X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=blobdiff_plain;f=src%2Frlebmap.h;fp=src%2Frlebmap.h;h=3f36b163009bf62b316e0c099d69fe5231dde26b;hp=0000000000000000000000000000000000000000;hb=280b3d2a948e965d7af7f017809c27a2b2ee2ce2;hpb=0d60e0e144c0faf5efb9551d1d23b7463ce8a4c0

diff --git a/src/rlebmap.h b/src/rlebmap.h
new file mode 100644
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--- /dev/null
+++ b/src/rlebmap.h
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+#ifndef __RLE_BITMAP_H__
+#define __RLE_BITMAP_H__
+
+/* Limit streak count per scanline so we can directly jump to specific scanline
+ */
+#define RLE_STREAKS_PER_SCANLINE 4
+
+/* Streaks will not exceed this many pixels. This allows us to optimize with a
+ * padded framebuffer. If a streak start position happens to lie within
+ * framebuffer, we will blit it without checking for out of bounds */
+#define RLE_MAX_STREAK_LENGTH 32
+
+/* Using the following type for storing start and for storing length in (start,
+ * length) pairs. */
+#define RLE_TYPE unsigned char
+
+/* For now, keep a static fill color. We can change this. Not that much about
+ * speed, but let's keep function definitions more compact. */
+#define RLE_FILL_COLOR 0
+
+/* Two entries of RLE_FILL_COLOR (16 bits) packed one after the other. */
+#define RLE_FILL_COLOR_32 ((RLE_FILL_COLOR << 16) | RLE_FILL_COLOR)
+
+/* For fixed-point arithmetic. Used for scaling. */
+#define RLE_FIXED_BITS 16
+
+/* This is a bitmap (image in 1bpp), encoded as streaks of consecutive pixels.
+ */
+typedef struct {
+	unsigned int w, h;
+
+	/* Each scan is RLE_BYTES_PER_SCANLINE long and contains pairs of
+	 * (start, length). */
+	RLE_TYPE *scans;
+} RleBitmap;
+
+/* Constructor */
+RleBitmap *rleCreate(unsigned int w, unsigned int h);
+
+/* Destructor */
+void rleDestroy(RleBitmap *rle);
+
+/* Clears 'rle' to "all transparent" */
+void rleClear(RleBitmap *rle);
+
+/* Encode 'pixels' into 'rle' and also return it. Pixels are either 0 or 1. This
+ * will create an RleBitmap of 'h' scanlines. */
+RleBitmap *rleEncode(RleBitmap *rle, unsigned char *pixels, unsigned int pixelsW,
+		     unsigned int pixelsH);
+
+/* Rearranges the streaks to make it less frequent that they produce garbege when interpolated */
+void rleDistributeStreaks(RleBitmap *rle);
+
+/* Blits without scaling */
+void rleBlit(RleBitmap *rle, unsigned short *dst, int dstW, int dstH, int dstStride, int blitX,
+	     int blitY);
+
+/* Scaled blit */
+void rleBlitScale(RleBitmap *rle, unsigned short *dst, int dstW, int dstH, int dstStride, int blitX,
+		  int blitY, float scaleX, float scaleY);
+
+/* Inverted blit (upside down) */
+void rleBlitScaleInv(RleBitmap *rle, unsigned short *dst, int dstW, int dstH, int dstStride,
+		     int blitX, int blitY, float scaleX, float scaleY);
+
+#endif // __RLE_BITMAP_H__