From 7c9f96e426d0a745abd11665f66b6778ca6462f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Benjamin=20=E2=80=98Touky=E2=80=99=20Huet?=
 <huet.benjamin@gmail.com>
Date: Sun, 16 Feb 2014 19:28:07 +0000
Subject: [PATCH] Added Debug::DrawViewProj

---
 src/debug/lines.cpp   | 57 ++++++++++++++++++++++++++++++++++++++++---
 src/lol/debug/lines.h |  2 ++
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/src/debug/lines.cpp b/src/debug/lines.cpp
index 982a294f..a725e119 100644
--- a/src/debug/lines.cpp
+++ b/src/debug/lines.cpp
@@ -36,11 +36,62 @@ void Debug::DrawBox(vec3 a, vec3 b, vec4 color)
     {
         int j = ((i & 1) << 1) | ((i >> 1) ^ 1);
 
-        g_scene->AddLine(v[i], v[i + 4], color);
-        g_scene->AddLine(v[i], v[j], color);
-        g_scene->AddLine(v[i + 4], v[j + 4], color);
+        Debug::DrawLine(v[i], v[i + 4], color);
+        Debug::DrawLine(v[i], v[j], color);
+        Debug::DrawLine(v[i + 4], v[j + 4], color);
     }
 }
 
+void Debug::DrawViewProj(mat4 view, mat4 proj, vec4 color)
+{
+     mat4 view_proj = proj * view;
+
+     //Pos to center
+    vec3 p0 = (inverse(view) * vec4(vec3::zero, 1.f)).xyz;
+
+    //Near plane
+    vec4 p[4] = { inverse(view_proj) * vec4(-1.f, 1.f, -1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f, 1.f, -1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f,-1.f, -1.f, 1.f),
+                  inverse(view_proj) * vec4(-1.f,-1.f, -1.f, 1.f) };
+    for (int i = 0; i < 4; i++)
+        p[i] = p[i] / p[i].w;
+
+    //Draw near
+    for (int i = 0; i < 4; i++)
+        Debug::DrawLine(p[i].xyz, p0, color);
+
+    Debug::DrawViewProj(view_proj, color);
+}
+
+void Debug::DrawViewProj(mat4 view_proj, vec4 color)
+{
+    //Near plane
+    vec4 p[8] = { inverse(view_proj) * vec4(-1.f, 1.f, 1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f, 1.f, 1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f,-1.f, 1.f, 1.f),
+                  inverse(view_proj) * vec4(-1.f,-1.f, 1.f, 1.f),
+                  inverse(view_proj) * vec4(-1.f, 1.f,-1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f, 1.f,-1.f, 1.f),
+                  inverse(view_proj) * vec4( 1.f,-1.f,-1.f, 1.f),
+                  inverse(view_proj) * vec4(-1.f,-1.f,-1.f, 1.f)
+                };
+    for (int i = 0; i < 8; i++)
+        p[i] = p[i] / p[i].w;
+
+    //Draw near
+    for (int i = 0; i < 4; i++)
+        Debug::DrawLine(p[i].xyz, p[(i + 1) % 4].xyz, color);
+    //Draw far
+    for (int i = 4; i < 8; i++)
+        Debug::DrawLine(p[i].xyz, p[(i - 4 + 1) % 4 + 4].xyz, color);
+    //Draw near to far
+    for (int i = 0; i < 4; i++)
+        Debug::DrawLine(p[i].xyz, p[i + 4].xyz, color);
+    //Draw diagonal
+    for (int i = 2; i < 6; i++)
+        Debug::DrawLine(p[i].xyz, p[i + ((i < 4)?(-2):(+2))].xyz, color);
+}
+
 } /* namespace lol */
 
diff --git a/src/lol/debug/lines.h b/src/lol/debug/lines.h
index bd47a3eb..cb182e76 100644
--- a/src/lol/debug/lines.h
+++ b/src/lol/debug/lines.h
@@ -26,6 +26,8 @@ namespace Debug
 
 void DrawLine(vec3 a, vec3 b, vec4 color);
 void DrawBox(vec3 a, vec3 b, vec4 color);
+void DrawViewProj(mat4 view_proj, vec4 color);
+void DrawViewProj(mat4 view, mat4 proj, vec4 color);
 
 } /* namespace Debug */