[Performous-commit] Lasse Karkkainen : Proper calculation of frustum instead of arbitrary multiplier

[Lasse Kärkkäi. <tr...@us...>]

Module: performous
Branch: opengl2
Commit: 7f57f0db64a7cfe6040a5a5d31c64026ca122150

Author: Lasse Karkkainen <tro...@tr...>
Date:   Mon Jan 24 00:45:07 2011 +0100

Proper calculation of frustum instead of arbitrary multiplier

---

 game/video_driver.cc |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/game/video_driver.cc b/game/video_driver.cc
index c501639..97da558 100644
--- a/game/video_driver.cc
+++ b/game/video_driver.cc
@@ -142,14 +142,15 @@ void Window::resize() {
 	glLoadIdentity();
 	float h = virtH();
 	// stump: under MSVC, near and far are #defined to nothing for compatibility with ancient code, hence the underscores.
-	const float near_ = 1.5f; // This determines FOV: the value is your distance from the monitor (the unit being the width of the Performous window)
+	const float near_ = 0.5f; // This determines the near clipping distance (must be > 0)
 	const float far_ = 100.0f; // How far away can things be seen
+	const float z0 = 1.5f; // This determines FOV: the value is your distance from the monitor (the unit being the width of the Performous window)
 	// Set model-view matrix
 	glMatrixMode(GL_MODELVIEW);
 	glLoadIdentity();
-	const float f = 0.9f; // Avoid texture surface being exactly at the near plane (MacOSX fix)
-	glFrustum(-0.5f * f, 0.5f * f, 0.5f * h * f, -0.5f * h * f, f * near_, far_);
-	glTranslatef(0.0f, 0.0f, -near_);  // So that z = 0.0f is still on monitor surface
+	const float f = near_ / z0;
+	glFrustum(-0.5f * f, 0.5f * f, 0.5f * h * f, -0.5f * h * f, near_, far_);
+	glTranslatef(0.0f, 0.0f, -z0);  // Move back the world so that z = 0.0f is the monitor surface
 	// Check for OpenGL errors
 	glutil::GLErrorChecker glerror("Window::resize");
 }