irrlicht/examples/06.2DGraphics/main.cpp
cutealien 8310a3fbad Avoid warning and make local variable lower-case.
git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6000 dfc29bdd-3216-0410-991c-e03cc46cb475
2019-12-12 16:32:41 +00:00

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5.6 KiB
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/** Example 006 2D Graphics
This tutorial shows how to do 2d graphics with the Irrlicht Engine.
It shows how to draw images, keycolor based sprites,
transparent rectangles, and different fonts. You may consider
this useful if you want to make a 2d game with the engine, or if
you want to draw a cool interface or head up display for your 3d game.
As always, I include the header files, use the irr namespace,
and tell the linker to link with the .lib file.
*/
#include <irrlicht.h>
#include "driverChoice.h"
#include "exampleHelper.h"
using namespace irr;
#ifdef _MSC_VER
#pragma comment(lib, "Irrlicht.lib")
#endif
/*
At first, we let the user select the driver type, then start up the engine, set
a caption, and get a pointer to the video driver.
*/
int main()
{
// ask user for driver
video::E_DRIVER_TYPE driverType=driverChoiceConsole();
if (driverType==video::EDT_COUNT)
return 1;
// create device
IrrlichtDevice *device = createDevice(driverType,
core::dimension2d<u32>(512, 384));
if (device == 0)
return 1; // could not create selected driver.
device->setWindowCaption(L"Irrlicht Engine - 2D Graphics Demo");
video::IVideoDriver* driver = device->getVideoDriver();
const io::path mediaPath = getExampleMediaPath();
/*
All 2d graphics in this example are put together into one texture,
2ddemo.png. Because we want to draw colorkey based sprites, we need to
load this texture and tell the engine, which part of it should be
transparent based on a colorkey.
In this example, we don't tell it the color directly, we just say "Hey
Irrlicht Engine, you'll find the color I want at position (0,0) on the
texture.". Instead, it would be also possible to call
driver->makeColorKeyTexture(images, video::SColor(0,0,0,0)), to make
e.g. all black pixels transparent. Please note that
makeColorKeyTexture just creates an alpha channel based on the color.
*/
video::ITexture* images = driver->getTexture(mediaPath + "2ddemo.png");
driver->makeColorKeyTexture(images, core::position2d<s32>(0,0));
/*
To be able to draw some text with two different fonts, we first load
them. OK, we load just one. As the first font we just use the default
font which is built into the engine. Also, we define two rectangles
which specify the position of the images of the red imps (little flying
creatures) in the texture.
*/
gui::IGUIFont* font = device->getGUIEnvironment()->getBuiltInFont();
gui::IGUIFont* font2 =
device->getGUIEnvironment()->getFont(mediaPath + "fonthaettenschweiler.bmp");
core::rect<s32> imp1(349,15,385,78);
core::rect<s32> imp2(387,15,423,78);
/*
Prepare a nicely filtering 2d render mode for special cases.
*/
driver->getMaterial2D().TextureLayer[0].BilinearFilter=true;
driver->getMaterial2D().AntiAliasing=video::EAAM_FULL_BASIC;
/*
Everything is prepared, now we can draw everything in the draw loop,
between the begin scene and end scene calls. In this example, we are
just doing 2d graphics, but it would be no problem to mix them with 3d
graphics. Just try it out, and draw some 3d vertices or set up a scene
with the scene manager and draw it.
*/
while(device->run() && driver)
{
if (device->isWindowActive())
{
u32 time = device->getTimer()->getTime();
driver->beginScene(video::ECBF_COLOR | video::ECBF_DEPTH, video::SColor(255,120,102,136));
/*
First, we draw 3 sprites, using the alpha channel we
created with makeColorKeyTexture. The last parameter
specifies that the drawing method should use this alpha
channel. The last-but-one parameter specifies a
color, with which the sprite should be colored.
(255,255,255,255) is full white, so the sprite will
look like the original. The third sprite is drawn
with the red channel modulated based on the time.
*/
// draw fire & dragons background world
driver->draw2DImage(images, core::position2d<s32>(50,50),
core::rect<s32>(0,0,342,224), 0,
video::SColor(255,255,255,255), true);
// draw flying imp
driver->draw2DImage(images, core::position2d<s32>(164,125),
(time/500 % 2) ? imp1 : imp2, 0,
video::SColor(255,255,255,255), true);
// draw second flying imp with color cycle
driver->draw2DImage(images, core::position2d<s32>(270,105),
(time/500 % 2) ? imp1 : imp2, 0,
video::SColor(255,(time) % 255,255,255), true);
/*
Drawing text is really simple. The code should be self
explanatory.
*/
// draw some text
if (font)
font->draw(L"This demo shows that Irrlicht is also capable of drawing 2D graphics.",
core::rect<s32>(130,10,300,50),
video::SColor(255,255,255,255));
// draw some other text
if (font2)
font2->draw(L"Also mixing with 3d graphics is possible.",
core::rect<s32>(130,20,300,60),
video::SColor(255,time % 255,time % 255,255));
/*
Next, we draw the Irrlicht Engine logo (without
using a color or an alpha channel). Since we slightly scale
the image we use the prepared filter mode.
*/
driver->enableMaterial2D();
driver->draw2DImage(images, core::rect<s32>(10,10,108,48),
core::rect<s32>(354,87,442,118));
driver->enableMaterial2D(false);
/*
Finally draw a half-transparent rect under the mouse cursor.
*/
core::position2d<s32> m = device->getCursorControl()->getPosition();
driver->draw2DRectangle(video::SColor(100,255,255,255),
core::rect<s32>(m.X-20, m.Y-20, m.X+20, m.Y+20));
driver->endScene();
}
}
device->drop();
return 0;
}
/*
That's all. I hope it was not too difficult.
**/