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#ActualJossos

Posted 05 April 2013 - 03:47 AM

So I want to draw a minimap for my app pixel-by-pixel, but I have no idea how, and google has yielded no results (mainly stuff loading already existing images - I already know how to do)

 

I'll place my minimap Class for you to peruse and I hope someone can help me. It's the syntax I don't know about. (there's a bit of opengl in here too, but it's mostly an sdl question).

class smMINIMAP
{
private:
	float xPos, yPos, width, height;
	smMAP* mapRef;
	SDL_Surface *map_img;

	void PutPixel(int x, int y, int color);
public:
	smMINIMAP(smMAP& map);
	~smMINIMAP();

	void Draw(int x, int y, int w = 200, int h = 200);
};
smMINIMAP::smMINIMAP(smMAP& map)
{
	*mapRef = map;

	map_img = SDL_CreateRGBSurface(0, mapRef->getWidth(), mapRef->getLength(), 32, 0, 0, 0, 0);
}

smMINIMAP::~smMINIMAP()
{
	delete mapRef;
}

void smMINIMAP::Draw(int x, int y, int w, int h)
{
	Uint32* pixels = (Uint32*)map_img->pixels;

	for (int w = 0; w < mapRef->getWidth(); w++)
	{
		for (int l = 0; l < mapRef->getLength(); l++)
		{
			PutPixel(w, l, 0xff0000);
		}
	}

	glEnable(GL_TEXTURE_2D);

	GLuint ret;

	glGenTextures(1, &ret);
	glBindTexture(GL_TEXTURE_2D, ret);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, map_img->w, map_img->h, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, map_img->pixels);

	glBegin(GL_QUADS);
		glTexCoord2f(0, 0); glVertex2f(x,     y);
		glTexCoord2f(1, 0); glVertex2f(x + w, y);
		glTexCoord2f(1, 1); glVertex2f(x + w, y + h);
		glTexCoord2f(0, 1); glVertex2f(x,     y + h);
	glEnd();
}

void smMINIMAP::PutPixel(int x, int y, int color)
{
	unsigned int* ptr = (unsigned int*)map_img->pixels;
	int lineoffset = y * (map_img->pitch / 4);
	ptr[lineoffset + x] = color;
}

 

 

smMAP is just a 2d array of tiles. It's irrelevant right now, as I just want to make each pixel red to get something on the screen - then I can colorize it.

 

Help is greatly appreciated!


#1Jossos

Posted 05 April 2013 - 03:27 AM

So I want to draw a minimap for my app, but I have no idea how, and google has yielded no results (mainly stuff loading already existing images - I already know how to do)

 

I'll place my minimap Class for you to peruse and I hope someone can help me. It's the syntax I don't know about. (there's a bit of opengl in here too, but it's mostly an sdl question).

class smMINIMAP
{
private:
	float xPos, yPos, width, height;
	smMAP* mapRef;
	SDL_Surface *map_img;

	void PutPixel(int x, int y, int color);
public:
	smMINIMAP(smMAP& map);
	~smMINIMAP();

	void Draw(int x, int y, int w = 200, int h = 200);
};
smMINIMAP::smMINIMAP(smMAP& map)
{
	*mapRef = map;

	map_img = SDL_CreateRGBSurface(0, mapRef->getWidth(), mapRef->getLength(), 32, 0, 0, 0, 0);
}

smMINIMAP::~smMINIMAP()
{
	delete mapRef;
}

void smMINIMAP::Draw(int x, int y, int w, int h)
{
	Uint32* pixels = (Uint32*)map_img->pixels;

	for (int w = 0; w < mapRef->getWidth(); w++)
	{
		for (int l = 0; l < mapRef->getLength(); l++)
		{
			PutPixel(w, l, 0xff0000);
		}
	}

	glEnable(GL_TEXTURE_2D);

	GLuint ret;

	glGenTextures(1, &ret);
	glBindTexture(GL_TEXTURE_2D, ret);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, map_img->w, map_img->h, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, map_img->pixels);

	glBegin(GL_QUADS);
		glTexCoord2f(0, 0); glVertex2f(x,     y);
		glTexCoord2f(1, 0); glVertex2f(x + w, y);
		glTexCoord2f(1, 1); glVertex2f(x + w, y + h);
		glTexCoord2f(0, 1); glVertex2f(x,     y + h);
	glEnd();
}

void smMINIMAP::PutPixel(int x, int y, int color)
{
	unsigned int* ptr = (unsigned int*)map_img->pixels;
	int lineoffset = y * (map_img->pitch / 4);
	ptr[lineoffset + x] = color;
}

 

 

smMAP is just a 2d array of tiles. It's irrelevant right now, as I just want to make each pixel red to get something on the screen - then I can colorize it.

 

Help is greatly appreciated!


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