[Performous-commit] Lasse Karkkainen : Stereo3d shader cleanup and changed stereo viewport numbering.

[Lasse Kärkkäi. <tr...@us...>]

Author: Lasse Karkkainen <tro...@tr...>
Date:   Mon Feb 28 01:26:21 2011 +0100

Stereo3d shader cleanup and changed stereo viewport numbering.

---

 data/shaders/stereo3d.geom |   42 +++++++++++-------------------------------
 game/video_driver.cc       |    8 ++++----
 2 files changed, 15 insertions(+), 35 deletions(-)

diff --git a/data/shaders/stereo3d.geom b/data/shaders/stereo3d.geom
index b19f19b..4fa2f7a 100644
--- a/data/shaders/stereo3d.geom
+++ b/data/shaders/stereo3d.geom
@@ -1,6 +1,9 @@
 #version 330
 #extension GL_ARB_viewport_array : require
 
+uniform float sepFactor;
+uniform float z0;
+
 layout(triangles) in;
 layout(triangle_strip, max_vertices = 6) out;
 
@@ -12,47 +15,24 @@ out vec4 texCoord;
 out vec3 normal;
 out vec4 color;
 
-uniform float sepFactor;
-uniform float z0;
+int i;
 
-void passthru(in int i) {
+void passthru() {
 	gl_Position = gl_in[i].gl_Position;
 	texCoord = vTexCoord[i];
 	normal = vNormal[i];
 	color = vColor[i];
 }
 
+// Process all the vertices, applying code to them before emitting (do-while to convince Nvidia of the code getting executed)
+#define PROCESS(code) i = 0; do { passthru(); code; EmitVertex(); } while (++i < gl_in.length()); EndPrimitive();
+
 void main() {
-	// Fix Nvidia compile warnings ("might be used uninitialized")
-	gl_Position = vec4(0);
-	texCoord = vec4(0);
-	normal = vec3(0);
-	color = vec4(0);
 	if (sepFactor == 0.0) {
-		// No stereo
-		gl_ViewportIndex = 0;
-		for(int i=0; i < gl_in.length(); ++i) {
-			passthru(i);
-			EmitVertex();
-		}
-		EndPrimitive();
+		gl_ViewportIndex = 0; PROCESS(); // No stereo
 	} else {
-		// Render the left eye
-		gl_ViewportIndex = 0;
-		for(int i=0; i < gl_in.length(); ++i) {
-			passthru(i);
-			gl_Position.x -= sepFactor * (gl_Position.z - z0);
-			EmitVertex();
-		}
-		EndPrimitive();
-		// Render the right eye
-		gl_ViewportIndex = 1;
-		for(int i=0; i < gl_in.length(); ++i) {
-			passthru(i);
-			gl_Position.x += sepFactor * (gl_Position.z - z0);
-			EmitVertex();
-		}
-		EndPrimitive();
+		gl_ViewportIndex = 1; PROCESS(gl_Position.x -= sepFactor * (gl_Position.z - z0));  // Left eye
+		gl_ViewportIndex = 2; PROCESS(gl_Position.x += sepFactor * (gl_Position.z - z0));  // Right eye
 	}
 }
 
diff --git a/game/video_driver.cc b/game/video_driver.cc
index 5a4e9ce..01c712d 100644
--- a/game/video_driver.cc
+++ b/game/video_driver.cc
@@ -178,8 +178,8 @@ void Window::render(boost::function<void (void)> drawFunc) {
 	{
 		UseFBO user(fbo);
 		view(0);
-		glViewportIndexedf(0, 0, h / 2, w, h / 2);
-		glViewportIndexedf(1, 0, 0, w, h / 2);
+		glViewportIndexedf(1, 0, h / 2, w, h / 2);
+		glViewportIndexedf(2, 0, 0, w, h / 2);
 		drawFunc();
 	}
 	glerror.check("Render to FBO");
@@ -240,8 +240,8 @@ void Window::view(unsigned num) {
 	if (num == 0) {
 		glViewport(vx, vy, vw, vh);  // Drawable area of the window (excluding black bars)
 	} else {
-		glViewportIndexedf(0, 0, vh / 2, vw, vh / 2);  // Top half of the drawable area
-		glViewportIndexedf(1, 0, 0, vw, vh / 2);  // Bottom half of the drawable area
+		glViewportIndexedf(1, 0, vh / 2, vw, vh / 2);  // Top half of the drawable area
+		glViewportIndexedf(2, 0, 0, vw, vh / 2);  // Bottom half of the drawable area
 	}
 
 }