IVideoDriver request : draw2DPixel

[aanderse]

I took a look in a few of the video drivers and it looks like it would be fairly trivial to add a draw2DPixel function.
Would this be accepted in Irrlicht?

Thanks

[rogerborg]

I can't speak for the SVN devs, but I was looking for such a method recently and was surprised to find it missing.

Are you proposing to supply an implementation for a range of drivers? That would be ideal.

[aanderse]

rogerborg,

yeah having a virtual function added to IVideoDriver and then implemented in all drivers would be ideal.
as far as supplying the code to do that.... any volunteers to help me out?

[rogerborg]

Which drivers are you proposing to modify yourself?

[aanderse]

alright i took a quick look at the software drivers and the opengl driver. i'm at work right now and unable to actually test this, but i'll post the patch i made up now (and then test it at home).

will definitely need a volunteer for the directx implementation because i don't own a windows machine.

so here are 2 patch files, one for IVideoDriver, and the other for the opengl, software, and software2 driver:

Code: Select all

Index: IVideoDriver.h
===================================================================
--- IVideoDriver.h	(revision 1640)
+++ IVideoDriver.h	(working copy)
@@ -590,6 +590,12 @@
 					const core::position2d<s32>& end,
 					SColor color=SColor(255,255,255,255)) = 0;
 
+		//! Draws a pixel.
+		/** \param x: x coordinate of the pixel.
+		\param y: y coordinate of the pixel.
+		\param color: Color of the pixel to draw. */
+		virtual void drawPixel(u32 x, u32 y, const SColor &color) = 0;
+
 		//! Draws a non filled concyclic regular 2d polyon.
 		/** This method can be used to draw circles, but also
 		triangles, tetragons, pentagons, hexagons, heptagons, octagons,

Code: Select all

Index: COpenGLDriver.cpp
===================================================================
--- COpenGLDriver.cpp	(revision 1640)
+++ COpenGLDriver.cpp	(working copy)
@@ -1488,7 +1488,19 @@
 }
 
 
+//! Draws a pixel
+void COpenGLDriver::drawPixel(u32 x, u32 y, const SColor &color)
+{
+	disableTextures();
+	setRenderStates2DMode(color.getAlpha() < 255, false, false);
 
+	glBegin(GL_POINTS);
+	glColor4ub(color.getRed(), color.getGreen(), color.getBlue(), color.getAlpha());
+	glVertex2i(x, y);
+	glEnd();
+}
+
+
 bool COpenGLDriver::setTexture(u32 stage, const video::ITexture* texture)
 {
 	if (stage >= MaxTextureUnits)
Index: COpenGLDriver.h
===================================================================
--- COpenGLDriver.h	(revision 1640)
+++ COpenGLDriver.h	(working copy)
@@ -201,6 +201,9 @@
 					const core::position2d<s32>& end,
 					SColor color=SColor(255,255,255,255));
 
+		//! Draws a pixel
+		virtual void drawPixel(u32 x, u32 y, const SColor &color);
+
 		//! Draws a 3d line.
 		virtual void draw3DLine(const core::vector3df& start,
 					const core::vector3df& end,
Index: CSoftwareDriver.cpp
===================================================================
--- CSoftwareDriver.cpp	(revision 1640)
+++ CSoftwareDriver.cpp	(working copy)
@@ -813,7 +813,13 @@
 }
 
 
+//! Draws a pixel
+void CSoftwareDriver::drawPixel(u32 x, u32 y, const SColor &color)
+{
+	((CImage*)BackBuffer)->setPixel(x, y, color);
+}
 
+
 //! draw a 2d rectangle
 void CSoftwareDriver::draw2DRectangle(SColor color, const core::rect<s32>& pos,
 					const core::rect<s32>* clip)
Index: CSoftwareDriver.h
===================================================================
--- CSoftwareDriver.h	(revision 1640)
+++ CSoftwareDriver.h	(working copy)
@@ -83,6 +83,9 @@
 								const core::position2d<s32>& end,
 								SColor color=SColor(255,255,255,255));
 
+		//! Draws a pixel
+		virtual void drawPixel(u32 x, u32 y, const SColor &color);
+
 		//! \return Returns the name of the video driver. Example: In case of the Direct3D8
 		//! driver, it would return "Direct3D8.1".
 		virtual const wchar_t* getName() const;
Index: CSoftwareDriver2.cpp
===================================================================
--- CSoftwareDriver2.cpp	(revision 1640)
+++ CSoftwareDriver2.cpp	(working copy)
@@ -1579,6 +1579,13 @@
 }
 
 
+//! Draws a pixel
+void CBurningVideoDriver::drawPixel(u32 x, u32 y, const SColor &color)
+{
+	((CImage*)BackBuffer)->setPixel(x, y, color);
+}
+
+
 //! draw an 2d rectangle
 void CBurningVideoDriver::draw2DRectangle(SColor color, const core::rect<s32>& pos,
 									 const core::rect<s32>* clip)
Index: CSoftwareDriver2.h
===================================================================
--- CSoftwareDriver2.h	(revision 1640)
+++ CSoftwareDriver2.h	(working copy)
@@ -99,6 +99,9 @@
 					const core::position2d<s32>& end,
 					SColor color=SColor(255,255,255,255));
 
+		//! Draws a pixel
+		virtual void drawPixel(u32 x, u32 y, const SColor &color);
+
 		//! \return Returns the name of the video driver. Example: In case of the DirectX8
 		//! driver, it would return "Direct3D8.1".
 		virtual const wchar_t* getName() const;

ps. sorry if i haven't prepared the patch in the correct way, if not i'll fix it when i'm at home

[aanderse]

Ok I fixed an error or two I had made in my patches. I have tested them and everything appears to be working fine.

trivial test case:

Code: Select all

#include "irrlicht.h"

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

#ifdef _IRR_WINDOWS_
#pragma comment(lib, "Irrlicht.lib")
#pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
#endif

int main()
{
    IrrlichtDevice *device = createDevice( video::EDT_BURNINGSVIDEO, dimension2d<s32>(640, 480), 16, false, false, false, 0);
    
    if (!device)
        return 1;
    
    device->setWindowCaption(L"Hello World! - Irrlicht Engine Demo");
    
    IVideoDriver* driver = device->getVideoDriver();
    
    while(device->run())
    {
        driver->beginScene(true, true, SColor(255,100,101,140));
        for(u32 x = 0; x < 640; x++) {
            for(u32 y = 0; y < 480;) {
                driver->drawPixel(x, y, SColor(255, 255, 0, 255));
                y += 25;
            }
        }
        driver->endScene();
    }
    
    device->drop();
    
    return 0;
}

thanks

[rogerborg]

I can't speak for the SVN devs.

Heh. Heheheh. Or can I? Heeeeehahahahah.

[rogerborg]

Committed in SVN 1642. Many thanks for the API and implementations.

Test code follows:

Code: Select all

#include "irrlicht.h"

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

#ifdef _IRR_WINDOWS_
#pragma comment(lib, "Irrlicht.lib")
#pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
#endif


bool runTestWithDriver(E_DRIVER_TYPE driverType)
{
	IrrlichtDevice *device = createDevice( driverType, dimension2d<s32>(640, 480));
	if (!device)
		if(EDT_DIRECT3D8 == driverType || EDT_DIRECT3D9 == driverType)
			return true; // Might not be built in.
		else
			return false;
   
	IVideoDriver* driver = device->getVideoDriver();
	ISceneManager * smgr = device->getSceneManager();
	
	// Draw a cube to check that the pixels' alpha is working.
	ISceneNode * cube = smgr->addCubeSceneNode(50.f, 0, -1, vector3df(0, 0, 60));
	cube->setMaterialTexture(0, driver->getTexture("../../media/wall.bmp"));
	cube->setMaterialFlag(video::EMF_LIGHTING, false);
	(void)smgr->addCameraSceneNode();

	driver->beginScene(true, true, SColor(255,100,101,140));
	smgr->drawAll();

	// Test for out-of-range values as well as valid ones.
	for(s32 x = -10; x < 650; ++x)
	{
		s32 y = 480 * x / 640;
		driver->drawPixel((u32)x, (u32)y, SColor(255, 255 * x / 640, 255 * (640 - x) / 640, 0));
		y = 480 - y;
		driver->drawPixel((u32)x, (u32)y, SColor(255 * x / 640, 0, 255, 255));
	}

	driver->endScene();

	IImage * screenshot = driver->createScreenShot();
	bool result = true;

	if(screenshot)
	{
		stringc filename(driver->getName());
		filename += ".png";
		result = driver->writeImageToFile(screenshot, filename.c_str());
		screenshot->drop();

		stringc openFile("\"");
		openFile += filename;
		openFile += "\"";
		(void)system(openFile.c_str());
	}

	device->drop();

	return result;
}


int main()
{
	bool passed = true;

	passed &= runTestWithDriver(EDT_NULL);
	passed &= runTestWithDriver(EDT_SOFTWARE);
	passed &= runTestWithDriver(EDT_BURNINGSVIDEO);
	passed &= runTestWithDriver(EDT_OPENGL);
	passed &= runTestWithDriver(EDT_DIRECT3D8);
	passed &= runTestWithDriver(EDT_DIRECT3D9);
   
	return passed ? 0 : 1;
}

[aanderse]

thanks rogerborg, i appreciate you fixing it up, finishing it and getting it into svn