To get the normal color is the most trickier ever I see in PB because in C++ is easy but not PB :/
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;
; Inspired from Ray Tracing in One Weekend :
; https://raytracing.github.io/books/RayTracingInOneWeekend.html
;
; Writed and adapted in Purebasic by threedslider
;
aspect_ratio.f = 16.0 / 9.0
image_width = 800
image_height = Int(image_width / aspect_ratio)
If image_height < 1
image_height = 1
Else
image_height = image_height
EndIf
focal_length.f = 1.0
viewport_height.f = 2.0
i_w.f = image_width
i_h.f = image_height
viewport_width.f = viewport_height * (i_w/i_h)
; Vector
Structure Vec3
x.f
y.f
z.f
EndStructure
; Ray
Structure Ray
orig.Vec3
dir.Vec3
EndStructure
point3.Vec3
point3\x = 0
point3\y = 0
point3\z = 0
ray_direction.Vec3
ray_direction\x = 0
ray_direction\y = 0
ray_direction\z = 0
viewport_u.Vec3
viewport_u\x = viewport_width
viewport_u\y = 0
viewport_u\z = 0
viewport_v.Vec3
viewport_v\x = 0
viewport_v\y = -viewport_height
viewport_v\z = 0
pixel_delta_u.Vec3
pixel_delta_u\x = viewport_u\x / i_w
pixel_delta_u\y = viewport_u\y / i_w
pixel_delta_u\z = viewport_u\z / i_w
;Debug pixel_delta_u\x
pixel_delta_v.Vec3
pixel_delta_v\x = viewport_v\x / i_h
pixel_delta_v\y = viewport_v\y / i_h
pixel_delta_v\z = viewport_v\z / i_h
;Debug pixel_delta_v\y
viewport_upper_left.Vec3
v_f.Vec3
v_f\x = 0.0
v_f\y = 0.0
v_f\z = focal_length
viewport_upper_left\x = point3\x - v_f\x - viewport_u\x / 2 - viewport_v\x / 2
viewport_upper_left\y = point3\y - v_f\y - viewport_u\y / 2 - viewport_v\y / 2
viewport_upper_left\z = point3\z - v_f\z - viewport_u\z / 2 - viewport_v\z / 2
;Debug viewport_u\x / 2
;Debug viewport_upper_left\x
pixel_100_loc.Vec3
pixel_100_loc\x = viewport_upper_left\x + 0.5 * (pixel_delta_u\x + pixel_delta_v\x)
pixel_100_loc\y = viewport_upper_left\y + 0.5 * (pixel_delta_u\y + pixel_delta_v\y)
pixel_100_loc\z = viewport_upper_left\z + 0.5 * (pixel_delta_u\z + pixel_delta_v\z)
Procedure.f dot(*v1.Vec3, *v2.Vec3)
result.f = *v1\x * *v2\x + *v1\y * *v2\y + *v1\z * *v2\z
ProcedureReturn result
EndProcedure
Procedure.f v_length(*v.Ray)
result.f = Sqr(*v\dir\x * *v\dir\x + *v\dir\y * *v\dir\y + *v\dir\z * *v\dir\z)
;Debug result
ProcedureReturn result
EndProcedure
Procedure.f unit_vector_y(*vy.Ray)
len.f = v_length(*vy)
y.f = 0
If Not len = 0 ;And Not len < 0
y = *vy\dir\y / len
EndIf
;Debug vv
ProcedureReturn y
EndProcedure
Procedure.f at(*rr.Ray, t.f, axe)
If axe = 1
x.f = (*rr\orig\x + t * *rr\dir\x)
ProcedureReturn (x)
EndIf
If axe = 2
y.f = (*rr\orig\y + t * *rr\dir\y)
ProcedureReturn (y)
EndIf
If axe = 3
z.f = (*rr\orig\z + t * *rr\dir\z)
ProcedureReturn (z)
EndIf
EndProcedure
Procedure.f unit_vector_normal(x.f, y.f, z.f, axe)
len.f = Sqr(x*x + y*y + z*z)
xx.f = 0
yy.f = 0
zz.f = 0
If Not len = 0
xx = x / len
EndIf
If Not len = 0
yy = y / len
EndIf
If Not len = 0
zz = z / len
EndIf
If axe = 1
ProcedureReturn xx
EndIf
If axe = 2
ProcedureReturn yy
EndIf
If axe = 3
ProcedureReturn zz
EndIf
EndProcedure
Procedure.f ray_color_n(x.f, y.f, z.f, axe)
color1.Vec3
color2.Vec3
color1\x = x
color1\y = y
color1\z = z
x.f = 0.5 * color1\x + 1.0
y.f = 0.5 * color1\y + 1.0
z.f = 0.5 * color1\z + 1.0
If axe = 1
ProcedureReturn x
EndIf
If axe = 2
ProcedureReturn y
EndIf
If axe = 3
ProcedureReturn z
EndIf
EndProcedure
Procedure.f ray_color(*rr.Ray, axe)
color1.Vec3
color2.Vec3
color1\x = 1.0
color1\y = 1.0
color1\z = 1.0
color2\x = 0.5
color2\y = 0.7
color2\z = 1.0
unit_direction.Vec3
unit_direction\x = unit_vector_y(*rr)
a1.f = 0.5 * (unit_direction\x + 1.0)
x.f = (1.0 - a1) * color1\x + a1 * color2\x
unit_direction\y = unit_vector_y(*rr)
a2.f = 0.5 * (unit_direction\y + 1.0)
y.f = (1.0 - a2) * color1\y + a2 * color2\y
unit_direction\z = unit_vector_y(*rr)
a3.f = 0.5 * (unit_direction\z + 1.0)
z.f = (1.0 - a3) * color1\z + a3 * color2\z
If axe = 1
ProcedureReturn x
EndIf
If axe = 2
ProcedureReturn y
EndIf
If axe = 3
ProcedureReturn z
EndIf
EndProcedure
Procedure.f hit_sphere(*posx.Vec3, radius.f, *vx.Ray)
oc.Vec3
oc\x = *vx\orig\x - *posx\x
oc\y = *vx\orig\y - *posx\y
oc\z = *vx\orig\z - *posx\z
a.f = dot(*vx\dir, *vx\dir)
b.f = 2.0 * dot(oc,*vx\dir)
c.f = dot(oc,oc) - radius*radius
discriminant.f = b*b - 4*a*c
If discriminant < 0
ProcedureReturn -1.0
Else
dis.f = (-b - Sqr(discriminant) ) / (2.0*a);
ProcedureReturn dis
EndIf
EndProcedure
; Write the translated [0,255] value of each color component.
Procedure write_color()
Shared pixel_color.Vec3
WriteString(0, Str(Int(255.999 * pixel_color\x)))
WriteString(0, " ")
WriteString(0, Str(Int(255.999 * pixel_color\y)))
WriteString(0, " ")
WriteString(0, Str(Int(255.999 * pixel_color\z)))
WriteStringN(0, " ")
;Debug Str(Int(255.999 * pixel_color\x))
EndProcedure
; Output the image in PPM
; If CreateFile(0, "image_test4.ppm")
; WriteStringN(0,"P3")
; WriteString(0,Str(image_width))
; WriteString(0," ")
; WriteString(0,Str(image_height))
; WriteStringN(0," ")
; WriteStringN(0,"255")
; WriteStringN(0," ")
;
; For j = 0 To image_height-1
; For i = 0 To image_width-1
;
; ii.f = i
; jj.f = j
;
; pixel_center.Vec3
;
; Define.Vec3 pixel_color
;
; pixel_center\x = pixel_100_loc\x + (ii * pixel_delta_u\x) + (jj * pixel_delta_v\x)
; pixel_center\y = pixel_100_loc\y + (ii * pixel_delta_u\y) + (jj * pixel_delta_v\y)
; pixel_center\z = pixel_100_loc\z + (ii * pixel_delta_u\z) + (jj * pixel_delta_v\z)
;
; ;Debug pixel_center\x
;
; ray_direction\x = pixel_center\x - point3\x
; ray_direction\y = pixel_center\y - point3\y
; ray_direction\z = pixel_center\z - point3\z
;
; ;Debug ray_direction\x
;
; Define.Ray r
;
; r\orig = point3
; r\dir = ray_direction
;
; Define.Ray myray
;
; myray\orig = point3
; myray\dir = ray_direction
;
; p_s.Vec3
;
; p_s\x = 0
; p_s\y = 0
; p_s\z = -1
;
; If hit_sphere(p_s, 0.5, r)
; pixel_color\x = 1.0
; pixel_color\y = 0
; pixel_color\z = 0
; Else
; pixel_color\x = ray_color_x(r)
; pixel_color\y = ray_color_y(r)
; pixel_color\z = ray_color_z(r)
; EndIf
;
; ;Debug pixel_color\x
; write_color()
;
;
; Next
; Next
; CloseFile(0)
; EndIf
InitSprite()
OpenWindow(0, 0, 0, image_width, image_height, "Inspired from Raytracing in One Weekend", #PB_Window_SystemMenu|#PB_Window_ScreenCentered)
OpenWindowedScreen(WindowID(0), 0, 0, image_width, image_height)
ClearScreen(RGB(0,0,0))
If StartDrawing(ScreenOutput())
For j = 0 To image_height-1
For i = 0 To image_width-1
ii.f = i
jj.f = j
pixel_center.Vec3
Define.Vec3 pixel_color
pixel_center\x = pixel_100_loc\x + (ii * pixel_delta_u\x) + (jj * pixel_delta_v\x)
pixel_center\y = pixel_100_loc\y + (ii * pixel_delta_u\y) + (jj * pixel_delta_v\y)
pixel_center\z = pixel_100_loc\z + (ii * pixel_delta_u\z) + (jj * pixel_delta_v\z)
;Debug pixel_center\x
ray_direction\x = pixel_center\x - point3\x
ray_direction\y = pixel_center\y - point3\y
ray_direction\z = pixel_center\z - point3\z
;Debug ray_direction\x
Define.Ray r
r\orig = point3
r\dir = ray_direction
Define.Ray myray
myray\orig = point3
myray\dir = ray_direction
p_s.Vec3
p_s\x = 0
p_s\y = 0
p_s\z = -1
t.f = hit_sphere(p_s, 0.5, r)
;Debug Plot(i, j, RGB(Int(255.999 * ray_color_n(1,1,1,1)),0,0)
If t > 0.0
Plot(i, j, Plot(i, j, RGB(Int(255.999 * ray_color_n(unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),1),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),2),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),3),1)),Int(255.999 * ray_color_n(unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),1),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),2),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),3),2)),Int(255.999 * ray_color_n(unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),1),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),2),unit_vector_normal(at(r,t,1),at(r,t,2),at(r,t,3),3),1)))))
Else
Plot(i, j, RGB(Int(255.999 * ray_color(r,1)),Int(255.999 * ray_color(r,2)),Int(255.999* ray_color(r,3))))
EndIf
Next
Next
StopDrawing()
EndIf
Repeat
Event = WindowEvent()
Until Event = #PB_Event_CloseWindow
End
: https://raytracing.github.io/books/RayT ... ekend.html
but I was making an image test in ppm as this article show.
