrix(2, 3)));
        tg_s.bind_to(unit, SCOORD);
        tg_t.bind_to(unit, TCOORD);
        tg_r.bind_to(unit, RCOORD);
 
-       Renderer::Push _push_rend(renderer);
+       if(const Camera *camera = renderer.get_camera())
+               /* Multiply by camera's object matrix to form a matrix that transforms
+               from eye space to shadow space. */
+               shdata.uniform("shd_eye_matrix", shadow_matrix*camera->get_object_matrix());
+       else
+               shdata.uniform("shd_eye_matrix", shadow_matrix);
+
        renderer.add_shader_data(shdata);
        renderer.render(renderable, tag);