r3d/examples/sprite_instanced.c

#include "./common.h"
#include "r3d.h"
#include "raylib.h"
#include "raymath.h"

/* === Resources === */

static Camera3D camera = { 0 };

static R3D_Mesh plane = { 0 };
static R3D_Material material = { 0 };

static Texture2D texture = { 0 };
static R3D_Sprite sprite = { 0 };

static Matrix transforms[64] = { 0 };

/* === Examples === */

const char* Init(void)
{
    /* --- Initialize R3D with its internal resolution --- */

    R3D_Init(GetScreenWidth(), GetScreenHeight(), 0);
    SetTargetFPS(60);

    /* --- Set the background color --- */

    R3D_SetBackgroundColor(SKYBLUE);

    /* --- Generate a large plane to act as the ground --- */

    plane = R3D_GenMeshPlane(200, 200, 1, 1, true);
    material = R3D_GetDefaultMaterial();
    material.albedo.color = GREEN;

    /* --- Load a texture and create a sprite --- */

    texture = LoadTexture(RESOURCES_PATH "tree.png");

    sprite = R3D_LoadSprite(texture, 1, 1);
    sprite.material.shadowCastMode = R3D_SHADOW_CAST_ALL_FACES;

    /* --- Create multiple transforms for instanced sprites with random positions and scales --- */

    for (int i = 0; i < sizeof(transforms) / sizeof(*transforms); i++) {
        float scaleFactor = GetRandomValue(25, 50) / 10.0f;
        Matrix scale = MatrixScale(scaleFactor, scaleFactor, 1.0f);
        Matrix translate = MatrixTranslate(GetRandomValue(-100, 100), scaleFactor, GetRandomValue(-100, 100));
        transforms[i] = MatrixMultiply(scale, translate);
    }

    /* --- Setup the scene lighting --- */

    R3D_SetSceneBounds(
        (BoundingBox) {
            .min = { -100, -10, -100 },
            .max = { +100, +10, +100 }
        }
    );

    R3D_Light light = R3D_CreateLight(R3D_LIGHT_DIR);
    {
        R3D_SetLightDirection(light, (Vector3) { -1, -1, -1 });
        R3D_EnableShadow(light, 4096);
        R3D_SetShadowBias(light, 0.0025f);
        R3D_SetLightActive(light, true);
    }

    /* --- Setup the camera --- */

    camera = (Camera3D){
        .position = (Vector3) { 0, 5, 0 },
        .target = (Vector3) { 0, 5, -1 },
        .up = (Vector3) { 0, 1, 0 },
        .fovy = 60,
    };

    /* --- Capture the mouse and let's go! --- */

    DisableCursor();

    return "[r3d] - Instanced sprites example";
}

void Update(float delta)
{
    UpdateCamera(&camera, CAMERA_FREE);
}

void Draw(void)
{
    R3D_Begin(camera);

    R3D_DrawMesh(&plane, &material, MatrixTranslate(0, 0, 0));
    R3D_DrawSpriteInstanced(&sprite, transforms, sizeof(transforms) / sizeof(*transforms));

    R3D_End();
}

void Close(void)
{
    R3D_UnloadSprite(&sprite);
    R3D_UnloadMesh(&plane);
    UnloadTexture(texture);
    R3D_Close();
}