From b4582685152d23c4c3b6c7ead4d651c4df06eb01 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@mutantstargoat.com>
Date: Tue, 26 Jul 2016 06:24:42 +0300
Subject: [PATCH] added VR mode with goatvr

---
 Makefile        |    2 +-
 src/app.cc      |  121 +++++++++++++++++++++++++++++++++++++++++++++++++------
 src/backdrop.cc |    2 +-
 3 files changed, 110 insertions(+), 15 deletions(-)

diff --git a/Makefile b/Makefile
index 998cd34..f8a955d 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ warn = -pedantic -Wall
 
 CFLAGS = $(warn) $(opt) $(dbg) $(inc) `pkg-config --cflags sdl2`
 CXXFLAGS = -std=c++11 $(warn) $(opt) $(dbg) $(inc) `pkg-config --cflags sdl2`
-LDFLAGS = $(libgl) -lgmath -limago `pkg-config --libs sdl2`
+LDFLAGS = $(libgl) -lgmath -limago -lgoatvr `pkg-config --libs sdl2`
 
 
 ifeq ($(shell uname -s), Darwin)
diff --git a/src/app.cc b/src/app.cc
index 859e6f2..d8aa144 100644
--- a/src/app.cc
+++ b/src/app.cc
@@ -6,12 +6,19 @@
 #include "mesh.h"
 #include "meshgen.h"
 #include "backdrop.h"
+#include "goatvr.h"
+
+static bool parse_args(int argc, char **argv);
 
 int win_width, win_height;
 float win_aspect;
 long time_msec;
 
+static bool use_vr;
+static bool should_swap;
+
 static float cam_theta, cam_phi;
+static float cam_height = 1.65;
 static Mesh *mesh_torus;
 
 static bool bnstate[16];
@@ -19,6 +26,9 @@ static int prev_x, prev_y;
 
 bool app_init(int argc, char **argv)
 {
+	if(!parse_args(argc, argv)) {
+		return false;
+	}
 	if(init_opengl() == -1) {
 		return false;
 	}
@@ -34,6 +44,21 @@ bool app_init(int argc, char **argv)
 	//glEnable(GL_LIGHTING);
 	glEnable(GL_LIGHT0);
 
+	if(GLEW_ARB_framebuffer_sRGB) {
+		glEnable(GL_FRAMEBUFFER_SRGB);
+	}
+
+	if(use_vr) {
+		if(goatvr_init() == -1) {
+			return false;
+		}
+		goatvr_set_origin_mode(GOATVR_HEAD);
+
+		goatvr_startvr();
+		should_swap = goatvr_should_swap() != 0;
+		cam_height = goatvr_get_eye_height();
+	}
+
 	Mesh::use_custom_sdr_attr = false;
 
 	mesh_torus = new Mesh;
@@ -48,25 +73,59 @@ bool app_init(int argc, char **argv)
 
 void app_cleanup()
 {
+	if(use_vr) {
+		goatvr_shutdown();
+	}
 	delete mesh_torus;
 	cleanup_backdrop();
 }
 
 void app_draw()
 {
-	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	if(use_vr) {
+		// VR mode
+		goatvr_draw_start();
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+		for(int i=0; i<2; i++) {
+			goatvr_draw_eye(i);
+
+			glMatrixMode(GL_PROJECTION);
+			glLoadMatrixf(goatvr_projection_matrix(i, 0.5, 1000.0));
+
+			Mat4 view_mat = goatvr_view_matrix(i);
+			view_mat.pre_rotate_x(deg_to_rad(cam_phi));
+			view_mat.pre_rotate_y(deg_to_rad(cam_theta));
+			view_mat.pre_translate(0, -cam_height, 0);
+
+			glMatrixMode(GL_MODELVIEW);
+			glLoadMatrixf(view_mat[0]);
+
+			draw_backdrop();
+		}
+		goatvr_draw_done();
+
+		if(should_swap) {
+			app_swap_buffers();
+		}
+		app_redraw();	// in VR mode, force continuous redraw
+
+	} else {
+		// regular monoscopic mode
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-	Mat4 view_mat;
-	view_mat.pre_rotate_x(deg_to_rad(cam_phi));
-	view_mat.pre_rotate_y(deg_to_rad(cam_theta));
-	view_mat.pre_translate(0, -1.65, 0);
-	glMatrixMode(GL_MODELVIEW);
-	glLoadMatrixf(view_mat[0]);
+		Mat4 view_mat;
+		view_mat.pre_rotate_x(deg_to_rad(cam_phi));
+		view_mat.pre_rotate_y(deg_to_rad(cam_theta));
+		view_mat.pre_translate(0, -cam_height, 0);
 
-	//mesh_torus->draw();
-	draw_backdrop();
+		glMatrixMode(GL_MODELVIEW);
+		glLoadMatrixf(view_mat[0]);
 
-	app_swap_buffers();
+		draw_backdrop();
+
+		app_swap_buffers();
+	}
 	assert(glGetError() == GL_NO_ERROR);
 }
 
@@ -88,6 +147,12 @@ void app_keyboard(int key, bool pressed)
 		case 27:
 			app_quit();
 			break;
+
+		case ' ':
+			if(use_vr) {
+				goatvr_recenter();
+			}
+			break;
 		}
 	}
 }
@@ -110,10 +175,40 @@ void app_mouse_motion(int x, int y)
 
 	if(bnstate[0]) {
 		cam_theta += dx * 0.5;
-		cam_phi += dy * 0.5;
 
-		if(cam_phi < -90) cam_phi = -90;
-		if(cam_phi > 90) cam_phi = 90;
+		if(!use_vr || !goatvr_have_headtracking()) {
+			cam_phi += dy * 0.5;
+
+			if(cam_phi < -90) cam_phi = -90;
+			if(cam_phi > 90) cam_phi = 90;
+		}
 	}
 	app_redraw();
 }
+
+static bool parse_args(int argc, char **argv)
+{
+	for(int i=1; i<argc; i++) {
+		if(argv[i][0] == '-') {
+			if(strcmp(argv[i], "-vr") == 0) {
+				use_vr = true;
+
+			} else if(strcmp(argv[i], "-novr") == 0) {
+				use_vr = false;
+
+			} else if(strcmp(argv[i], "-help") == 0) {
+				printf("usage: %s [options]\noptions:\n", argv[0]);
+				printf(" -vr/-novr: enable/disable VR\n");
+				printf(" -help: print usage information and exit\n");
+				exit(0);
+			} else {
+				fprintf(stderr, "invalid option: %s\n", argv[i]);
+				return false;
+			}
+		} else {
+			fprintf(stderr, "unexpected option: %s\n", argv[i]);
+			return false;
+		}
+	}
+	return true;
+}
diff --git a/src/backdrop.cc b/src/backdrop.cc
index 33f4c89..f9dbe22 100644
--- a/src/backdrop.cc
+++ b/src/backdrop.cc
@@ -40,7 +40,7 @@ bool init_backdrop()
 	}
 
 	mesh_skydome = new Mesh;
-	gen_sphere(mesh_skydome, 100.0, 32, 16, 1, 0.5);
+	gen_sphere(mesh_skydome, 500.0, 32, 16, 1, 0.5);
 	mesh_skydome->flip();
 
 	return true;
-- 
1.7.10.4