From 5012c1bd8e58d7c2cfc16b7703e4bca11144b060 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 16 Dec 2013 22:25:49 +0200
Subject: [PATCH] Add shd_eye_matrix to ShadowMap's shdata

---
 source/shadowmap.cpp | 23 ++++++++++++++++-------
 source/shadowmap.h   |  3 ++-
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/source/shadowmap.cpp b/source/shadowmap.cpp
index 737423f7..bd87d262 100644
--- 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"
@@ -108,6 +109,11 @@ 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);
@@ -125,19 +131,22 @@ 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();
-
-	// 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);
 
+	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::Push _push_rend(renderer);
 	renderer.add_shader_data(shdata);
 	renderer.render(renderable, tag);
diff --git a/source/shadowmap.h b/source/shadowmap.h
index 1b9d8f14..4903afeb 100644
--- a/source/shadowmap.h
+++ b/source/shadowmap.h
@@ -27,12 +27,13 @@ private:
 	mutable Framebuffer fbo;
 	mutable Matrix light_matrix;
 	mutable Matrix view_matrix;
+	mutable Matrix shadow_matrix;
 	unsigned unit;
 	Texture2D depth_buf;
 	Vector3 target;
 	float radius;
 	float depth_bias;
-	ProgramData shdata;
+	mutable ProgramData shdata;
 	mutable bool rendered;
 
 public:
-- 
2.43.0