Function draw

Sming/Libraries/AnimatedGIF/src/AnimatedGifTask.cpp:20–120

#include "AnimatedGifTask.h"

void draw(GIFDRAW* pDraw)
{
	auto surface = static_cast<Graphics::Surface*>(pDraw->pUser);
	if(surface == nullptr) {
		return;
	}

	const auto& tftSize = surface->getSize();
	const int DISPLAY_WIDTH = tftSize.w;
	const int DISPLAY_HEIGHT = tftSize.h;

	auto pixelFormat = surface->getPixelFormat();
	auto bytesPerPixel = Graphics::getBytesPerPixel(pixelFormat);

	uint16_t usTemp[DISPLAY_WIDTH];
	Graphics::SharedBuffer buffer(bytesPerPixel * DISPLAY_WIDTH);

	int iWidth = pDraw->iWidth;
	if(iWidth + pDraw->iX > DISPLAY_WIDTH) {
		iWidth = DISPLAY_WIDTH - pDraw->iX;
	}
	const uint16_t* usPalette = pDraw->pPalette;
	int y = pDraw->iY + pDraw->y; // current line
	if(y >= DISPLAY_HEIGHT || pDraw->iX >= DISPLAY_WIDTH || iWidth < 1) {
		return;
	}

	auto s = pDraw->pPixels;
	if(pDraw->ucDisposalMethod == 2) // restore to background color
	{
		for(int x = 0; x < iWidth; x++) {
			if(s[x] == pDraw->ucTransparent) {
				s[x] = pDraw->ucBackground;
			}
		}
		pDraw->ucHasTransparency = 0;
	}

	// Apply the new pixels to the main image
	if(pDraw->ucHasTransparency) // if transparency used
	{
		uint8_t ucTransparent = pDraw->ucTransparent;
		uint8_t* pEnd = s + iWidth;
		int x = 0;
		int iCount = 0; // count non-transparent pixels
		while(x < iWidth) {
			uint8_t c = ucTransparent - 1;
			uint16_t* d = usTemp;
			while(c != ucTransparent && s < pEnd) {
				c = *s++;
				if(c == ucTransparent) {
					// done, stop: back up to treat it like transparent
					s--;
				} else {
					// opaque
					*d++ = __builtin_bswap16(usPalette[c]);
					iCount++;
				}