diff options
Diffstat (limited to 'viewport.h')
| -rw-r--r-- | viewport.h | 74 |
1 files changed, 42 insertions, 32 deletions
@@ -18,6 +18,7 @@ #include <iostream> #include <cstdint> #include <random> +#include <cmath> // bias context, used for placing sub-pixels class bias_ctx { @@ -41,32 +42,40 @@ public: } }; -template<typename T> -class viewport { -public: - virtual bitmap<T> render(const hitlist &world, vec3d viewpoint, uint16_t image_width, uint16_t image_height) = 0; - - virtual ~viewport() = default; -}; - +// TODO rename to camera // Single sampled viewport which supports bias sampling -template<typename T> -class basic_viewport : public viewport<T> { - const double half_width, half_height; // viewport size - const vec3d center; // coordinate of the viewport center point - +// U: color depth, V: pos +template<typename U, typename V> +class basic_viewport { + vec3<V> cxyz; // coordinate of the focus point + vec3<V> screen_center; +// double pitch; // TODO implement +// double yaw; // TODO implement + uint32_t image_width; // how many pixels every row has + uint32_t image_height; // how many pixels every column has + V screen_hw; // determined if screen_height is known + V screen_hh; // determined if screen_width is known +// double fov_h; // horizontal FOV, determined if screen_width or screen_height is known +// double focus_length; // distance between the focus point and the image screen + hitlist &world; public: - basic_viewport() = delete; - basic_viewport(double width, double height, vec3d viewport_center) : - half_width(width / 2.0), half_height(height / 2.0), center(viewport_center) {} + basic_viewport(const vec3<V> &cxyz, const vec3<V> &screen_center, + uint32_t image_width, uint32_t image_height, + double fov_h, hitlist &world) : + cxyz{cxyz}, screen_center{screen_center}, image_width{image_width}, image_height{image_height}, + screen_hw{(cxyz - screen_center).norm() * tan((double) fov_h / 2.0)}, + screen_hh{screen_hw * ((double) image_height / image_width)}, + world{world} {} - virtual bitmap<T> - render(const hitlist &world, vec3d viewpoint, uint16_t image_width, uint16_t image_height) override { - bias_ctx bc{}; - static constexpr uint64_t default_diffuse_seed = 123456789012345678ULL; - return render(world, viewpoint, image_width, image_height, bc, default_diffuse_seed); - } + basic_viewport(const vec3<V> &cxyz, const vec3<V> &screen_center, + uint32_t image_width, uint32_t image_height, + double screen_hw, double screen_hh, + hitlist &world) : + cxyz{cxyz}, screen_center{screen_center}, image_width{image_width}, image_height{image_height}, + screen_hw{screen_hw}, + screen_hh{screen_hh}, + world{world} {} /** * Generate the image seen on given viewpoint. @@ -74,13 +83,14 @@ public: * @param by bias on y axis (0.0 <= by < 1.0) * @return */ - virtual bitmap<T> render(const hitlist &world, vec3d viewpoint, - uint16_t image_width, uint16_t image_height, - bias_ctx &bias, uint64_t diffuse_seed) const { - bitmap<T> image{image_width, image_height}; + bitmap<U> render(uint64_t diffuse_seed, bias_ctx &bias + /* by putting thread-specific parameters in call argument list, make users convenient*/) const { + // The implementation keep all mutable state in local stack, + // keeping the class immutable and thread-safe. + bitmap<U> image{image_width, image_height}; random_uv_gen_3d ruvg{diffuse_seed}; - double bx, by; - const auto r = center - viewpoint; + V bx, by; + const auto r = screen_center - cxyz; const int img_hw = image_width / 2, img_hh = image_height / 2; // iterate over every pixel on the image for (int j = -img_hh + 1; j <= img_hh; ++j) { // axis y, transformation is needed @@ -91,13 +101,13 @@ public: assert(bx < 1.0); assert(by < 1.0); const vec3d off{ - .x=(1.0 * i + bx) / img_hw * half_width, - .y=(1.0 * j + by) / img_hh * half_height, + .x=(1.0 * i + bx) / img_hw * screen_hw, + .y=(1.0 * j + by) / img_hh * screen_hh, .z=0.0 }; // offset on screen plane const auto dir = r + off; // direction vector from camera to current pixel on screen - ray3d ray{viewpoint, dir}; // from camera to pixel (on the viewport) - const auto pixel = world.color<T>(ray, ruvg); + ray3d ray{cxyz, dir}; // from camera to pixel (on the viewport) + const auto pixel = world.color<U>(ray, ruvg); const auto x_ = i + img_hw, y_ = -j + img_hh; image.set(x_, y_, pixel); |