Initial commit

vendor/librw/src/bmp.cpp

@@ -0,0 +1,284 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#include "rwbase.h"
+#include "rwerror.h"
+#include "rwplg.h"
+#include "rwpipeline.h"
+#include "rwobjects.h"
+#include "rwengine.h"
+
+#define PLUGIN_ID 0
+
+namespace rw {
+
+// NB: this has padding and cannot be streamed directly!
+struct BMPheader
+{
+	uint16 magic;
+	uint32 size;
+	uint16 reserved[2];
+	uint32 offset;
+
+	bool32 read(Stream *stream);
+	void write(Stream *stream);
+};
+
+// This one is aligned and can be streamed directly
+struct DIBheader
+{
+	uint32 headerSize;
+	int32 width;
+	int32 height;
+	int16 numPlanes;
+	int16 depth;
+	uint32 compression;
+	uint32 imgSize;
+	int32 hres;
+	int32 vres;
+	int32 paletteLen;
+	int32 numImportant;
+	// end of 40 btyes
+
+	uint32 rmask, gmask, bmask, amask;
+};
+
+bool32
+BMPheader::read(Stream *stream)
+{
+	magic = stream->readU16();
+	size = stream->readU32();
+	reserved[0] = stream->readU16();
+	reserved[1] = stream->readU16();
+	offset = stream->readU32();
+	return magic == 0x4D42;
+}
+
+void
+BMPheader::write(Stream *stream)
+{
+
+	stream->writeU16(magic);
+	stream->writeU32(size);
+	stream->writeU16(reserved[0]);
+	stream->writeU16(reserved[1]);
+	stream->writeU32(offset);
+}
+
+Image*
+readBMP(const char *filename)
+{
+	ASSERTLITTLE;
+	Image *image;
+	uint32 length;
+	uint8 *data;
+	StreamMemory file;
+	int i, x, y;
+
+	bool32 noalpha;
+	int pad;
+
+	data = getFileContents(filename, &length);
+	if(data == nil)
+		return nil;
+	file.open(data, length);
+
+	/* read headers */
+	BMPheader bmp;
+	DIBheader dib;
+	if(!bmp.read(&file))
+		goto lose;
+	file.read8(&dib, sizeof(dib));
+	file.seek(dib.headerSize-sizeof(dib));	// skip the part of the header we're ignoring
+	if(dib.headerSize <= 16){
+		dib.compression = 0;
+		dib.paletteLen = 0;
+	}
+
+	noalpha = true;
+
+	// Recognize 32 bit formats
+	if(dib.compression == 3){
+		if(dib.rmask != 0xFF0000 ||
+		   dib.gmask != 0x00FF00 ||
+		   dib.bmask != 0x0000FF)
+			goto lose;
+		dib.compression = 0;
+		if(dib.headerSize > 52 && dib.amask == 0xFF000000)
+			noalpha = false;
+	}
+
+	if(dib.compression != 0)
+		goto lose;
+
+	image = Image::create(dib.width, dib.height, dib.depth);
+	image->allocate();
+
+
+	if(image->palette){
+		int len = 1<<dib.depth;
+		uint8 (*color)[4] = (uint8 (*)[4])image->palette;
+		for(i = 0; i < len; i++){
+			color[i][2] = file.readU8();	// blue
+			color[i][1] = file.readU8();	// green
+			color[i][0] = file.readU8();	// red
+			color[i][3] = file.readU8();	// alpha
+			if(noalpha)
+				color[i][3] = 0xFF;
+		}
+	}
+
+	file.seek(bmp.offset, 0);
+
+	pad = image->width*image->bpp % 4;
+
+	uint8 *px, *line;
+	line = image->pixels + (image->height-1)*image->stride;
+	for(y = 0; y < image->height; y++){
+		px = line;
+		for(x = 0; x < image->width; x++){
+			switch(image->depth){
+			case 4:
+				i = file.readU8();;
+				px[x+0] = (i>>4)&0xF;
+				px[x+1] = i&0xF;
+				x++;
+				break;
+
+			case 8:
+				px[x] = file.readU8();
+				break;
+
+			case 16:
+				// TODO: what format is this even? and what does Image expect?
+				px[x*2 + 0] = file.readU8();
+				px[x*2 + 1] = file.readU8();
+				break;
+
+			case 24:
+				px[x*3 + 2] = file.readU8();
+				px[x*3 + 1] = file.readU8();
+				px[x*3 + 0] = file.readU8();
+				break;
+
+			case 32:
+				px[x*4 + 2] = file.readU8();
+				px[x*4 + 1] = file.readU8();
+				px[x*4 + 0] = file.readU8();
+				px[x*4 + 3] = file.readU8();
+				if(noalpha)
+					px[x*4 + 3] = 0xFF;
+				break;
+
+			default:
+				goto lose;
+			}
+		}
+
+		line -= image->stride;
+		file.seek(pad);
+	}
+
+	
+	file.close();
+	rwFree(data);
+	return image;
+
+lose:
+	file.close();
+	rwFree(data);
+	return nil;
+}
+
+/* can't write alpha */
+void
+writeBMP(Image *image, const char *filename)
+{
+	ASSERTLITTLE;
+	uint8 *p;
+	StreamFile file;
+	if(!file.open(filename, "wb")){
+		RWERROR((ERR_FILE, filename));
+		return;
+	}
+
+	int32 pallen = image->depth > 8  ? 0 :
+	               image->depth == 4 ? 16 : 256;
+	int32 stride = image->width*image->depth/8;
+	int32 depth = image->depth == 32 ? 24 : image->depth;
+	stride = stride+3 & ~3;
+
+	// File headers
+	BMPheader bmp;
+	bmp.magic = 0x4D42;	// BM
+	bmp.size = 0x36 + 4*pallen + image->height*stride;
+	bmp.reserved[0] = 0;
+	bmp.reserved[1] = 0;
+	bmp.offset = 0x36 + 4*pallen;
+	bmp.write(&file);
+
+	DIBheader dib;
+	dib.headerSize = 0x28;
+	dib.width = image->width;
+	dib.height = image->height;
+	dib.numPlanes = 1;
+	dib.depth = depth;
+	dib.compression = 0;
+	dib.imgSize = 0;
+	dib.hres = 2835;	// 72dpi
+	dib.vres = 2835;	// 72dpi
+	dib.paletteLen = 0;
+	dib.numImportant = 0;
+	file.write8(&dib, dib.headerSize);
+
+	for(int i = 0; i < pallen; i++){
+		file.writeU8(image->palette[i*4+2]);
+		file.writeU8(image->palette[i*4+1]);
+		file.writeU8(image->palette[i*4+0]);
+		file.writeU8(0xFF);
+	}
+
+	uint8 *line = image->pixels + (image->height-1)*image->stride;
+	int32 n;
+	for(int y = 0; y < image->height; y++){
+		p = line;
+		for(int x = 0; x < image->width; x++){
+			switch(image->depth){
+			case 4:
+				file.writeU8((p[0]&0xF)<<4 | (p[1]&0xF));
+				p += 2;
+				x++;
+				break;
+			case 8:
+				file.writeU8(*p++);
+				break;
+			case 16:
+				file.writeU8(p[0]);
+				file.writeU8(p[1]);
+				p += 2;
+				break;
+			case 24:
+				file.writeU8(p[2]);
+				file.writeU8(p[1]);
+				file.writeU8(p[0]);
+				p += 3;
+				break;
+			case 32:
+				file.writeU8(p[2]);
+				file.writeU8(p[1]);
+				file.writeU8(p[0]);
+				p += 4;
+			}
+		}
+		n = (p-line) % 4;
+		while(n--)
+			file.writeU8(0);
+		line -= image->stride;
+	}
+
+	file.close();
+}
+
+}