Drawing multiple cubes using instancing

[nitanmarcel]

Hello. Looking at the instancing example, I don't quite understand how to work with it. I have a simple code written in zig that is supposed to draw multiple cubes on an axis using instancing but it doesn't work for me.

Can someone help me? Thanks.

const std = @import("std");
const rl = @import("raylib");
const gl = @import("rlgl");
const math = @import("raylib-math");

const Vector3 = struct {
    const init = rl.Vector3.init;
    const up = rl.Vector3.init(0.0, 1.0, 0.0);
    const zero = rl.Vector3.init(0.0, 0.0, 0.0);
};

pub fn main() !void {
    const screen_width = 800;
    const screen_height = 600;

    rl.initWindow(screen_width, screen_height, "Raylib");
    rl.disableCursor();

    var camera = rl.Camera3D{
        .position = Vector3.init(-125.0, 125.0, -125.0),
        .target = Vector3.init(0.0, 0.0, 0.0),
        .up = Vector3.up,
        .fovy = 45.0,
        .projection = rl.CameraProjection.camera_perspective,
    };

    const allocator = std.heap.page_allocator;

    const max_instances: usize = 10000;
    var transforms = try allocator.alloc(rl.Matrix, max_instances);

    const img = rl.loadImage("assets/image.png");
    const tex = img.toTexture();
    const cube = rl.genMeshCubicmap(img, Vector3.init(1.0, 1.0, 1.0));
    var cubePosition = Vector3.zero;

    var mat = rl.loadMaterialDefault();
    const difuse = @intFromEnum(rl.MATERIAL_MAP_DIFFUSE);
    mat.maps[difuse].color = rl.Color.red;

    const cubeSize = 2.0;
    for (0..max_instances) |y| {
        const y_f: f32 = @floatFromInt(y);
        const next_pos = y_f * cubeSize;
        cubePosition.x = cubePosition.x + next_pos;
        const translation = math.matrixTranslate(cubePosition.x, cubePosition.y, cubePosition.z); //gl.rlTranslatef(cubePosition.x, cubePosition.y, cubePosition.z);
        transforms[y] = translation;
    }

    defer {
        allocator.free(transforms);
        img.unload();
        tex.unload();
        rl.closeWindow();
    }

    rl.setTargetFPS(60);

    while (!rl.windowShouldClose()) {
        camera.update(rl.CameraMode.camera_free);

        rl.beginDrawing();
        rl.clearBackground(rl.Color.ray_white);

        camera.begin();

        cube.drawInstanced(mat, transforms);

        camera.end();

        rl.endDrawing();
    }
}