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* Forwarded from BBRZXNet from : SAV/D.M.G./U.A. to: All amateurs! subj : All sorts of useful things date : 12-04-98 time: 21:48 Hello All! I absolutely don’t want to sleep, but I want to tell you need some information for general development, so to speak: So, excerpts from the book 'Applied Graphics' Inforcom. Methods for presenting graphic information: 1. Raster graphics 2. Vector graphics 3. Block graphics Let's move on to analyzing each one separately: 1. Raster - the image on the screen consists of pre-defined 'pictures' small (not always) sizes that overlap each other and that's it put the image together. Almost all graphics on Spectrum is exactly like that. 2. Vector - the image is constructed according to the given situation, it is not known in advance, so it is calculated according to formulas and is drawn by straight segments (vectors, which is called vector). Possibly an incalculable number combinations, which ensures undoubted success with toy lovers. These are games such as Elite, Academy, Tau Ceta II. Polygons are a separate subclass simulators where painting is used seriously planes of figures with textures, hiding invisible contours and collisions (object deformations). K such games include: Battle Command and CarrierCommand. 3. Block - the poorest, but also the most economical. Obviously, all system programs use block graphics. The only exception is Windows'95. So - block graphics are a simplified version of raster graphics. All objects consist of identical pieces (blocks) of which the object is assembled. So, for example, block graphics are text on the screen - the text itself is codes characters, and their image is a font. Illustrative examples of games, using block graphics - Manic Miner and boulder Dash. I don't want to describe raster graphics in detail, because... its use is obvious, but I’ll tell you a couple of interesting ones approaches that are of great interest: Interactive graphics: In many older games, the question of character The properties of an object were decided by its color. Subsequently this has become unacceptable - it is very obvious and not beautiful. Therefore, the concept of interactive graphics arose. Together with each graphic object (its attributes) is stored the same number of bytes of interactive attributes (i.e. characterizing the properties of an object), how many color attributes. Somewhere in memory an area of size was allocated 768 bytes, where by analogy with color attributes interactive attributes were entered. Next question: what what's ahead of us? - solved very simply - enoughwas to look in this shadow attribute screen properties of the next familiar place and determine how in such situation to act (explode, award a bonus, etc.). I hope you get the main idea. 'Clashing' and the fight against it. Everyone knows for certain that the familiar places of points there is only one byte of attributes, which does not allow 'spread' your wings. The phenomenon of clashing occurs. Clashing overlay of attributes, i.e. for example, a white tank ran into green grass, in the area of something either the tank turned green or the grass turned white. There are several conclusions that should be recognized: 1. One of the colors when preparing images should be be black color. 2. In the overlay and background image, black One should have ink and the other paper. 3. The overlay image should be black paper, while the background one has ink. These three rules will help you get rid of problems clashing when superimposed by xor. Actually it should experiment with both mask and or overlay, but everyone can do it. 3D raster graphics: Sprites for such graphics are pre-drawn in any projection (isometric, cabinet) and adjust to each other according to or. Rule 4. If a sprite is superimposed on the background, then it’s better use xor, if the sprite is on a sprite, then or.Simplify the background image to a minimum, and from using refuse color palettes. Vector graphics: A very powerful vector graphics device is still weak used on Spectrum. Mostly it to us demonstrated in demos and intros. Serious programs domestic programmers using vector There are no graphics, because its use requires serious knowledge of stereometry, descriptive geometry, matrix algebra, etc., which I actually don’t know. On at this stage, everything I know is so limited and inaccessible to others, which I decided not to 'disclose' military secret' and modestly remain silent. Block graphics: Almost everywhere we can see block graphics. It MUST be in any program, because... font is already block graphics. It is obvious that most people The concept of block graphics is as necessary as an orange to a pig. But that's all Anyway, I'll tell you something useful: Creating three-dimensional effects in block graphics. The algorithm of work is obvious: Let's say we have a flat object consisting of cubes from which a shadow is cast. This object has a size of 4 x 4. @ @@ @ @@@@ Algorithm: A cycle of bypassing all blocks moving from the light source, i.e. if the source is on the left and above, then we move to the left to the right along the lines and from top to bottom.We check each block for the presence of a neighboring block in side away from the source. In our case it is right-down. If there is no block, then in its place is drawn shadow, with corresponding direction. This algorithm is universal, but in most cases you have determined in advance the location of the light source giving the shadow, therefore the algorithm is greatly simplified to a fairly easy one implementation. I hope I haven't burdened you too much with these pearls. In general, the source of this information is 'Applied graphics'. But due to the fact that this publication is a little oak, I chewed all those foggy thoughts that were there expressed. It is worth noting that this is not a graphics issue. exhausted. There are a huge number of tricky tricks storage, output, graphics compression. Everyone doesn't know them who. I suggest you write about those tricks and powerful techniques that you have dug up somewhere, regardless where, be it music. editor or simple converter. The only thing you shouldn't do is sit silently fold your arms and stare blankly at the monitor. It's quite possible that someone just lacks the technique with which you own but don't want to share. So, I encourage you to be active, tell us about What interesting things do you know that others don’t know? With the best wishes, SAV.