diff options
Diffstat (limited to 'shell/scalers')
| -rw-r--r-- | shell/scalers/scaler.c | 138 | ||||
| -rw-r--r-- | shell/scalers/scaler.h | 11 |
2 files changed, 149 insertions, 0 deletions
diff --git a/shell/scalers/scaler.c b/shell/scalers/scaler.c new file mode 100644 index 0000000..8d85b8a --- /dev/null +++ b/shell/scalers/scaler.c @@ -0,0 +1,138 @@ +#include <stdio.h>
+#include <stdint.h>
+#include "scaler.h"
+
+#define AVERAGE(z, x) ((((z) & 0xF7DEF7DE) >> 1) + (((x) & 0xF7DEF7DE) >> 1))
+#define AVERAGEHI(AB) ((((AB) & 0xF7DE0000) >> 1) + (((AB) & 0xF7DE) << 15))
+#define AVERAGELO(CD) ((((CD) & 0xF7DE) >> 1) + (((CD) & 0xF7DE0000) >> 17))
+
+// Support math
+#define Half(A) (((A) >> 1) & 0x7BEF)
+#define Quarter(A) (((A) >> 2) & 0x39E7)
+// Error correction expressions to piece back the lower bits together
+#define RestHalf(A) ((A) & 0x0821)
+#define RestQuarter(A) ((A) & 0x1863)
+
+// Error correction expressions for quarters of pixels
+#define Corr1_3(A, B) Quarter(RestQuarter(A) + (RestHalf(B) << 1) + RestQuarter(B))
+#define Corr3_1(A, B) Quarter((RestHalf(A) << 1) + RestQuarter(A) + RestQuarter(B))
+
+// Error correction expressions for halves
+#define Corr1_1(A, B) ((A) & (B) & 0x0821)
+
+// Quarters
+#define Weight1_3(A, B) (Quarter(A) + Half(B) + Quarter(B) + Corr1_3(A, B))
+#define Weight3_1(A, B) (Half(A) + Quarter(A) + Quarter(B) + Corr3_1(A, B))
+
+// Halves
+#define Weight1_1(A, B) (Half(A) + Half(B) + Corr1_1(A, B))
+
+
+void upscale_256x240_to_320x240_bilinearish(uint32_t* restrict dst, uint32_t* restrict src, uint_fast16_t width, uint_fast16_t height)
+{
+ uint16_t* Src16 = (uint16_t*) src;
+ uint16_t* Dst16 = (uint16_t*) dst;
+ // There are 64 blocks of 4 pixels horizontally, and 239 of 1 vertically.
+ // Each block of 4x1 becomes 5x1.
+ uint32_t BlockX, BlockY;
+ uint16_t* BlockSrc;
+ uint16_t* BlockDst;
+ for (BlockY = 0; BlockY < height; BlockY++)
+ {
+ BlockSrc = Src16 + BlockY * width * 1;
+ BlockDst = Dst16 + BlockY * 320 * 1;
+ for (BlockX = 0; BlockX < 64; BlockX++)
+ {
+ /* Horizontally:
+ * Before(4):
+ * (a)(b)(c)(d)
+ * After(5):
+ * (a)(abbb)(bc)(cccd)(d)
+ */
+
+ // -- Row 1 --
+ uint16_t _1 = *(BlockSrc );
+ *(BlockDst ) = _1;
+ uint16_t _2 = *(BlockSrc + 1);
+ *(BlockDst + 1) = Weight1_3( _1, _2);
+ uint16_t _3 = *(BlockSrc + 2);
+ *(BlockDst + 2) = Weight1_1( _2, _3);
+ uint16_t _4 = *(BlockSrc + 3);
+ *(BlockDst + 3) = Weight3_1( _3, _4);
+ *(BlockDst + 4) = _4;
+
+ BlockSrc += 4;
+ BlockDst += 5;
+ }
+ }
+}
+
+void upscale_256xXXX_to_320x240(uint32_t* restrict dst, uint32_t* restrict src, uint_fast16_t width, uint_fast16_t height)
+{
+ uint32_t midh = 240 / 2;
+ uint32_t Eh = 0;
+ uint32_t source;
+ uint32_t dh = 0;
+ uint32_t y, x;
+
+ for (y = 0; y < 240; y++)
+ {
+ source = dh * width / 2;
+
+ for (x = 0; x < 320/10; x++)
+ {
+ register uint32_t ab, cd, ef, gh;
+
+ __builtin_prefetch(dst + 4, 1);
+ __builtin_prefetch(src + source + 4, 0);
+
+ ab = src[source] & 0xF7DEF7DE;
+ cd = src[source + 1] & 0xF7DEF7DE;
+ ef = src[source + 2] & 0xF7DEF7DE;
+ gh = src[source + 3] & 0xF7DEF7DE;
+
+ if(Eh >= midh) {
+ ab = AVERAGE(ab, src[source + width/2]) & 0xF7DEF7DE; // to prevent overflow
+ cd = AVERAGE(cd, src[source + width/2 + 1]) & 0xF7DEF7DE; // to prevent overflow
+ ef = AVERAGE(ef, src[source + width/2 + 2]) & 0xF7DEF7DE; // to prevent overflow
+ gh = AVERAGE(gh, src[source + width/2 + 3]) & 0xF7DEF7DE; // to prevent overflow
+ }
+
+ *dst++ = ab;
+ *dst++ = ((ab >> 17) + ((cd & 0xFFFF) >> 1)) + (cd << 16);
+ *dst++ = (cd >> 16) + (ef << 16);
+ *dst++ = (ef >> 16) + (((ef & 0xFFFF0000) >> 1) + ((gh & 0xFFFF) << 15));
+ *dst++ = gh;
+
+ source += 4;
+
+ }
+ Eh += height; if(Eh >= 240) { Eh -= 240; dh++; }
+ }
+}
+
+
+/* alekmaul's scaler taken from mame4all */
+void bitmap_scale(uint32_t startx, uint32_t starty, uint32_t viswidth, uint32_t visheight, uint32_t newwidth, uint32_t newheight,uint32_t pitchsrc,uint32_t pitchdest, uint16_t* restrict src, uint16_t* restrict dst)
+{
+ uint32_t W,H,ix,iy,x,y;
+ x=startx<<16;
+ y=starty<<16;
+ W=newwidth;
+ H=newheight;
+ ix=(viswidth<<16)/W;
+ iy=(visheight<<16)/H;
+
+ do
+ {
+ uint16_t* restrict buffer_mem=&src[(y>>16)*pitchsrc];
+ W=newwidth; x=startx<<16;
+ do
+ {
+ *dst++=buffer_mem[x>>16];
+ x+=ix;
+ } while (--W);
+ dst+=pitchdest;
+ y+=iy;
+ } while (--H);
+}
diff --git a/shell/scalers/scaler.h b/shell/scalers/scaler.h new file mode 100644 index 0000000..f220800 --- /dev/null +++ b/shell/scalers/scaler.h @@ -0,0 +1,11 @@ +#ifndef SCALER_H
+#define SCALER_H
+
+#include <stdint.h>
+
+/* Generic */
+extern void bitmap_scale(uint32_t startx, uint32_t starty, uint32_t viswidth, uint32_t visheight, uint32_t newwidth, uint32_t newheight,uint32_t pitchsrc,uint32_t pitchdest, uint16_t* restrict src, uint16_t* restrict dst);
+extern void upscale_256xXXX_to_320x240(uint32_t* restrict dst, uint32_t* restrict src, uint_fast16_t width, uint_fast16_t height);
+extern void upscale_256x240_to_320x240_bilinearish(uint32_t* restrict dst, uint32_t* restrict src, uint_fast16_t width, uint_fast16_t height);
+
+#endif
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