CPU-Raytracer/interface.c

//
// Created by ary on 29.07.2026.
//

#include "interface.h"
#include "examples.h"
#include "structs.h"
#include "vectorOp.h"
#include "raytrace.h"
#include <stdlib.h>
#include "helper.h"

void displaySzene(object objectList[], int objectCount, camera cam1, int width, int height, int channels, unsigned char **image) {
    const vec3 worldUp = (vec3){0, 1, 0};
    vec3 screenX = vec3Cross(worldUp, cam1.direction);
    vec3 screenY = vec3Cross(screenX, cam1.direction);
    vec3 screenMiddlePoint = vec3Add(cam1.origin, vec3Scale(cam1.direction, cam1.screenDistance));
    vec3 screenTopLeft = vec3Add(
        vec3Add(screenMiddlePoint,
            vec3Scale(screenY, -cam1.height/2.0)),///////////////////////////////////////////////////////////////////////////////////////////////////////////////aendern minus weg
        vec3Scale(screenX, -cam1.width/2.0)
        );
    double pixelStepX = cam1.width / cam1.resolutionX;
    double pixelStepY = cam1.height / cam1.resolutionY;
    vec3 vecPixelStepX = vec3Scale(screenX, pixelStepX);
    vec3 vecPixelStepY = vec3Scale(screenY, pixelStepY);
    for (int i = 0; i < height * width; i++) {
        int step = i *channels;
        int x = i % width;
        int y = i / width;
        RGBA pixelColor;

        vec3 *pixelOrigin = (vec3 *)malloc(sizeof(vec3));
        *pixelOrigin = vec3Add(screenTopLeft,
            vec3Add(
                vec3Scale(vecPixelStepX, x),
                vec3Scale(vecPixelStepY, y)
                )
        );

        ray *lightRay = (ray *)malloc(sizeof(ray));;
        lightRay->origin = cam1.origin;

        lightRay->direction = vec3Normalize(vec3Subtract(*pixelOrigin, cam1.origin));

        pixelColor = getPixelColor(objectList,objectCount, lightRay);
        free(pixelOrigin);
        free(lightRay);

        (*image)[step] = (int)(pixelColor.r * 255.0);
        (*image)[step+1] = (int)(pixelColor.g * 255.0);
        (*image)[step+2] = (int)(pixelColor.b * 255.0);
        if (channels == 4) {
            (*image)[step+3] = 255;
        }
    }
}