factorygame/entity/entity.c

//
// Created by bruno on 7.6.2025.
//

#include <SDL2/SDL.h>
#include <dirent.h>
#include "entity.h"
#include "../player/player.h"
#include "../util/pathfinding.h"

EntityArray entities;

EntityTypeReg EntityRegistry[ENTITY_MAX_COUNT];

void renderEntities(SDL_Renderer *renderer, SDL_Rect playerRect) {
    SDL_Texture *oldTarget = SDL_GetRenderTarget(renderer);
    SDL_SetRenderTarget(renderer, entityTexture);
    SDL_RenderClear(mainRenderer);
    for (int i = 0; i < entities.activeCount; i++) {
        Entity *ent = &entities.entities[i];
        SDL_Rect renderRect = ent->renderRect;
        adjustRect(&renderRect, playerRect);
        if (!checkCollision(renderRect, screenRect)) {
            continue;
        }
        EntityTypeReg entType = EntityRegistry[ent->type];
        char animationFrame = (animationStep / entType.animation.divisor) % entType.animation.frameCount;
        SDL_RenderCopy(renderer, atlasTexture, &entType.animation.atlasRects[animationFrame], &renderRect);
    }
    SDL_SetRenderTarget(renderer, oldTarget);
}

void updateEntities() {
    for (int i = 0; i < entities.activeCount; i++) {
        Entity *ent = &entities.entities[i];
        EntityTypeReg entT = EntityRegistry[ent->type];

        // Step 1: If no path, or we're at the end of a path, check for re-path
        bool atTargetSnapshot = ent->tileRect.x == ent->targetSnapshot.x &&
                                ent->tileRect.y == ent->targetSnapshot.y;

        bool needsPath = ent->path.length == 0 || ent->path.stepIndex >= ent->path.length;

        if (needsPath && (atTargetSnapshot || ent->path.length == 0)) {
            if (ent->tileRect.x != ent->target.x || ent->tileRect.y != ent->target.y) {
                if (isWalkable(ent->target) && find_path(ent->tileRect, ent->target)) {
                    ent->path = reconstruct_path(ent->target);
                    ent->path.stepIndex = 0;
                    ent->targetSnapshot = ent->target; // snapshot the current target
                    ent->fromTile = ent->tileRect;
                    ent->toTile = ent->path.steps[0];
                    ent->interpolateTick = 0;
                    ent->entityNextTick = animationStep + entT.entityTickRate;
                } else {
                    // No path found — freeze
                    ent->path.length = 0;
                    continue;
                }
            }
        }

        // Step 2: If it's time to move to the next tile
        if (ent->path.length > 0 && ent->path.stepIndex < ent->path.length &&
            animationStep >= ent->entityNextTick) {
            ent->fromTile = ent->tileRect;
            ent->toTile = ent->path.steps[ent->path.stepIndex];
            ent->tileRect = ent->toTile;
            ent->entityNextTick = animationStep + entT.entityTickRate;
            ent->interpolateTick = 0;
            ent->path.stepIndex++;
        }

        // Step 3: Interpolate renderRect between fromTile and toTile
        MiniRect from = {
                .x = ent->fromTile.x * TILE_SIZE,
                .y = ent->fromTile.y * TILE_SIZE
        };
        MiniRect to = {
                .x = ent->toTile.x * TILE_SIZE,
                .y = ent->toTile.y * TILE_SIZE
        };

        float t = (float)ent->interpolateTick / entT.entityTickRate;
        ent->renderRect.x = (int)(from.x + (to.x - from.x) * t);
        ent->renderRect.y = (int)(from.y + (to.y - from.y) * t);

        if (ent->interpolateTick < entT.entityTickRate) {
            ent->interpolateTick++;
        }
    }
}




void registerEntity(char fname[20], SDL_Renderer *renderer) {
    char name[21];

    // Load animation frames
    int frame = 0;
    int indexEntity = 0;
    char texturePath[80];

    if (sscanf(fname, "%d_%20[^_]_%d.png", &indexEntity, name, &frame) == 3) {
        // Success: you now have index, fname, and frame
    } else {
        fprintf(stderr, "Invalid format: %s\n", fname);
    }
    strcpy(EntityRegistry[indexEntity].name, name);
    snprintf(texturePath, sizeof(texturePath), "./assets/entities/%s", fname);
    SDL_Texture *texture = IMG_LoadTexture(renderer, texturePath);
    if (!texture) {
        if (frame == 0) {
            fprintf(stderr, "Failed to load entity texture %s: %s\n", texturePath, IMG_GetError());
        }
    }

    SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_NONE);

    printf("Ent %s to %d\n", fname, indexEntity);

    EntityRegistry[indexEntity].animation.textures[frame] = texture;
    EntityRegistry[indexEntity].animation.atlasRects[frame] = allocate_32x32(texture, renderer);

    EntityRegistry[indexEntity].type = indexEntity;
    EntityRegistry[indexEntity].animation.frameCount = frame + 1;
    EntityRegistry[indexEntity].animation.divisor = 1;
    EntityRegistry[indexEntity].entityTickRate = 8;

    if (indexEntity + 1 > backgroundTileTypeIndex) {
        backgroundTileTypeIndex = indexEntity + 1;
    }
}

void loadEntities(SDL_Renderer *renderer) {
    DIR *dir = opendir("./assets/entities");
    if (!dir) {
        perror("Failed to open entities directory");
        return;
    }

    char *entityNames[ENTITY_MAX_COUNT];
    int entityCount = 0;

    struct dirent *entry;
    while ((entry = readdir(dir))) {
        char *dot = strrchr(entry->d_name, '.');
        if (!dot || strcmp(dot, ".png") != 0) continue;

        // Check if baseName already stored
        int found = 0;
        for (int i = 0; i < entityCount; ++i) {
            if (strcmp(entityNames[i], entry->d_name) == 0) {
                found = 1;
                break;
            }
        }

        if (!found && entityCount < ENTITY_MAX_COUNT) {
            entityNames[entityCount++] = strdup(entry->d_name);  // Only store base, not full file name
        }
    }
    closedir(dir);

    qsort(entityNames, entityCount, sizeof(char *), compareStrings);

    // Call registerEntity on each base name
    for (int i = 0; i < entityCount; ++i) {
        char fileName[64];
        snprintf(fileName, sizeof(fileName), "%s", entityNames[i]);
        registerEntity(fileName, renderer);
        free(entityNames[i]);
    }
}

int add_entity(EntityArray *arr, Entity t) {
    if (arr->activeCount >= ENTITY_MAX_COUNT) return 0;
    arr->entities[arr->activeCount] = t;
    arr->activeCount++;
    return arr->activeCount - 1;
}

void remove_entity(EntityArray *arr, int index) {
    if (index < 0 || index >= arr->activeCount) return;
    arr->activeCount--;
    arr->entities[index] = arr->entities[arr->activeCount];  // swap with last active
}