diff options
Diffstat (limited to 'html/en/drv/irgb.html')
| -rw-r--r-- | html/en/drv/irgb.html | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/html/en/drv/irgb.html b/html/en/drv/irgb.html new file mode 100644 index 0000000..3ab71f4 --- /dev/null +++ b/html/en/drv/irgb.html @@ -0,0 +1,117 @@ +<!doctype HTML PUBLIC "-//IETF//DTD HTML//EN"> +<html> + +<head> +<meta http-equiv="Content-Language" content="en-us"> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> +<title>CD_IMAGERGB</title> +<link rel="stylesheet" type="text/css" href="../../style.css"> +</head> + +<body> + +<h2>CD_IMAGERGB - RGB Client Image Driver (cdirgb.h)</h2> + + <p>This driver allows access to a Client Image, an imaged based in RGB colors with 24 + or 32 bits per pixel (8 per channel). + It is used to implement high-quality offscreen drawings, but is slower than the Server Image version. In fact, it is a + rasterizer, that is, it converts vector primitives into a raster representation. All primitives are implemented by the + library and are not system-dependent (the primitives of the Server Image version are system-dependent).</p> + +<h3>Use</h3> + + <p>The canvas is created by means of a call to the function <font face="Courier"> + <a href="../func/init.html#cdCreateCanvas"><strong>cdCreateCanvas</strong></a>(CD_IMAGERGB, + Data)</font>, after which other functions in the CD library can be called as usual. The function creates an RGB image, + and then a CD canvas. The <font face="Courier">Data</font> parameter string has the following format:</p> + + <pre><em>"width<strong>x</strong>height [r g b] -<strong>r</strong>[resolution]"</em> in C "<em><strong><tt>%dx%d %p %p %p -r%g" +or +</tt></strong>"width<strong>x</strong>height [r g b a] -<strong>r</strong>[resolution] -<strong>a</strong>"</em> in C "<em><strong><tt>%dx%d %p %p %p %p -r%g -a"</tt></strong></em></pre> + + <p>It must include the canvas' dimensions.<font face="Courier"> Width</font> and <font face="Courier">height</font> + are provided in pixels (note the lowercase "x" between them). As an option, you can specify the buffers to be used by + the driver, so that you can draw over an existing image. The resolution can be defined with parameter + <font face="Courier">-r</font>; its default value is "3.78 pixels/mm" (96 DPI). </p> +<p>When the parameter -a is specified an alpha channel will be added to the +canvas underlying image. All primitives will be composed using an over operator +if the foreground or background colors have alpha components. This channel is +initialized with transparent (0). The other channels are initialized with white +(255, 255, 255). After drawing in the RGBA image the resulting alpha channel can +be used to compose the image in another canvas.</p> +<p>All channels are initialized only when allocated internally by the driver. +They are not initialized when allocated by the application.</p> + <p>Any amount of such canvases may exist simultaneously. It is important to note that a call to function + <a href="../func/init.html#cdKillCanvas"><strong>cdKillCanvas</strong></a> is required to + release internal allocated memory.</p> + <p>In Lua, the canvas can be created in two ways: with an already defined image or without it. With an image, an RGB + image must be passed as parameter, created by functions <strong> + <a href="../func/client.html#cdCreateImageRGB">cd.CreateImageRGB</a>,</strong> + <strong><a href="../func/client.html#cdCreateImageRGBA">cd.CreateImageRGBA</a></strong> or <strong> + <a href="../func/client.html#cdCreateBitmap">cd.CreateBitmap</a></strong> + in Lua. The resolution must be passed in an extra parameter after the image.</p> + +<h3>Exclusive Functions</h3> + +<h4><font face="Courier">cd.ImageRGB(canvas: cdCanvas) -> (imagergb: cdImageRGB +or cdImageRGBA) [in Lua]<br> +cd.ImageRGBBitmap(canvas: cdCanvas) -> (bitmap: cdBitmap) [in Lua]</font></h4> + + <p>Returns the canvas' internal image.</p> + +<h3>Behavior of Functions</h3> + + <p>All primitives are from the Simulation driver, see the <a href="sim.html">Simulation</a> driver's documentation for + further information.</p> + +<h4>Control</h4> +<ul> + <li><a href="../func/control.html#cdFlush"><font face="Courier"><strong>Flush</strong></font></a>: + does nothing.</li> + <li><a href="../func/other.html#cdPlay"><font face="Courier"><strong>Play</strong></font></a>: + does nothing, returns <font face="Courier">CD_ERROR</font>. </li> +</ul> +<h4>Coordinate System and Clipping </h4> +<ul> + <li><a href="../func/coordinates.html#cdUpdateYAxis"><font face="Courier"> + <strong>UpdateYAxis</strong></font></a>: does nothing. The axis orientation is the same as the CD library's.</li> +</ul> +<h4>Colors </h4> +<ul> + <li><a href="../func/color.html#cdGetColorPlanes"><font face="Courier"> + <strong> + GetColorPlanes</strong></font></a>: returns 24 if no alpha, returns 32 if + exists an alpha channel.</li> + <li><a href="../func/color.html#cdPalette"><font face="Courier"><strong>Palette</strong></font></a>: + does nothing.</li> + <li><a href="../func/attributes.html#cdForeground"><font face="Courier"> + <strong> + Foreground</strong></font></a> & + <a href="../func/attributes.html#cdBackground"> + <font face="Courier"><strong>Background</strong></font></a>: accepts the transparency information encoded in the + color.</li> +</ul> +<h4>Exclusive Attributes</h4> +<ul> + <li>"<strong><font face="Courier">REDIMAGE</font></strong>", "<strong><font face="Courier">GREENIMAGE</font></strong>", + "<strong><font face="Courier">BLUEIMAGE</font></strong>", "<span style="font-family: Courier"><strong>ALPHA</strong></span><strong><font face="Courier">IMAGE</font></strong>": return the respective pointers of the canvas image (read-only). Not accessible in Lua.</li> +</ul> + +<ul> + <li>"<b><font face="Courier">ANTIALIAS</font></b>": controls the use of anti-aliasing + for line primitives. Assumes values "1" (active) and "0" (inactive). Default value: "1". + Notice that text is always antialiased.</li> +</ul> + +<ul> + <li>"<b><font face="Courier">ROTATE</font></b>": allows the usage of 1 + angle and 1 coordinate (x, y), that define a global rotation transformation + centered in the specified coordinate. Use 1 real and 2 integer values inside a + string ("%g %d %d" = angle x y). In this driver will change the + current transformation matrix, if removed will reset the current + transformation matrix.</li> +</ul> + +</body> + +</html>
\ No newline at end of file |