# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1333492653 -10800
# Node ID 0c3874aa717ac7eac7acc30a7915125b0e962107
# Parent  3e53a16d4667f37ff4a71ea808084ef27bc52af5
slice

diff -r 3e53a16d4667 -r 0c3874aa717a src/volray.c
--- a/src/volray.c	Mon Apr 02 17:59:46 2012 +0300
+++ b/src/volray.c	Wed Apr 04 01:37:33 2012 +0300
@@ -20,9 +20,16 @@
 	struct slice_file *next;
 };
 
+enum {
+	UIMODE_DEFAULT,
+	UIMODE_XFER,
+	UIMODE_CURSOR
+};
+
 int init(void);
 void disp(void);
 void render_volume(void);
+void draw_slice(void);
 void draw_xfer_func(void);
 void reshape(int x, int y);
 void keyb(unsigned char key, int x, int y);
@@ -42,7 +49,7 @@
 vec2_t tex_scale;
 struct slice_file *flist;
 int nslices;
-unsigned int sdr, vol_tex, ray_tex;
+unsigned int vol_sdr, slice_sdr, vol_tex, ray_tex;
 int win_xsz, win_ysz;
 int raytex_needs_recalc = 1;
 
@@ -50,7 +57,8 @@
 float xfer_mean = 0.5, xfer_sdev = 1.0;
 int xfertex_needs_recalc = 1;
 
-static int uimode_xfer;
+static int uimode;
+static float cur_z = 0.5;
 
 int main(int argc, char **argv)
 {
@@ -85,12 +93,18 @@
 {
 	int i, vol_xsz, vol_ysz;
 
-	if(!(sdr = create_program_load("volray.v.glsl", "volray.p.glsl"))) {
+	if(!(vol_sdr = create_program_load("volray.v.glsl", "volray.p.glsl"))) {
 		return -1;
 	}
-	set_uniform_int(sdr, "volume", 0);
-	set_uniform_int(sdr, "ray_tex", 1);
-	set_uniform_int(sdr, "xfer_tex", 2);
+	set_uniform_int(vol_sdr, "volume", 0);
+	set_uniform_int(vol_sdr, "ray_tex", 1);
+	set_uniform_int(vol_sdr, "xfer_tex", 2);
+
+	if(!(slice_sdr = create_program_load(0, "slice.p.glsl"))) {
+		return -1;
+	}
+	set_uniform_int(slice_sdr, "volume", 0);
+	set_uniform_int(slice_sdr, "xfer_tex", 1);
 
 	glGenTextures(1, &vol_tex);
 	glBindTexture(GL_TEXTURE_3D, vol_tex);
@@ -146,6 +160,7 @@
 	}
 
 	render_volume();
+	draw_slice();
 	draw_xfer_func();
 
 	glutSwapBuffers();
@@ -185,7 +200,7 @@
 	glBindTexture(GL_TEXTURE_1D, xfer_tex);
 	glEnable(GL_TEXTURE_1D);
 
-	bind_program(sdr);
+	bind_program(vol_sdr);
 	glBegin(GL_QUADS);
 	glColor3f(1, 1, 1);
 	glTexCoord2f(0, 1); glVertex2f(-1, -1);
@@ -208,6 +223,41 @@
 	glPopMatrix();
 }
 
+void draw_slice(void)
+{
+	glMatrixMode(GL_MODELVIEW);
+	glPushMatrix();
+	glTranslatef(0.9, 0.9, 0);
+	glScalef(0.3, 0.3 * ((float)win_xsz / win_ysz), 1);
+	glTranslatef(-1, -1, 0);
+
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_3D, vol_tex);
+	glEnable(GL_TEXTURE_3D);
+
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_1D, xfer_tex);
+	glEnable(GL_TEXTURE_1D);
+
+	bind_program(slice_sdr);
+
+	glBegin(GL_QUADS);
+	glColor3f(1, 1, 1);
+	glTexCoord3f(0, 1, cur_z); glVertex2f(-1, -1);
+	glTexCoord3f(1, 1, cur_z); glVertex2f(1, -1);
+	glTexCoord3f(1, 0, cur_z); glVertex2f(1, 1);
+	glTexCoord3f(0, 0, cur_z); glVertex2f(-1, 1);
+	glEnd();
+
+	bind_program(0);
+
+	glActiveTexture(GL_TEXTURE1);
+	glDisable(GL_TEXTURE_1D);
+	glActiveTexture(GL_TEXTURE0);
+	glDisable(GL_TEXTURE_3D);
+	glPopMatrix();
+}
+
 void draw_xfer_func(void)
 {
 	glMatrixMode(GL_MODELVIEW);
@@ -232,7 +282,11 @@
 
 	glLineWidth(2.0);
 	glBegin(GL_LINE_LOOP);
-	glColor3f(uimode_xfer ? 1 : 0, 0, uimode_xfer ? 0 : 1);
+	if(uimode == UIMODE_XFER) {
+		glColor3f(1, 0, 0);
+	} else {
+		glColor3f(0, 0, 1);
+	}
 	glVertex2f(0, 0);
 	glVertex2f(1, 0);
 	glVertex2f(1, 1);
@@ -260,9 +314,17 @@
 		exit(0);
 
 	case 'x':
-		uimode_xfer = 1;
+		uimode = UIMODE_XFER;
 		glutPostRedisplay();
 		break;
+
+	case 'c':
+		uimode = UIMODE_CURSOR;
+		glutPostRedisplay();
+		break;
+
+	default:
+		break;
 	}
 }
 
@@ -270,8 +332,20 @@
 {
 	switch(key) {
 	case 'x':
-		uimode_xfer = 0;
-		glutPostRedisplay();
+		if(uimode == UIMODE_XFER) {
+			uimode = UIMODE_DEFAULT;
+			glutPostRedisplay();
+		}
+		break;
+
+	case 'c':
+		if(uimode == UIMODE_CURSOR) {
+			uimode = UIMODE_DEFAULT;
+			glutPostRedisplay();
+		}
+		break;
+
+	default:
 		break;
 	}
 }
@@ -293,7 +367,8 @@
 	prev_x = x;
 	prev_y = y;
 
-	if(uimode_xfer) {
+	switch(uimode) {
+	case UIMODE_XFER:
 		if(dx || dy) {
 			xfer_mean += dx / (float)win_xsz;
 			xfer_sdev += 0.5 * dy / (float)win_ysz;
@@ -304,8 +379,20 @@
 			xfertex_needs_recalc = 1;
 			glutPostRedisplay();
 		}
-	} else {
+		break;
 
+	case UIMODE_CURSOR:
+		cur_z += 0.5 * dy / (float)win_ysz;
+
+		if(cur_z < 0.0)
+			cur_z = 0.0;
+		if(cur_z > 1.0)
+			cur_z = 1.0;
+		glutPostRedisplay();
+		break;
+
+	default:
+		/* view control */
 		if(bnstate[0]) {
 			cam_theta += dx * 0.5;
 			cam_phi += dy * 0.5;
diff -r 3e53a16d4667 -r 0c3874aa717a volray.p.glsl
--- a/volray.p.glsl	Mon Apr 02 17:59:46 2012 +0300
+++ b/volray.p.glsl	Wed Apr 04 01:37:33 2012 +0300
@@ -21,19 +21,19 @@
 vec3 ray_march(Ray ray);
 vec3 shade(Ray ray, ISect isect);
 Ray get_primary_ray();
-bool intersect_aabb(Ray ray, AABBox aabb, out float t);
+ISect intersect_aabb(Ray ray, AABBox aabb);
 
 void main()
 {
-	const AABBox aabb = AABBox(vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));
+	const AABBox aabb = AABBox(vec3(-1.0, -1.0, -1.0), vec3(1.0, 1.0, 1.0));
 	Ray ray = get_primary_ray();
 
 	vec3 color = vec3(0.0, 0.0, 0.0);
 
-	float start_t;
-	if(intersect_aabb(ray, aabb, start_t)) {
-		ray.origin += ray.dir * start_t;
-		color = vec3(1.0, 0.0, 0.0);//ray_march(ray);
+	ISect res = intersect_aabb(ray, aabb);
+	if(res.hit) {
+		ray.origin += ray.dir * res.t;
+		color = ray_march(ray);
 	}
 
 	gl_FragColor = vec4(color, 1.0);
@@ -50,7 +50,8 @@
 
 float eval(vec3 pos)
 {
-	return texture1D(xfer_tex, texture3D(volume, pos).x).x;
+	vec3 tc = pos * 0.5 + 0.5;
+	return texture1D(xfer_tex, texture3D(volume, tc).x).x;
 }
 
 vec3 ray_march(Ray ray)
@@ -97,11 +98,16 @@
 	return ray;
 }
 
-bool intersect_aabb(Ray ray, AABBox aabb, out float t)
+ISect intersect_aabb(Ray ray, AABBox aabb)
 {
+	ISect res;
+	res.hit = false;
+
 	if(ray.origin.x >= aabb.min.x && ray.origin.y >= aabb.min.y && ray.origin.z >= aabb.min.z &&
 			ray.origin.x < aabb.max.x && ray.origin.y < aabb.max.y && ray.origin.z < aabb.max.z) {
-		return true;
+		res.t = 0.0;
+		res.hit = true;
+		return res;
 	}
 
 	vec4 bbox[2];
@@ -119,7 +125,7 @@
 	float tymax = (bbox[1 - ysign].y - ray.origin.y) * invdiry;
 
 	if(tmin > tymax || tymin > tmax) {
-		return false;
+		return res;
 	}
 
 	if(tymin > tmin) tmin = tymin;
@@ -131,10 +137,31 @@
 	float tzmax = (bbox[1 - zsign].z - ray.origin.z) * invdirz;
 
 	if(tmin > tzmax || tzmin > tmax) {
-		return false;
+		return res;
 	}
 
-	t = tmin;
-	return tmin < 1.0 && tmax > 0.0;
+	res.t = tmin;
+	res.hit = true;
+	res.pos = ray.origin + ray.dir * res.t;
+
+	/*if(res.pos.x > res.pos.y && res.pos.x > res.pos.z) {
+		res.normal = vec3(1.0, 0.0, 0.0);
+	} else if(res.pos.x < res.pos.y && res.pos.x < res.pos.z) {
+		res.normal = vec3(-1.0, 0.0, 0.0);
+	} else if(res.pos.y > res.pos.x && res.pos.y > res.pos.z) {
+		res.normal = vec3(0.0, 1.0, 0.0);
+	} else if(res.pos.y < res.pos.x && res.pos.y < res.pos.z) {
+		res.normal = vec3(0.0, -1.0, 0.0);
+	} else if(res.pos.z > res.pos.x && res.pos.z > res.pos.y) {
+		res.normal = vec3(0.0, 0.0, 1.0);
+	} else {
+		res.normal = vec3(0.0, 0.9, -1.0);
+	}
+	if(res.pos.x < 0.0) {
+		res.normal = vec3(1.0, 0.0, 0.0);
+	} else {
+		res.normal = vec3(0.0, 0.0, 1.0);
+	}*/
+	return res;
 }