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diff --git a/ipl/gpacks/htetris/implement.html b/ipl/gpacks/htetris/implement.html new file mode 100644 index 0000000..9392390 --- /dev/null +++ b/ipl/gpacks/htetris/implement.html @@ -0,0 +1,63 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN"> +<!--NewPage--> +<html> +<head> +<title>htetris documentation</title> +</head> +<body> +<h1> +<center>User Manual For htetris Version 1.0</center> +<center>Henrik Sandin 1999</center> +</h1> +<hr> +<a href="http://lww.CS.Arizona.EDU:80/~henriks/htetrisdoc.html">Main page</a> +<h2>Implementation details</h2><br> +<font size="5"> +The bricks are represented with matrix structures in the game as well as +the editor. An element in such a matrix represents one square in a brick. +A matrix is never larger than the actual rectangle which constitutes the +size of a brick which is measured in number of squares wide and high +respectively.<br> +In the editor, a brick-matrix consists of ones and zeros where a one +represents a colored square and a zero represents an uncolored (black, since +the backgroud of the edit pane is black) square. +A string representation of such matrices is used when they are saved to file.<br> +When a brick is used in the game, the brick-matrix elements plays a different +role. The area where the bricks fall also has a matrix representation where +every element, just like the brick matrices in the editor context contains +one or zero, one representing a position where a brick-square is permanently +stuck and zero representing a position that is "free".<br> +<br> +When a brick is shown and falling, its matrix conceptually resides on top of +the background matrix. At all times a brick-matrix keeps updated information +on where a particular square is as well as if that square is colored or not. +A brick-matrix element contains a record which in turn contains information +about the current row and column coordinates of the background matrix and +whether that square is colored or should be drawn transparent (not drawn). +When a brick changes position (falls one step or is moved to the left or +to the right), its matrix is updated accordingly.<br> +When a brick is considered to be stuck somewhere, the background matrix is +updated by looking at the current information in the current brick-matrix. +The determining of whether a brick is stuck or can/can not be moved, is done +by looking at the surrounding elements relative to a brick's current +position in the background matrix. +An element in a brick matrix which is market as "colored" can never be +located "on top" of an element in the background matrix which contains a one.<br> +<br> +The actual drawing and erasing of the bricks is based on the background matrix +indeces where a brick currently resides. +A brick square has a constant width and height, so it is only a matter of +multiplying that constant number of pixels by the matrix row or column number +to determining where the brick image should be drawn.<br> +<br> +Graphically, a brick is a rectangular image(string) which is drawn using the +procedure <b>DrawImage()</b> which support transparency in drawing. +This is useful since bricks are shaped as they are.<br> +Erasing of a brick is done by a series of <b>EraseArea()</b> calls each of +which is erasing one square of the brick. This is a little bit slow but is +necessary to prevent already stuck bricks from being overwritten. +This might happen if a falling brick is erased by clearing one single rectangle +covering the whole brick when it is close enough to already stuck ones. +</font> +</body> +</html> |