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#include "renderer.h"
#include "screen.h"
#include "ray.h"
#include <math.h>
#include <stdio.h>
#include <string.h>
static void verline(Swapchain* swapchain, int x, int y0, int y1, uint32_t color) {
for (int y = y0; y <= y1; y++) {
swapchain->images[swapchain->image_current][(y * swapchain->width) + x] = color;
}
}
void render(Screen* screen, const Camera* camera) {
const v2 cam_right = {
-sin(camera->angle),
cos(camera->angle)
};
Swapchain* swapchain = &screen->swapchain;
swapchain_next(swapchain);
for (int x = 0; x < screen->swapchain.width; x++) {
const float xcam = (2 * (x / (float) (swapchain->width))) - 1;
const float change = camera->fov * atan(xcam);
const float theta = camera->angle + change;
v2 hit_pos;
uint32_t hit = cast_ray(camera->pos, theta, &hit_pos);
hit_pos.x -= camera->pos.x;
hit_pos.y -= camera->pos.y;
float len = v2_cross(hit_pos, cam_right) / v2_len(cam_right);
uint32_t color;
switch (hit) {
case 1: color = 0xFFFF0000; break;
case 2: color = 0xFF00FF00; break;
case 3: color = 0xFF0000FF; break;
case 4: color = 0xFFFF00FF; break;
case 5: color = 0xFF00FFFF; break;
default: color = 0xFF000000; break;
}
const int
h = (int) (swapchain->height / len),
y0 = max((swapchain->height / 2) - (h / 2), 0),
y1 = min((swapchain->height / 2) + (h / 2), swapchain->height - 1);
verline(swapchain, x, 0, y0, 0xFF202020);
verline(swapchain, x, y0, y1, color);
verline(swapchain, x, y1, swapchain->height - 1, 0xFF505050);
}
swapchain_submit(swapchain);
}
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