From a99f5e3531e21f29b65d33a5a224bbdebc43bcd9 Mon Sep 17 00:00:00 2001
From: Rokas Puzonas <rokas.puz@gmail.com>
Date: Wed, 29 Nov 2023 23:25:40 +0200
Subject: [PATCH] update camera class

---
 src/camera.cpp | 16 +++++++++++-----
 src/main.cu    | 10 +++++++---
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/camera.cpp b/src/camera.cpp
index 49e3bf5..a7416ce 100644
--- a/src/camera.cpp
+++ b/src/camera.cpp
@@ -4,11 +4,17 @@
 
 class camera {
 public:
-    __device__ camera() {
-        lower_left_corner = vec3(-2.0, -1.0, -1.0);
-        horizontal        = vec3( 4.0,  0.0,  0.0);
-        vertical          = vec3( 0.0,  2.0,  0.0);
-        origin            = vec3( 0.0,  0.0,  0.0);
+    __device__ camera(vec3 lookfrom, vec3 lookat, vec3 vup, float vfov, float aspect) {
+        float theta = vfov*M_PI/180;
+        float half_height = tan(theta/2);
+        float half_width  = aspect*half_height;
+        origin = lookfrom;
+        vec3 w = unit_vector(lookfrom - lookat);
+        vec3 u = unit_vector(cross(vup, w));
+        vec3 v = cross(w, u);
+        lower_left_corner = origin - half_width*u - half_height*v - w;
+        horizontal = 2*half_width*u;
+        vertical   = 2*half_height*v;
     }
     __device__ ray get_ray(float u, float v) {
         return ray(origin, lower_left_corner + u*horizontal + v*vertical - origin);
diff --git a/src/main.cu b/src/main.cu
index 2ea1323..b77bc51 100644
--- a/src/main.cu
+++ b/src/main.cu
@@ -93,7 +93,7 @@ __global__ void render(vec3 *fb,
     fb[pixel_idx] = col;
 }
 
-__global__ void create_world(hitable **d_list, int d_list_size, hitable **d_world, camera **d_camera) {
+__global__ void create_world(hitable **d_list, int d_list_size, hitable **d_world, camera **d_camera, int nx, int ny) {
     if (threadIdx.x == 0 && blockIdx.y == 0) {
         d_list[0] = new sphere(vec3( 0,    0  , -1),  0.5, new lambertian(vec3(0.1, 0.2, 0.5)));
         d_list[1] = new sphere(vec3( 0, -100.5, -1),  100, new lambertian(vec3(0.8, 0.8, 0.0)));
@@ -101,7 +101,11 @@ __global__ void create_world(hitable **d_list, int d_list_size, hitable **d_worl
         d_list[3] = new sphere(vec3(-1,    0  , -1),  0.5, new dielectric(1.5));
         d_list[4] = new sphere(vec3(-1,    0  , -1), -0.45, new dielectric(1.5));
         *d_world  = new hitable_list(d_list, d_list_size);
-        *d_camera = new camera();
+        *d_camera = new camera(vec3(-2,2,1),
+                                vec3(0,0,-1),
+                                vec3(0,1,0),
+                                20.0,
+                                float(nx)/float(ny));
     }
 }
 
@@ -144,7 +148,7 @@ int main() {
     checkCudaErrors(cudaMalloc((void **)&d_world, sizeof(hitable *)));
     camera **d_camera;
     checkCudaErrors(cudaMalloc((void **)&d_camera, sizeof(camera *)));
-    create_world<<<1,1>>>(d_list, d_list_size, d_world, d_camera);
+    create_world<<<1,1>>>(d_list, d_list_size, d_world, d_camera, nx, ny);
     checkCudaErrors(cudaGetLastError());
     checkCudaErrors(cudaDeviceSynchronize());