Add a hackish support for positional lights in ShadowMap

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

diff --git a/source/shadowmap.cpp b/source/shadowmap.cpp
index 9b27ba08d5a5f9e7fff423a1544aaafe827c9018..9dadb8fe16ee4991eda732ceb0219373d8267bfe 100644 (file)
--- a/source/shadowmap.cpp
+++ b/source/shadowmap.cpp
@@ -24,6 +24,7 @@ ShadowMap::ShadowMap(unsigned s, const Scene &c, const Light &l):
        size(s),
        scene(c),
        light(l),
+       unit(3),
        radius(1)
 {
        depth_buf.set_min_filter(LINEAR);
@@ -35,7 +36,7 @@ ShadowMap::ShadowMap(unsigned s, const Scene &c, const Light &l):
        depth_buf.parameter(GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        depth_buf.parameter(GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        fbo.attach(DEPTH_ATTACHMENT, depth_buf, 0);
-       glDrawBuffer(GL_NONE);
+       draw_buffer(NO_BUFFER);
        Framebuffer::unbind();
        Texture::unbind();
 }
@@ -46,11 +47,26 @@ void ShadowMap::set_target(const Vector3 &t, float r)
        radius=r;
 }
 
+void ShadowMap::set_texture_unit(unsigned u)
+{
+       unit=u;
+}
+
 void ShadowMap::prepare()
 {
-       const Vector4 &lpos=light.get_position();
+       Vector4 lpos=light.get_position();
        if(lpos.w)
-               throw Exception("Non-directional lights not supported at the moment");
+       {
+               /* XXX Not really proper way to support positional lights, but good
+               enough when the light source is far away */
+               lpos.x-=target.x;
+               lpos.y-=target.y;
+               lpos.z-=target.z;
+               float d=sqrt(lpos.x*lpos.x+lpos.y*lpos.y+lpos.z*lpos.z);
+               lpos.x/=d;
+               lpos.y/=d;
+               lpos.z/=d;
+       }
 
        float matrix[16];
        if(abs(lpos.z)>=abs(lpos.x) && abs(lpos.z)>=abs(lpos.y))
@@ -95,18 +111,22 @@ void ShadowMap::prepare()
                push_matrix();
                load_matrix(matrix);
 
-               Bind _bind_fbo(fbo);
-               glViewport(0, 0, size, size);
-               glClear(GL_DEPTH_BUFFER_BIT);
-               scene.render();
+               const Framebuffer *old_fbo=Framebuffer::current();
+               fbo.bind();
+               clear(DEPTH_BUFFER_BIT);
+               scene.render("shadow");
 
                matrix_mode(PROJECTION);
                pop_matrix();
                matrix_mode(MODELVIEW);
                pop_matrix();
+               if(old_fbo)
+                       old_fbo->bind();
+               else
+                       Framebuffer::unbind();
        }
 
-       depth_buf.bind_to(3);
+       depth_buf.bind_to(unit);
        float diam=radius*2;
        float s_eq[4]={ matrix[0]/diam, matrix[4]/diam, matrix[8]/diam, matrix[12]/diam+0.5 };
        float t_eq[4]={ matrix[1]/diam, matrix[5]/diam, matrix[9]/diam, matrix[13]/diam+0.5 };
@@ -126,7 +146,7 @@ void ShadowMap::prepare()
 
 void ShadowMap::cleanup()
 {
-       TexUnit::activate(3);
+       TexUnit::activate(unit);
        Texture::unbind();
        disable(GL_TEXTURE_GEN_S);
        disable(GL_TEXTURE_GEN_T);