--- /dev/null
+/*
+ * upscale.c image upscaling
+ *
+ * This file contains upscalers for picodrive.
+ *
+ * scaler types:
+ * nn: nearest neighbour
+ * snn: "smoothed" nearest neighbour (see below)
+ * bln: bilinear (using only 0.25, 0.5, 0.75 as weight for better performance)
+ *
+ * "smoothed" nearest neighbour: uses the average of the source pixels if no
+ * source pixel covers more than 65% of the result pixel. It definitely
+ * looks better than nearest neighbour and is still quite fast. It creates
+ * a sharper look than a bilinear filter, at the price of some visible jags
+ * on diagonal edges.
+ * [NB this has been brought to my attn, which is probably very similar:
+ * https://www.drdobbs.com/image-scaling-with-bresenham/184405045?pgno=1]
+ *
+ * scaling modes:
+ * 256x___ -> 320x___ only horizontal scaling. Produces an aspect error of
+ * ~7% for NTSC 224 line modes, but is correct for PAL
+ * 256/320x224/240
+ * -> 320x240 always produces 320x240 at DAR 4:3
+ * 160x144 -> 320x240 game gear (currently unused)
+ *
+ * (C) 2021 kub <derkub@gmail.com>
+ */
+
+#include "upscale.h"
+
+/* 256x___ -> 320x___, H32/mode 4, PAR 5:4, for PAL DAR 4:3 (wrong for NTSC) */
+void upscale_clut_nn_256_320x___(u8 *__restrict di, int ds, u8 *__restrict si, int ss, int height)
+{
+ int y;
+
+ for (y = 0; y < height; y++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_nop);
+ }
+}
+
+void upscale_rgb_nn_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal)
+{
+ int y;
+
+ for (y = 0; y < height; y++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+}
+
+void upscale_rgb_snn_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal)
+{
+ int y;
+
+ for (y = 0; y < height; y++) {
+ h_upscale_snn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+}
+
+void upscale_rgb_bln_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal)
+{
+ int y;
+
+ for (y = 0; y < height; y++) {
+ h_upscale_bln_4_5(di, ds, si, ss, 256, f_pal);
+ }
+}
+
+/* 256x224 -> 320x240, H32/mode 4, PAR 5:4, for NTSC DAR 4:3 (wrong for PAL) */
+void upscale_clut_nn_256_320x224_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss)
+{
+ int y, j;
+
+ /* 14:15, 0 1 2 3 4 5 6 6 7 8 9 10 11 12 13 */
+ for (y = 0; y < 224; y += 14) {
+ /* lines 0-6 */
+ for (j = 0; j < 7; j++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_nop);
+ }
+ /* lines 8-14 */
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_nop);
+ }
+ /* line 7 */
+ di += 8*ds;
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 8*ds;
+ }
+}
+
+void upscale_rgb_nn_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 7; j++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_upscale_nn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+
+ di -= 8*ds;
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 8*ds;
+ }
+}
+
+void upscale_rgb_snn_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ /* 14:15, 0 1 2 3 4 5 5+6 6+7 7+8 8 9 10 11 12 13 */
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 7; j++) {
+ h_upscale_snn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_upscale_snn_4_5(di, ds, si, ss, 256, f_pal);
+ }
+
+ /* mix lines 6-8 */
+ di -= 8*ds;
+ v_mix(&di[0], &di[-ds], &di[ds], 320, p_05, f_nop);
+ v_mix(&di[-ds], &di[-2*ds], &di[-ds], 320, p_05, f_nop);
+ v_mix(&di[ ds], &di[ ds], &di[ 2*ds], 320, p_05, f_nop);
+ di += 8*ds;
+ }
+}
+
+void upscale_rgb_bln_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ /* 14:15, 0 1 2 2+3 3+4 4+5 5+6 6+7 7+8 8+9 9+10 10+11 11 12 13 */
+ for (y = 0; y < 224; y += 14) {
+ /* lines 0-2 */
+ for (j = 0; j < 3; j++) {
+ h_upscale_bln_4_5(di, ds, si, ss, 256, f_pal);
+ }
+ /* lines 3-14 mixing prep */
+ di += ds;
+ for (j = 0; j < 11; j++) {
+ h_upscale_bln_4_5(di, ds, si, ss, 256, f_pal);
+ }
+ di -= 12*ds;
+ /* mixing line 3: line 2 = -ds, line 3 = +ds */
+ v_mix(&di[0], &di[-ds], &di[ds], 320, p_025, f_nop);
+ di += ds;
+ /* mixing lines 4-5: line n = 0, line n+1 = +ds */
+ for (j = 0; j < 2; j++) {
+ v_mix(&di[0], &di[0], &di[ds], 320, p_025, f_nop);
+ di += ds;
+ }
+ /* mixing lines 6-8 */
+ for (j = 0; j < 3; j++) {
+ v_mix(&di[0], &di[0], &di[ds], 320, p_05, f_nop);
+ di += ds;
+ }
+ /* mixing lines 9-11 */
+ for (j = 0; j < 3; j++) {
+ v_mix(&di[0], &di[0], &di[ds], 320, p_075, f_nop);
+ di += ds;
+ }
+ /* lines 12-14, already in place */
+ di += 3*ds;
+ }
+}
+
+/* 320x224 -> 320x240, PAR 1:1, for NTSC, DAR 4:3 (wrong for PAL) */
+void upscale_clut_nn_320x224_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss)
+{
+ int y, j;
+
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_nop);
+ }
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_nop);
+ }
+
+ di += 8*ds;
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 8*ds;
+
+ }
+}
+
+void upscale_rgb_nn_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+
+ di -= 8*ds;
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 8*ds;
+ }
+}
+
+void upscale_rgb_snn_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+ di += ds;
+ for (j = 0; j < 7; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+
+ di -= 8*ds;
+ v_mix(&di[ 0], &di[-ds], &di[ds], 320, p_05, f_nop);
+ v_mix(&di[-ds], &di[-2*ds], &di[-ds], 320, p_05, f_nop);
+ v_mix(&di[ ds], &di[ ds], &di[ 2*ds], 320, p_05, f_nop);
+ di += 8*ds;
+ }
+}
+
+void upscale_rgb_bln_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 224; y += 14) {
+ for (j = 0; j < 3; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+ for (j = 0; j < 3; j++) {
+ v_mix(&di[0], &si[-ss], &si[0], 320, p_025, f_pal);
+ di += ds;
+ si += ss;
+ }
+ for (j = 0; j < 3; j++) {
+ v_mix(&di[0], &si[-ss], &si[0], 320, p_05, f_pal);
+ di += ds;
+ si += ss;
+ }
+ for (j = 0; j < 3; j++) {
+ v_mix(&di[0], &si[-ss], &si[0], 320, p_075, f_pal);
+ di += ds;
+ si += ss;
+ }
+ si -= ss;
+ for (j = 0; j < 3; j++) {
+ h_copy(di, ds, si, ss, 320, f_pal);
+ }
+ }
+}
+
+/* 160x144 -> 320x240: GG, PAR 6:5, scaling to 320x240 for DAR 4:3 */
+/* NB for smoother image could scale to 288x216, x*9/5, y*3/2 ?
+ * h: 11111 11112 22222 22233 33333 33444 44444 45555 55555
+ * 1 1 2 2+3 3 3+4 4 5 5
+ * v: 11 12 22
+ * 1 1+2 2
+ */
+void upscale_clut_nn_160_320x144_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss)
+{
+ int y, j;
+
+ /* 3:5, 0 0 1 1 2 */
+ for (y = 0; y < 144; y += 3) {
+ /* lines 0,2,4 */
+ for (j = 0; j < 3; j++) {
+ h_upscale_nn_1_2(di, ds, si, ss, 160, f_nop);
+ di += ds;
+ }
+ /* lines 1,3 */
+ di -= 5*ds;
+ for (j = 0; j < 2; j++) {
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 2*ds;
+ }
+ }
+}
+
+void upscale_rgb_nn_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 144; y += 3) {
+ for (j = 0; j < 3; j++) {
+ h_upscale_nn_1_2(di, ds, si, ss, 160, f_pal);
+ di += ds;
+ }
+ di -= 5*ds;
+ for (j = 0; j < 2; j++) {
+ v_copy(&di[0], &di[-ds], 320, f_nop);
+ di += 2*ds;
+ }
+ }
+}
+
+void upscale_rgb_snn_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ /* 3:5, 0 0+1 1 1+2 2 */
+ for (y = 0; y < 144; y += 3) {
+ for (j = 0; j < 3; j++) {
+ h_upscale_nn_1_2(di, ds, si, ss, 160, f_pal);
+ di += ds;
+ }
+ di -= 5*ds;
+ for (j = 0; j < 2; j++) {
+ v_mix(&di[0], &di[-ds], &di[ds], 320, p_05, f_nop);
+ di += 2*ds;
+ }
+ }
+}
+
+void upscale_rgb_bln_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal)
+{
+ int y, j;
+
+ for (y = 0; y < 144; y += 3) {
+ for (j = 0; j < 3; j++) {
+ h_upscale_nn_1_2(di, ds, si, ss, 160, f_pal);
+ di += ds;
+ }
+ di -= 5*ds;
+ v_mix(&di[0], &di[-ds], &di[ds], 320, p_075, f_nop);
+ di += 2*ds;
+ v_mix(&di[0], &di[-ds], &di[ds], 320, p_025, f_nop);
+ di += 2*ds;
+ }
+}
+
--- /dev/null
+/*
+ * upscale.h image upscaling
+ *
+ * This file contains upscalers for picodrive.
+ *
+ * scaler types:
+ * nn: nearest neighbour
+ * snn: "smoothed" nearest neighbour (see below)
+ * bln: bilinear (using only 0.25, 0.5, 0.75 as weight for better performance)
+ *
+ * "smoothed" nearest neighbour: uses the average of the source pixels if no
+ * source pixel covers more than 65% of the result pixel. It definitely
+ * looks better than nearest neighbour and is still quite fast. It creates
+ * a sharper look than a bilinear filter, at the price of some visible jags
+ * on diagonal edges.
+ * [NB this has been brought to my attn, which is probably very similar:
+ * https://www.drdobbs.com/image-scaling-with-bresenham/184405045?pgno=1]
+ *
+ * scaling modes:
+ * 256x___ -> 320x___ only horizontal scaling. Produces an aspect error of
+ * ~7% for NTSC 224 line modes, but is correct for PAL
+ * 256/320x224/240
+ * -> 320x240 always produces 320x240 at DAR 4:3
+ * 160x144 -> 320x240 game gear (currently unused)
+ *
+ * (C) 2021 kub <derkub@gmail.com>
+ */
+#include <pico/pico_types.h>
+
+/* RGB565 pixel mixing, see https://www.compuphase.com/graphic/scale3.htm and
+ http://blargg.8bitalley.com/info/rgb_mixing.html */
+//#define p_05(p1,p2) (t=((p1)&(p2)) + ((((p1)^(p2))&~0x0821)>>1))
+#define p_05(p1,p2) (t=((p1)+(p2) + ( ((p1)^(p2))&0x0821))>>1) // round up
+//#define p_05(p1,p2) (t=((p1)+(p2) - ( ((p1)^(p2))&0x0821))>>1) // round down
+#define p_025(p1,p2) (t=((p1)+(p2) + ( ((p1)^(p2))&0x0821))>>1, \
+ (( t)+(p2) + ( (( t)^(p2))&0x0821))>>1)
+#define p_075(p1,p2) p_025(p2,p1)
+
+/* pixel transforms, result must be RGB565 */
+#define f_pal(v) pal[v] // convert CLUT index -> RGB565
+#define f_nop(v) (v) // source already in RGB565
+
+/*
+scalers h:
+256->320: - (4:5) (256x224/240 -> 320x224/240)
+160->320: - (1:2) 2x (160x144 -> 320x240, GG)
+*/
+
+/* scale 4:5 */
+#define h_upscale_nn_4_5(di,ds,si,ss,w,f) do { \
+ /* 1111 1222 2233 3334 4444 */ \
+ /* 1 2 2 3 4 */ \
+ int i; \
+ for (i = 0; i < w; i += 4, si += 4, di += 5) { \
+ di[0] = f(si[0]); \
+ di[1] = f(si[1]); \
+ di[2] = f(si[1]); \
+ di[3] = f(si[2]); \
+ di[4] = f(si[3]); \
+ } \
+ di += ds - w/4*5; \
+ si += ss - w; \
+} while (0)
+
+#define h_upscale_snn_4_5(di,ds,si,ss,w,f) do { \
+ /* 1111 1222 2233 3334 4444 */ \
+ /* 1 2 2+3 3 4 */ \
+ int i, t; \
+ for (i = 0; i < w; i += 4, si += 4, di += 5) { \
+ di[0] = f(si[0]); \
+ di[1] = f(si[1]); \
+ di[2] = p_05(f(si[1]),f(si[2])); \
+ di[3] = f(si[2]); \
+ di[4] = f(si[3]); \
+ } \
+ di += ds - w/4*5; \
+ si += ss - w; \
+} while (0)
+
+#define h_upscale_bln_4_5(di,ds,si,ss,w,f) do { \
+ /* 1111 1222 2233 3334 4444 */ \
+ /* 1 2+3 2+3 3+4 4 */ \
+ int i, t; \
+ for (i = 0; i < w; i += 4, si += 4, di += 5) { \
+ di[0] = f(si[0]); \
+ di[1] = p_025(f(si[0]),f(si[1])); \
+ di[2] = p_05 (f(si[1]),f(si[2])); \
+ di[3] = p_075(f(si[2]),f(si[3])); \
+ di[4] = f(si[3]); \
+ } \
+ di += ds - w/4*5; \
+ si += ss - w; \
+} while (0)
+
+/* scale 1:2 integer scale */
+#define h_upscale_nn_1_2(di,ds,si,ss,w,f) do { \
+ int i; \
+ for (i = 0; i < w; i += 2, si += 2, di += 4) { \
+ di[0] = f(si[0]); \
+ di[1] = f(si[0]); \
+ di[2] = f(si[1]); \
+ di[3] = f(si[1]); \
+ } \
+ di += ds - w*2; \
+ si += ss - w; \
+} while (0)
+
+/* scale 1:1, copy */
+#define h_copy(di,ds,si,ss,w,f) do { \
+ int i; \
+ for (i = 0; i < w; i += 4, si += 4, di += 4) { \
+ di[0] = f(si[0]); \
+ di[1] = f(si[1]); \
+ di[2] = f(si[2]); \
+ di[3] = f(si[3]); \
+ } \
+ di += ds - w; \
+ si += ss - w; \
+} while (0)
+
+/*
+scalers v:
+224->240: - (14:15) (256/320x224 -> 320x240)
+144->240: - (3:5) (160x144 -> 320x240, GG)
+*/
+
+#define v_mix(di,li,ri,w,p_mix,f) do { \
+ int i, t; \
+ for (i = 0; i < w; i += 4) { \
+ (di)[i ] = p_mix(f((li)[i ]), f((ri)[i ])); \
+ (di)[i+1] = p_mix(f((li)[i+1]), f((ri)[i+1])); \
+ (di)[i+2] = p_mix(f((li)[i+2]), f((ri)[i+2])); \
+ (di)[i+3] = p_mix(f((li)[i+3]), f((ri)[i+3])); \
+ } \
+} while (0)
+
+#define v_copy(di,ri,w,f) do { \
+ int i; \
+ for (i = 0; i < w; i += 4) { \
+ (di)[i ] = f((ri)[i ]); \
+ (di)[i+1] = f((ri)[i+1]); \
+ (di)[i+2] = f((ri)[i+2]); \
+ (di)[i+3] = f((ri)[i+3]); \
+ } \
+} while (0)
+
+
+
+/* 256x___ -> 320x___, H32/mode 4, PAR 5:4, for PAL DAR 4:3 (wrong for NTSC) */
+void upscale_clut_nn_256_320x___(u8 *__restrict di, int ds, u8 *__restrict si, int ss, int height);
+void upscale_rgb_nn_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal);
+void upscale_rgb_snn_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal);
+void upscale_rgb_bln_256_320x___(u16 *__restrict di, int ds, u8 *__restrict si, int ss, int height, u16 *pal);
+
+/* 256x224 -> 320x240, H32/mode 4, PAR 5:4, for NTSC DAR 4:3 (wrong for PAL) */
+void upscale_clut_nn_256_320x224_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss);
+void upscale_rgb_nn_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_snn_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_bln_256_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+
+/* 320x224 -> 320x240, PAR 1:1, for NTSC, DAR 4:3 (wrong for PAL) */
+void upscale_clut_nn_320x224_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss);
+void upscale_rgb_nn_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_snn_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_bln_320x224_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+
+/* 160x144 -> 320x240: GG, PAR 6:5, scaling to 320x240 for DAR 4:3 */
+void upscale_clut_nn_160_320x144_240(u8 *__restrict di, int ds, u8 *__restrict si, int ss);
+void upscale_rgb_nn_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_snn_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
+void upscale_rgb_bln_160_320x144_240(u16 *__restrict di, int ds, u8 *__restrict si, int ss, u16 *pal);
notaz.gp2x.de / picodrive.git / commitdiff