love2d.love/src/modules/graphics/opengl/Image.cpp

/**
* Copyright (c) 2006-2011 LOVE Development Team
*
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
*    claim that you wrote the original software. If you use this software
*    in a product, an acknowledgment in the product documentation would be
*    appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
*    misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
**/

#include "Image.h"

// STD
#include <cstring> // For memcpy

namespace love
{
namespace graphics
{
namespace opengl
{

	Image::Image(love::image::ImageData * data)
		: width((float)(data->getWidth())), height((float)(data->getHeight())), texture(0)
	{
		data->retain();
		this->data = data;

		memset(vertices, 255, sizeof(vertex)*4);

		vertices[0].x = 0; vertices[0].y = 0;
		vertices[1].x = 0; vertices[1].y = height;
		vertices[2].x = width; vertices[2].y = height;
		vertices[3].x = width; vertices[3].y = 0;

		vertices[0].s = 0; vertices[0].t = 0;
		vertices[1].s = 0; vertices[1].t = 1;
		vertices[2].s = 1; vertices[2].t = 1;
		vertices[3].s = 1; vertices[3].t = 0;

	}

	Image::~Image()
	{
		if(data != 0)
			data->release();
		unload();
	}

	float Image::getWidth() const
	{
		return width;
	}

	float Image::getHeight() const
	{
		return height;
	}

	const vertex * Image::getVertices() const
	{
		return vertices;
	}

	love::image::ImageData * Image::getData() const
	{
		return data;
	}

	void Image::getRectangleVertices(int x, int y, int w, int h, vertex * vertices) const
	{
		// Check upper.
		x = (x+w > (int)width) ? (int)width-w : x;
		y = (y+h > (int)height) ? (int)height-h : y;

		// Check lower.
		x = (x < 0) ? 0 : x;
		y = (y < 0) ? 0 : y;

		vertices[0].x = 0; vertices[0].y = 0;
		vertices[1].x = 0; vertices[1].y = (float)h;
		vertices[2].x = (float)w; vertices[2].y = (float)h;
		vertices[3].x = (float)w; vertices[3].y = 0;

		float tx = (float)x/width;
		float ty = (float)y/height;
		float tw = (float)w/width;
		float th = (float)h/height;

		vertices[0].s = tx; vertices[0].t = ty;
		vertices[1].s = tx; vertices[1].t = ty+th;
		vertices[2].s = tx+tw; vertices[2].t = ty+th;
		vertices[3].s = tx+tw; vertices[3].t = ty;
	}

	void Image::draw(float x, float y, float angle, float sx, float sy, float ox, float oy) const
	{
		static Matrix t;

		t.setTransformation(x, y, angle, sx, sy, ox, oy);
		drawv(t, vertices);
	}

	void Image::drawq(Quad * quad, float x, float y, float angle, float sx, float sy, float ox, float oy) const
	{
		static Matrix t;
		const vertex * v = quad->getVertices();

		t.setTransformation(x, y, angle, sx, sy, ox, oy);
		drawv(t, v);
	}

	void Image::setFilter(Image::Filter f)
	{
		GLint gmin, gmag;
		gmin = gmag = 0; // so that they're not used uninitialized

		switch(f.min)
		{
		case FILTER_LINEAR:
			gmin = GL_LINEAR;
			break;
		case FILTER_NEAREST:
			gmin = GL_NEAREST;
			break;
		default:
			break;
		}

		switch(f.mag)
		{
		case FILTER_LINEAR:
			gmag = GL_LINEAR;
			break;
		case FILTER_NEAREST:
			gmag = GL_NEAREST;
			break;
		default:
			break;
		}

		bind();

		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, gmin);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, gmag);
	}

	Image::Filter Image::getFilter() const
	{
		bind();

		GLint gmin, gmag;

		glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, &gmin);
		glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, &gmag);

		Image::Filter f;

		switch(gmin)
		{
		case GL_NEAREST:
			f.min = FILTER_NEAREST;
			break;
		case GL_LINEAR:
		default:
			f.min = FILTER_LINEAR;
			break;
		}

		switch(gmin)
		{
		case GL_NEAREST:
			f.mag = FILTER_NEAREST;
			break;
		case GL_LINEAR:
		default:
			f.mag = FILTER_LINEAR;
			break;
		}

		return f;
	}

	void Image::setWrap(Image::Wrap w)
	{
		GLint gs, gt;

		switch(w.s)
		{
		case WRAP_CLAMP:
			gs = GL_CLAMP_TO_EDGE;
			break;
		case WRAP_REPEAT:
		default:
			gs = GL_REPEAT;
			break;
		}

		switch(w.t)
		{
		case WRAP_CLAMP:
			gt = GL_CLAMP_TO_EDGE;
			break;
		case WRAP_REPEAT:
		default:
			gt = GL_REPEAT;
			break;
		}

		bind();

		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, gs);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, gt);
	}

	Image::Wrap Image::getWrap() const
	{
		bind();

		GLint gs, gt;

		glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, &gs);
		glGetTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, &gt);

		Wrap w;

		switch(gs)
		{
		case GL_CLAMP_TO_EDGE:
			w.s = WRAP_CLAMP;
			break;
		case GL_REPEAT:
		default:
			w.s = WRAP_REPEAT;
			break;
		}

		switch(gt)
		{
		case GL_CLAMP_TO_EDGE:
			w.t = WRAP_CLAMP;
			break;
		case GL_REPEAT:
		default:
			w.t = WRAP_REPEAT;
			break;
		}

		return w;
	}

	void Image::bind() const
	{
		if(texture != 0)
			glBindTexture(GL_TEXTURE_2D,texture);
	}

	bool Image::load()
	{
		return loadVolatile();
	}

	void Image::unload()
	{
		return unloadVolatile();
	}

	bool Image::loadVolatile()
	{
		glGenTextures(1,(GLuint*)&texture);
		glBindTexture(GL_TEXTURE_2D, texture);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		
		float p2width = next_p2(width);
		float p2height = next_p2(height);
		float t = width/p2width;
		float s = height/p2height;
		
		vertices[1].t = t;
		vertices[2].t = t;
		vertices[2].s = s;
		vertices[3].s = s;

		glTexImage2D(GL_TEXTURE_2D,
			0,
			GL_RGBA8,
			(GLsizei)p2width,
			(GLsizei)p2height,
			0,
			GL_RGBA,
			GL_UNSIGNED_BYTE,
			0);
			
		glTexSubImage2D(GL_TEXTURE_2D,
			0,
			0,
			0,
			(GLsizei)width,
			(GLsizei)height,
			GL_RGBA,
			GL_UNSIGNED_BYTE,
			data->getData());

		setFilter(settings.filter);
		setWrap(settings.wrap);

		return true;
	}

	void Image::unloadVolatile()
	{
		settings.filter = getFilter();
		settings.wrap = getWrap();
		// Delete the hardware texture.
		if(texture != 0)
		{
			glDeleteTextures(1, (GLuint*)&texture);
			texture = 0;
		}
	}

	void Image::drawv(const Matrix & t, const vertex * v) const
	{
		bind();

		glPushMatrix();

		glMultMatrixf((const GLfloat*)t.getElements());

		glEnableClientState(GL_VERTEX_ARRAY);
		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
		glVertexPointer(2, GL_FLOAT, sizeof(vertex), (GLvoid*)&v[0].x);
		glTexCoordPointer(2, GL_FLOAT, sizeof(vertex), (GLvoid*)&v[0].s);
		glDrawArrays(GL_QUADS, 0, 4);
		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		glDisableClientState(GL_VERTEX_ARRAY);

		glPopMatrix();
	}

} // opengl
} // graphics
} // love