Changeset - r13424:6b5658ade4b5
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master
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smatz - 15 years ago 2009-11-01 20:54:21
smatz@openttd.org
(svn r17943) -Change: use 24bpp BMP format instead of 32bpp for screenshots. Saves space and is supported by more image viewers
1 file changed with 82 insertions and 55 deletions:
0 comments (0 inline, 0 general)
src/screenshot.cpp
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@@ -46,6 +46,7 @@ struct ScreenshotFormat {
 
#pragma pack(push, 1)
 
#endif
 

	
 
/** BMP File Header (stored in little endian) */
 
struct BitmapFileHeader {
 
	uint16 type;
 
	uint32 size;
 
@@ -58,6 +59,7 @@ assert_compile(sizeof(BitmapFileHeader) 
 
#pragma pack(pop)
 
#endif
 

	
 
/** BMP Info Header (stored in little endian) */
 
struct BitmapInfoHeader {
 
	uint32 size;
 
	int32 width, height;
 
@@ -66,47 +68,63 @@ struct BitmapInfoHeader {
 
};
 
assert_compile(sizeof(BitmapInfoHeader) == 40);
 

	
 
/** Format of palette data in BMP header */
 
struct RgbQuad {
 
	byte blue, green, red, reserved;
 
};
 
assert_compile(sizeof(RgbQuad) == 4);
 

	
 
/* generic .BMP writer */
 
/** Pixel data in 24bpp BMP */
 
struct RgbTriplet {
 
	byte b, g, r;
 
};
 
assert_compile(sizeof(RgbTriplet) == 3);
 

	
 
/**
 
 * Generic .BMP writer
 
 * @param name file name including extension
 
 * @param callb callback used for gathering rendered image
 
 * @param userdata parameters forwarded to #callb
 
 * @param w width in pixels
 
 * @param h height in pixels
 
 * @param pixelformat bits per pixel
 
 * @param paletter colour paletter (for 8bpp mode)
 
 * @return was everything ok?
 
 */
 
static bool MakeBmpImage(char *name, ScreenshotCallback *callb, void *userdata, uint w, uint h, int pixelformat, const Colour *palette)
 
{
 
	BitmapFileHeader bfh;
 
	BitmapInfoHeader bih;
 
	RgbQuad rq[256];
 
	FILE *f;
 
	uint i, padw;
 
	uint n, maxlines;
 
	uint pal_size = 0;
 
	uint bpp = pixelformat / 8;
 
	uint bpp; // bytes per pixel
 
	switch (pixelformat) {
 
		case 8:  bpp = 1; break;
 
		/* 32bpp mode is saved as 24bpp BMP */
 
		case 32: bpp = 3; break;
 
		/* Only implemented for 8bit and 32bit images so far */
 
		default: return false;
 
	}
 

	
 
	/* only implemented for 8bit and 32bit images so far. */
 
	if (pixelformat != 8 && pixelformat != 32) return false;
 

	
 
	f = fopen(name, "wb");
 
	FILE *f = fopen(name, "wb");
 
	if (f == NULL) return false;
 

	
 
	/* each scanline must be aligned on a 32bit boundary */
 
	padw = w;
 
	if (pixelformat == 8) padw = Align(padw, 4);
 
	/* Each scanline must be aligned on a 32bit boundary */
 
	uint bytewidth = Align(w * bpp, 4); // bytes per line in file
 

	
 
	if (pixelformat == 8) pal_size = sizeof(RgbQuad) * 256;
 
	/* Size of palette. Only present for 8bpp mode */
 
	uint pal_size = pixelformat == 8 ? sizeof(RgbQuad) * 256 : 0;
 

	
 
	/* setup the file header */
 
	/* Setup the file header */
 
	BitmapFileHeader bfh;
 
	bfh.type = TO_LE16('MB');
 
	bfh.size = TO_LE32(sizeof(bfh) + sizeof(bih) + pal_size + padw * h * bpp);
 
	bfh.size = TO_LE32(sizeof(BitmapFileHeader) + sizeof(BitmapInfoHeader) + pal_size + bytewidth * h);
 
	bfh.reserved = 0;
 
	bfh.off_bits = TO_LE32(sizeof(bfh) + sizeof(bih) + pal_size);
 
	bfh.off_bits = TO_LE32(sizeof(BitmapFileHeader) + sizeof(BitmapInfoHeader) + pal_size);
 

	
 
	/* setup the info header */
 
	/* Setup the info header */
 
	BitmapInfoHeader bih;
 
	bih.size = TO_LE32(sizeof(BitmapInfoHeader));
 
	bih.width = TO_LE32(w);
 
	bih.height = TO_LE32(h);
 
	bih.planes = TO_LE16(1);
 
	bih.bitcount = TO_LE16(pixelformat);
 
	bih.bitcount = TO_LE16(bpp * 8);
 
	bih.compression = 0;
 
	bih.sizeimage = 0;
 
	bih.xpels = 0;
 
@@ -114,57 +132,66 @@ static bool MakeBmpImage(char *name, Scr
 
	bih.clrused = 0;
 
	bih.clrimp = 0;
 

	
 
	/* Write file header and info header */
 
	if (fwrite(&bfh, sizeof(bfh), 1, f) != 1 || fwrite(&bih, sizeof(bih), 1, f) != 1) {
 
		fclose(f);
 
		return false;
 
	}
 

	
 
	if (pixelformat == 8) {
 
		/* convert the palette to the windows format */
 
		for (i = 0; i != 256; i++) {
 
		/* Convert the palette to the windows format */
 
		RgbQuad rq[256];
 
		for (uint i = 0; i < 256; i++) {
 
			rq[i].red   = palette[i].r;
 
			rq[i].green = palette[i].g;
 
			rq[i].blue  = palette[i].b;
 
			rq[i].reserved = 0;
 
		}
 
	}
 

	
 
	/* write file header and info header and palette */
 
	if (fwrite(&bfh, sizeof(bfh), 1, f) != 1 || fwrite(&bih, sizeof(bih), 1, f) != 1) {
 
		fclose(f);
 
		return false;
 
	}
 
	if (pixelformat == 8 && fwrite(rq, sizeof(rq), 1, f) != 1) {
 
		fclose(f);
 
		return false;
 
		/* Write the palette */
 
		if (fwrite(rq, sizeof(rq), 1, f) != 1) {
 
			fclose(f);
 
			return false;
 
		}
 
	}
 

	
 
	/* use by default 64k temp memory */
 
	maxlines = Clamp(65536 / padw, 16, 128);
 
	/* Try to use 64k of memory, store between 16 and 128 lines */
 
	uint maxlines = Clamp(65536 / (w * pixelformat / 8), 16, 128); // number of lines per iteration
 

	
 
	/* now generate the bitmap bits */
 
	uint8 *buff = CallocT<uint8>(padw * maxlines * bpp); // by default generate 128 lines at a time.
 
	uint8 *buff = MallocT<uint8>(maxlines * w * pixelformat / 8); // buffer which is rendered to
 
	uint8 *line = AllocaM(uint8, bytewidth); // one line, stored to file
 
	memset(line, 0, bytewidth);
 

	
 
	/* start at the bottom, since bitmaps are stored bottom up. */
 
	/* Start at the bottom, since bitmaps are stored bottom up */
 
	do {
 
		/* determine # lines */
 
		n = min(h, maxlines);
 
		uint n = min(h, maxlines);
 
		h -= n;
 

	
 
		/* render the pixels */
 
		callb(userdata, buff, h, padw, n);
 
		/* Render the pixels */
 
		callb(userdata, buff, h, w, n);
 

	
 
#if TTD_ENDIAN == TTD_BIG_ENDIAN
 
		if (pixelformat == 32) {
 
			/* Data stored in BMP are always little endian,
 
			 * but we have big endian data in buffer */
 
			uint32 *buff32 = (uint32 *)buff;
 
			for (i = 0; i < padw * n; i++) buff32[i] = BSWAP32(buff32[i]);
 
		}
 
#endif /* TTD_ENDIAN == TTD_BIG_ENDIAN */
 

	
 
		/* write each line */
 
		while (n)
 
			if (fwrite(buff + (--n) * padw * bpp, padw * bpp, 1, f) != 1) {
 
		/* Write each line */
 
		while (n-- != 0) {
 
			if (pixelformat == 8) {
 
				/* Move to 'line', leave last few pixels in line zeroed */
 
				memcpy(line, buff + n * w, w);
 
			} else {
 
				/* Convert from 'native' 32bpp to BMP-like 24bpp.
 
				 * Works for both big and little endian machines */
 
				Colour *src = ((Colour *)buff) + n * w;
 
				RgbTriplet *dst = (RgbTriplet *)line;
 
				for (uint i = 0; i < w; i++) {
 
					dst[i].r = src[i].r;
 
					dst[i].g = src[i].g;
 
					dst[i].b = src[i].b;
 
				}
 
			}
 
			/* Write to file */
 
			if (fwrite(line, bytewidth, 1, f) != 1) {
 
				free(buff);
 
				fclose(f);
 
				return false;
 
			}
 
		}
 
	} while (h != 0);
 

	
 
	free(buff);
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