# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1333321895 -10800
# Node ID 57072295eb83568b84f7f2742a9ddb37b4927110
# Parent  b050ce167ff1805a55ba347cfdf80d61b586189d
progress

diff -r b050ce167ff1 -r 57072295eb83 src/volray.c
--- a/src/volray.c	Sat Mar 31 02:08:42 2012 +0300
+++ b/src/volray.c	Mon Apr 02 02:11:35 2012 +0300
@@ -26,7 +26,7 @@
 void motion(int x, int y);
 int parse_args(int argc, char **argv);
 
-unsigned int create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale);
+static void create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale);
 static vec3_t get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
 static int round_pow2(int x);
 
@@ -38,6 +38,7 @@
 int nslices;
 unsigned int sdr, vol_tex, ray_tex;
 int win_xsz, win_ysz;
+int raytex_needs_recalc = 1;
 
 int main(int argc, char **argv)
 {
@@ -72,16 +73,18 @@
 	int i, vol_xsz, vol_ysz;
 
 	if(!(sdr = create_program_load("volray.v.glsl", "volray.p.glsl"))) {
-		return 1;
+		return -1;
 	}
+	set_uniform_int(sdr, "volume", 0);
+	set_uniform_int(sdr, "ray_tex", 1);
 
 	glGenTextures(1, &vol_tex);
 	glBindTexture(GL_TEXTURE_3D, vol_tex);
 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP);
 
 	for(i=0; i<nslices; i++) {
 		int xsz, ysz;
@@ -114,51 +117,52 @@
 		glTexSubImage3D(GL_TEXTURE_3D, 0, 0, 0, i, xsz, ysz, 1, GL_RGBA, GL_UNSIGNED_BYTE, pix);
 		img_free_pixels(pix);
 	}
-
 	return 0;
 }
 
 void disp(void)
 {
+	if(raytex_needs_recalc) {
+		create_ray_texture(win_xsz, win_ysz, 50.0, &tex_scale);
+	}
+
 	glMatrixMode(GL_MODELVIEW);
 	glLoadIdentity();
+	glRotatef(-90, 1, 0, 0);
 	glTranslatef(cam_x, cam_y, -cam_z);
 	glRotatef(cam_theta, 0, 1, 0);
 	glRotatef(cam_phi, 1, 0, 0);
 	glTranslatef(0, 0, -cam_dist);
 
 	glMatrixMode(GL_TEXTURE);
-	glPushMatrix();
+	glLoadIdentity();
 	glScalef(tex_scale.x, tex_scale.y, 1.0);
 
 	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_3D, vol_tex);
 	glEnable(GL_TEXTURE_3D);
-	glBindTexture(GL_TEXTURE_3D, vol_tex);
 
 	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_2D, ray_tex);
 	glEnable(GL_TEXTURE_2D);
-	glBindTexture(GL_TEXTURE_2D, ray_tex);
 
 	bind_program(sdr);
 	glBegin(GL_QUADS);
 	glColor3f(1, 1, 1);
-	glTexCoord2f(0, 1);
-	glVertex2f(-1, -1);
-	glTexCoord2f(1, 1);
-	glVertex2f(1, -1);
-	glTexCoord2f(1, 0);
-	glVertex2f(1, 1);
-	glTexCoord2f(0, 0);
-	glVertex2f(-1, 1);
+	glTexCoord2f(0, 1); glVertex2f(-1, -1);
+	glTexCoord2f(1, 1); glVertex2f(1, -1);
+	glTexCoord2f(1, 0); glVertex2f(1, 1);
+	glTexCoord2f(0, 0); glVertex2f(-1, 1);
 	glEnd();
 	bind_program(0);
 
+	glActiveTexture(GL_TEXTURE1);
 	glDisable(GL_TEXTURE_2D);
 	glActiveTexture(GL_TEXTURE0);
 	glDisable(GL_TEXTURE_3D);
 
 	glMatrixMode(GL_TEXTURE);
-	glPopMatrix();
+	glLoadIdentity();
 
 	glutSwapBuffers();
 	assert(glGetError() == GL_NO_ERROR);
@@ -166,10 +170,11 @@
 
 void reshape(int x, int y)
 {
+	printf("reshape: %dx%d\n", x, y);
 	glViewport(0, 0, x, y);
 
 	if(x != win_xsz || y != win_ysz) {
-		ray_tex = create_ray_texture(x, y, 50.0, &tex_scale);
+		raytex_needs_recalc = 1;
 		win_xsz = x;
 		win_ysz = y;
 	}
@@ -205,19 +210,20 @@
 		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(cam_phi <= -90) cam_phi = -89;
+		if(cam_phi >= 90) cam_phi = 89;
 
 		glutPostRedisplay();
 	}
 
 	if(bnstate[1]) {
-		cam_y += dy * 0.1;
+		cam_x += dx * 0.025;
+		cam_y += dy * 0.025;
 		glutPostRedisplay();
 	}
 
 	if(bnstate[2]) {
-		cam_dist += dy * 0.1;
+		cam_dist += dy * 0.025;
 		if(cam_dist < 0.0) cam_dist = 0.0;
 		glutPostRedisplay();
 	}
@@ -257,49 +263,52 @@
 }
 
 
-unsigned int create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale)
+static void create_ray_texture(int xsz, int ysz, float vfov, vec2_t *tex_scale)
 {
 	int i, j;
-	unsigned int tex;
+	int cur_tex_xsz, cur_tex_ysz;
 	int tex_xsz = round_pow2(xsz);
 	int tex_ysz = round_pow2(ysz);
 	float *teximg, *dir;
 
-	if(!(teximg = malloc(3 * tex_xsz * tex_ysz * sizeof *teximg))) {
-		return 0;
+	if(!(teximg = malloc(3 * xsz * ysz * sizeof *teximg))) {
+		return;
 	}
 	dir = teximg;
 
-	for(i=0; i<tex_ysz; i++) {
-		for(j=0; j<tex_xsz; j++) {
-			if(j < xsz && i < ysz) {
-				vec3_t rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
-				dir[0] = rdir.x;
-				dir[1] = rdir.y;
-				dir[2] = rdir.z;
-			} else {
-				dir[0] = dir[1] = 0.0f;
-				dir[2] = 1.0f;
-			}
-
-			dir += 3;
+	for(i=0; i<ysz; i++) {
+		for(j=0; j<xsz; j++) {
+			vec3_t rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
+			*dir++ = rdir.x;
+			*dir++ = rdir.y;
+			*dir++ = rdir.z;
 		}
 	}
 
-	glGenTextures(1, &tex);
-	glBindTexture(GL_TEXTURE_2D, tex);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);
+	if(!ray_tex) {
+		glGenTextures(1, &ray_tex);
+	}
+
+	glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cur_tex_xsz);
+	glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cur_tex_ysz);
+
+	if(tex_xsz > cur_tex_xsz || tex_ysz > cur_tex_ysz) {
+		glBindTexture(GL_TEXTURE_2D, ray_tex);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, 0);
+	}
+
+	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, xsz, ysz, GL_RGB, GL_FLOAT, teximg);
 	free(teximg);
 
 	if(tex_scale) {
 		tex_scale->x = (float)xsz / (float)tex_xsz;
 		tex_scale->y = (float)ysz / (float)tex_ysz;
 	}
-	return tex;
+	raytex_needs_recalc = 0;
 }
 
 static vec3_t get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
diff -r b050ce167ff1 -r 57072295eb83 volray.p.glsl
--- a/volray.p.glsl	Sat Mar 31 02:08:42 2012 +0300
+++ b/volray.p.glsl	Mon Apr 02 02:11:35 2012 +0300
@@ -12,6 +12,7 @@
 	vec3 normal;
 };
 
+vec3 sky(Ray ray);
 vec3 ray_march(Ray ray);
 vec3 shade(Ray ray, ISect isect);
 Ray get_primary_ray();
@@ -21,30 +22,37 @@
 	Ray ray = get_primary_ray();
 
 	gl_FragColor = vec4(ray_march(ray), 1.0);
+	//gl_FragColor = vec4(sky(ray), 1.0);
 }
 
-/*vec3 sky(Ray ray)
+vec3 sky(Ray ray)
 {
 	vec3 col1 = vec3(0.75, 0.78, 0.8);
 	vec3 col2 = vec3(0.56, 0.7, 1.0);
 
 	float t = max(ray.dir.y, -0.5);
 	return mix(col1, col2, t);
-}*/
+}
 
 vec3 ray_march(Ray ray)
 {
-	const float ray_step = 0.05;
+	const float ray_step = 0.1;
 	float energy = 1.0;
 	vec3 pos = ray.origin;
+	float col = 0.0;
 
-	// assuming view space
-	while(pos.z < 1.0) {
-		energy -= texture3D(volume, pos).x;
+	for(int i=0; i<40; i++) {
+		float val = texture3D(volume, pos).x;
+		val *= energy;
+		col += val;
+		energy -= val;
+		if(energy < 0.001) {
+			break;
+		}
 		pos += ray.dir * ray_step;
 	}
 
-	return vec3(energy, energy, energy);
+	return vec3(col, col, col);
 }
 
 vec3 shade(Ray ray, ISect isect)