Macbee

I see! I'm always fascinated by people doing their games in Construct Classic. You're a very rare breed by now, haha.

InvaderXYZ

I think you misunderstood! I was pointing out how you could estimate a budget if you were to do ports from scratch. Maybe your estimate would be accurate if you were doing just that, but of course, the point of Chowdren is to reduce both time & cost needed for Construct ports.

Macbee

The speedup when using Chowdren with Clickteam Fusion is about 7.7x (where the standard runtimes are also written in C++). Admittedly, I don't actually have any data for this, but I would expect the speedup when using Chowdren with Construct Classic to be similar. Do you happen to have a game made for Construct Classic? :)

InvaderXYZ

Hey! Sorry, it looks like your mail got lost in the noise. I remember you had a very small budget for ports, and I'd like to point out that porting is a serious endeavour, requiring many work-hours and time on my part.

I think I need to spend some time to explain, just to set reasonable expectations for smaller developers.

If you were to do the port yourself, you can estimate a ballpark cost. In the most ideal situation, a port would take about one or two months to do. You would likely need to hire a senior engineer that has some knowledge of cross-platform development. If you look at the average salary of a senior engineer in your area, you could start approximating the budget for a port.

I get at lot of emails a day about Chowdren, both regarding Fusion and Construct. Ideally, I would be able to respond to everyone, but usually, I need to prioritize publishers or developers that have at least considered the above.

For developers who do not have a budget for ports, there is still the possibility of revenue share or recoup, of course. In that case, you need to have a strong case for your game, and why revenue would be able to cover the cost of porting instead.

I do not want to discourage anyone from contacting me, since if your game is excellent, I will definitely be in touch! However, I will have infinitely more time to spend on someone who have researched what porting entails, who have already had their game approved for release on consoles, and so on.

Another update: on some platforms, we can get rid of temporary framebuffers entirely for effects that do not use cross-sampling. Most effects do not use cross-sampling, so this significantly improves the performance of effects, especially popular ones like Overlay and Screen.

This is achieved by using memory barriers on platforms that support it (such as console platforms, and Direct3D 11/OpenGL with glTextureBarrier). This allows us to read a texture while writing to it at the same time, so a temporary framebuffer isn't necessary. WebGL does not support memory barriers, which may be a reason why the regular Construct runtimes do not perform this optimization.

As described in the effect compositor writeup from Ashley, objects sometime require predrawing in the standard runtimes, such as when objects are rotated. By using the right texture coordinates for the background texture, we can also skip this step, removing another case where temporary framebuffers are used.

In Chowdren, there are now only a few situations where a temporary framebuffer is required:

• When a layer has 'force own texture', is not fully opaque, or uses an effect, a temporary framebuffer is needed to render the intermediate result.
• When an object uses a cross-sampling effect (such as WarpMask, WaterBg), a partial copy of the background is made.

Headbang Games

Please check your inbox :)

I have some news: Chowdren can now automatically merge effects together. This means that most of the time, Chowdren does not need an intermediate framebuffer to render objects with effects, which the standard runtime will have to do in many cases. If you use a lot of effects, you can expect this to yield some large performance gains.

With the effects merging feature, there is also support for most Construct effects now.

Technical details

Consider two GLSL fragment shaders as follows:

// shader 1, constant multiply
void main() {
 gl_FragColor = texture2D(texture, texture_coordinate);
 gl_FragColor.rgb *= 2.0;
}

// shader 2, monochrome
void main() {
 vec4 col = texture2D(texture, texture_coordinate);
 col *= vec4(0.299, 0.587, 0.114, 1.0);
 col.rgb = vec3(col.r+col.g+col.b);
 gl_FragColor = col;
}

vec4 temp_color_1;
vec2 temp_coord_1;

void main_1() {
 temp_color_1 = texture2D(texture, temp_coord_1);
 temp_color_1 *= 2.0;
}

vec4 sample_1(vec2 tc)
{ temp_coord_1 = tc; main_1(); return temp_color_1; }

void main_2() {
 vec4 col = sample_1(texture_coordinate);
 col *= vec4(0.299, 0.587, 0.114, 1.0);
 col.rgb = vec3(col.r+col.g+col.b);
 gl_FragColor = col;
}

void main() { main_2(); }

void main ()
{
 vec4 col_1;
 col_1 = vec4(0.598, 1.174, 0.228, 2.0) *
 texture2D(texture, texture_coordinate);
 col_1.xyz = vec3(col_1.x + col_1.y + col_1.z);
 gl_FragColor = col_1;
}

In related news, our port of Iconoclasts (made in Construct 1) is releasing on Nintendo Switch on August 2!

I hope we can announce some of the Construct 2 games we are working on soon as well.

elliot

For now, I won't make benchmarks available here. You can contact me by mail or on the Discord server if you'd like more info.

In general, Chowdren is significantly faster than the standard runtimes. However, making specific numbers available would undermine the fact that the standard runtimes are viable for the majority of users. Ashley & team are doing a great job of identifying performance hotspots, as can be seen in their work on the expression compiler.

Cryptwalker

You can send me your project on e.g. the Discord server. Hopefully, I'll have time to take a look soon!

NetOne

It's an interesting idea, but if Chowdren were an official product, people would also assume full and official support for their games. Right now, Chowdren is extended whenever a game we are porting requires it, and that has worked well for us. It allows us to get real games running on Chowdren and to produce real results, and it is clear how our work will be funded.

For now, Chowdren will remain its own runtime. However, I will try to keep Scirra in the loop about Chowdren, in case there is something to learn from the Chowdren approach and vice-versa.

Since some developers have asked me about it, I've looked at what it would take to support C3 under Chowdren. Luckily, it turns out that supporting C3 when used with the C2 runtime is trivial. Here is Bunnymark, exported from C3 using the C2 runtime, and running under Chowdren:

(video)

Supporting the C3 runtime is a different matter, but it should still be doable. The C3 runtime uses a very nice and exciting expression compiler, but this will require some extra work for Chowdren to support. If someone has a use for Chowdren using the C3 runtime, please let me know!