I have to admit that the Factorio development is slowed down these days, but it is not stopped because it just can't stop. Or is it because we can't stop? I guess that we have come too far to give up who we are.
Hello, so today is Saturday (more specifically half past six on Saturday morning). The point of Friday Facts is that they are written on Friday. So what went wrong? Yesterday we were working all day long to make the promised release happen. We gave up on social life on Friday evenings long time ago:/ There were new and new things coming up. At one point we were ready to "push the release button" but then we found out that the game performance can drop significantly due to some strange Allegro sound issues. As a result the game was not playable at all. That was already late in the evening and we started to fall asleep over our keyboards.
Hello, 0.12 will be stable soon, so is a good time to start making you want things from 0.13 right? :)
Hello, A bunch of us will be travelling to Gamescom next week as visitors, if you see anybody wearing a Factorio t-shirt, it might very well be one of us. We don't have a booth or exhibit this year, as we don't want to take any focus away from the development of the game.
We are aware that we don't add so much content to Factorio these days. The reason we always state is that we are focusing on polishing and finishing the game. There are a lot of little things and details (some call it quality of life improvements), that don't look that awesome when reviewed one by one, but once they accumulate together they should make a big difference in the game experience. I'm going to talk about some of them now, but don't be afraid that we won't add anything new in the 0.16, as the work on the artillery train has already started and it is probably going to be epic :).
Hello, Albert is back this week, and has resumed his work on the liquid wagon and associated accessories, as well as offering his guidance to some visual related programming tasks. Kuba and Honza are also both back from their respective holidays, and overall the office is feeling much more full than last week.
I need to make a confession. I'm addicted. Addicted to optimisation.
Cars/Tanks remember their color Klonan This really is a tiny feature, the car and tank will now save the color of the passengers when they exit the vehicle. So now you won't forget which vehicle you were driving, and can warn everyone else on the server: "Pink tank is mine".
Hello, these Friday Facts are focused solely on our view of gameplay issues in Factorio, and our plans to solve these.
Alpha blending and pre-multiplied alpha From time to time there is some confusion inside the team about how sprites are blended with the background when rendering, and what kind of effects we are able to achieve by tinting the sprites. So I (Posila) have decided to write up a few paragraphs about how alpha blending works (not only in Factorio), and what it means when someone talks about pre-multiplied alpha. When the GPU is figuring out what color it should draw on a particular pixel position, it runs a blending operation on just the computed pixel color and original color in the render target. There are several common blending operation modes (additive, multiplicative, overwrite, etc.), but the most common one used in Factorio is alpha blending. It calculates the resulting color using following equation (usually the new color is called 'source' and the background color that is being overwritten is called 'destination'): You can easily see that a source with alpha 0 will be fully transparent and the one with alpha 1 will be fully opaque. In games it is common to use a pre-multiplied alpha, which means the color channels of textures are stored in memory being already pre-multiplied by the alpha channel. Alpha blending with pre-multiplied alpha uses a simplified equation: Besides a slight performance gain from the GPU not having to do bunch of multiplication all the time, this equation allow us to do some extra effects we couldn't do without pre-multiplied alpha. Factorio renders sprites as colored polygons with texture. We usually refer to the color of a polygon as the 'tint', and every pixel of a sprite is multiplied with its tint. This is useful mainly for color masks, for example the diesel locomotive has a grayscale color mask which is tinted by the color it has set. Tints should have a pre-multiplied alpha too, but they don't have to, so we can use it to lie about the colors and alpha to the GPU. For example if we use tint {r=1,g=1,b=1,a=0} we can simplify previous equation even further and we get additive blending: This is great because that means we can switch between alpha and additive blending without having to change the blending state in graphics API, which would break sprite batching and result in an increase in the CPU cost of rendering. For some effects we use a tint with alpha between 0 and 1 heavily. This makes the result appear to be a combination of additive and alpha blending. For example, fire would eventually blend into a single solid color with pure additive blending, or would not look like it is emitting light with pure alpha blending. By using tint (1, 1, 1, 0.35) on the flame sprites, the brightness of overlapping flames adds up partially, but the flames don't completely lose their details. The same trick is used for smoke. Textures with pre-multiplied alpha also produce better results in texture filtering , which is probably the main reason why they are so widely used in the videogame industry.
