# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1379726120 -10800
# Node ID 402cbb6d9ce31a38ad8018251b3e98dae0d0e080
# Parent  cceffea995a46c445bb5aa66e27ad1026b65b506
added the shader as a separate header file

diff -r cceffea995a4 -r 402cbb6d9ce3 src/vr.cc
--- a/src/vr.cc	Sat Sep 21 03:35:53 2013 +0300
+++ b/src/vr.cc	Sat Sep 21 04:15:20 2013 +0300
@@ -2,35 +2,7 @@
 #include <GL/glew.h>
 #include "vr.h"
 #include "vr_impl.h"
-
-static const char *sdr_src =
-	"uniform sampler2D tex;\n"
-	"uniform vec2 lens_center;\n"
-	"uniform vec2 scr_center;\n"
-	"uniform vec2 scale;\n"
-	"uniform vec2 scale_in;\n"
-	"uniform vec4 warp_param;\n"
-	"\n"
-	"vec2 warp(in vec2 pt, out float dbgrad)\n"
-	"{\n"
-	"    vec2 theta = (pt - lens_center) * scale_in;\n"
-	"    float rsq = dot(theta, theta);\n"
-	"    vec2 rvec = theta * (warp_param.x + \n"
-	"                         warp_param.y * rsq +\n"
-	"                         warp_param.z * rsq * rsq +\n"
-	"                         warp_param.w * rsq * rsq * rsq);\n"
-	"    dbgrad = length(theta);\n"
-	"    return lens_center + scale * rvec;\n"
-	"}\n"
-	"\n"
-	"void main()\n"
-	"{\n"
-	"    float dbgrad;\n"
-	"    vec2 tc = warp(gl_TexCoord[0].xy, dbgrad);\n"
-	"    gl_FragColor.rgb = texture2D(tex, tc).rgb;\n"
-	"    gl_FragColor.rgb += mix(vec3(1.0, 1.0, 0.0), vec3(0.0), smoothstep(0.01, 0.05, dbgrad));\n"
-	"    gl_FragColor.a = 1.0;\n"
-	"}\n";
+#include "vr_sdr.h"
 
 static bool init_ovr();
 static bool init_sdr();
@@ -55,6 +27,7 @@
 
 extern "C" void vr_shutdown(void)
 {
+	delete [] vr_ctx.info.display;
 	//System::Destroy();
 }
 
@@ -124,6 +97,10 @@
 		float center_dist_meters = info.HScreenSize * 0.25;
 		float proj_shift = center_dist_meters - info.LensSeparationDistance * 0.5;
 		vr_ctx.info.proj_center_offset = 4.0 * proj_shift / info.HScreenSize;
+
+		// grab the display name
+		vr_ctx.info.display = new char[strlen(info.DisplayDeviceName) + 1];
+		strcpy(vr_ctx.info.display, info.DisplayDeviceName);
 	}
 
 	// get the sensor device
diff -r cceffea995a4 -r 402cbb6d9ce3 src/vr_impl.h
--- a/src/vr_impl.h	Sat Sep 21 03:35:53 2013 +0300
+++ b/src/vr_impl.h	Sat Sep 21 04:15:20 2013 +0300
@@ -12,6 +12,7 @@
 	SensorFusion ovr_sfusion;
 
 	struct {
+		char *display;
 		// the full width and height of the display (both eyes)
 		int width, height;
 		float fov;
diff -r cceffea995a4 -r 402cbb6d9ce3 src/vr_sdr.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/vr_sdr.h	Sat Sep 21 04:15:20 2013 +0300
@@ -0,0 +1,45 @@
+static const char *sdr_src =
+	"uniform sampler2D tex;\n"
+	"uniform float aspect, scale;\n"
+	"uniform float lens_center_offset;\n"
+	"uniform vec4 dist_factors;\n"
+	"\n"
+	"vec2 distort_texcoords(in vec2 tc);\n"
+	"float barrel_scale(float x, in vec4 k);\n"
+	"\n"
+	"void main()\n"
+	"{\n"
+	"	vec2 tc = distort_texcoords(gl_TexCoord[0].xy);\n"
+	"\n"
+	"	float vis = any(greaterThan(tc, vec2(1.0)) || lessThan(tc, vec2(0.0))) ? 0.0 : 1.0;\n"
+	"\n"
+	"	gl_FragColor.rgb = texture2D(tex, tc).rgb * vis;\n"
+	"	gl_FragColor.a = 1.0;\n"
+	"}\n"
+	"\n"
+	"vec2 distort_texcoords(in vec2 tc)\n"
+	"{\n"
+	"	// map tc [0, 1] -> [-1, 1]\n"
+	"	vec2 pt = tc * 2.0 - 1.0;\n"
+	"\n"
+	"	pt.x += lens_center_offset * 2.0;\n"
+	"	pt.y /= aspect;	// correct for aspect ratio\n"
+	"\n"
+	"	float rad = barrel_scale(dot(pt, pt), dist_factors);\n"
+	"	pt *= rad;	// scale the point by the computer distortion radius\n"
+	"\n"
+	"	pt /= scale;\n"
+	"	pt.y *= aspect;\n"
+	"	pt.x -= lens_center_offset * 2.0;\n"
+	"\n"
+	"	// map back to range [0, 1]\n"
+	"	return pt * 0.5 + 0.5;\n"
+	"}\n"
+	"\n"
+	"float barrel_scale(float rad, in vec4 k)\n"
+	"{\n"
+	"	float radsq = rad * rad;\n"
+	"	float radquad = radsq * radsq;\n"
+	"	return k.x + k.y * radsq + k.z * radquad + k.w * radquad * radsq;\n"
+	"}\n";
+