tesuto0 made for understanding doslib fast rendering~

diff --git a/src/tesuto0.c b/src/tesuto0.c
index 3b19cc1dfd13c1ae43f5d0b4bea6de970496bcd3..cde5794e399e0a8836670884a3ef95c048515f78 100755 (executable)
--- a/src/tesuto0.c
+++ b/src/tesuto0.c
@@ -115,77 +115,77 @@ int main(int argc,char **argv) {
        }
        //while (getch() != 13);
 
-//     /* make distinctive pattern offscreen, render sprite, copy onscreen */
-//     {
-//             const unsigned int offscreen_ofs = (vga_state.vga_stride * vga_state.vga_height);
-//             unsigned int i,j,o,o2,x,y,rx,ry,w,h;
-//             unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
-//                                             // if the sprite's edge pixels are clear anyway, you can set this to 0.
-//             VGA_RAM_PTR omemptr;
-//             int xdir=1,ydir=1;
-//
-//             /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
-//             x = 0;
-//             y = 0;
-//
-//             /* do it */
-//             omemptr = vga_state.vga_graphics_ram; // save original mem ptr
-//             while (1) {
-//                     /* stop animating if the user hits ENTER */
-//                     if (kbhit()) {
-//                             if (getch() == 13) break;
-//                     }
-//
-//                     /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
-//                     if (x >= overdraw) rx = (x - overdraw) & (~3);
-//                     else rx = 0;
-//                     if (y >= overdraw) ry = (y - overdraw);
-//                     else ry = 0;
-//                     h = vrl_header->height + overdraw + y - ry;
-//                     w = (x + vrl_header->width + (overdraw*2) + 3/*round up*/ - rx) & (~3);
-//                     if ((rx+w) > vga_state.vga_width) w = vga_state.vga_width-rx;
-//                     if ((ry+h) > vga_state.vga_height) h = vga_state.vga_height-ry;
-//
-//                     /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
-//                     vga_state.vga_draw_stride_limit = (vga_state.vga_width + 3/*round up*/ - x) >> 2;
-//                     vga_state.vga_draw_stride = w >> 2;
-//                     vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
-//
-//                     /* first draw pattern corresponding to that part of the screen. this COULD be optimized, obviously, but it's designed for study.
-//                      * also note we don't have to use the same stride as the display! */
-//                     for (i=rx;i < (rx+w);i++) {
-//                             o = (i-rx) >> 2;
-//                             vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
-//                             for (j=ry;j < (ry+h);j++,o += vga_state.vga_draw_stride)
-//                                     vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
-//                     }
-//
-//                     /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
-//                     draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
-//
-//                     /* restore ptr */
-//                     vga_state.vga_graphics_ram = omemptr;
-//
-//                     /* block copy to visible RAM from offscreen */
-//                     vga_setup_wm1_block_copy();
-//                     o = offscreen_ofs; // source offscreen
-//                     o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
-//                     for (i=0;i < h;i++,o += vga_state.vga_draw_stride,o2 += vga_state.vga_stride) vga_wm1_mem_block_copy(o2,o,w >> 2);
-//                     /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
-//                     vga_restore_rm0wm0();
-//
-//                     /* restore stride */
-//                     vga_state.vga_draw_stride_limit = vga_state.vga_draw_stride = vga_state.vga_stride;
-//
-//                     /* step */
-//                     x += xdir;
-//                     y += ydir;
-//                     if (x >= (vga_state.vga_width - 1) || x == 0)
-//                             xdir = -xdir;
-//                     if (y >= (vga_state.vga_height - 1) || y == 0)
-//                             ydir = -ydir;
-//             }
-//     }
+       /* make distinctive pattern offscreen, render sprite, copy onscreen */
+       {
+               const unsigned int offscreen_ofs = (vga_state.vga_stride * vga_state.vga_height);
+               unsigned int i,j,o,o2,x,y,rx,ry,w,h;
+               unsigned int overdraw = 1;      // how many pixels to "overdraw" so that moving sprites with edge pixels don't leave streaks.
+                                               // if the sprite's edge pixels are clear anyway, you can set this to 0.
+               VGA_RAM_PTR omemptr;
+               int xdir=1,ydir=1;
+
+               /* starting coords. note: this technique is limited to x coordinates of multiple of 4 */
+               x = 0;
+               y = 0;
+
+               /* do it */
+               omemptr = vga_state.vga_graphics_ram; // save original mem ptr
+               //while (1) {
+                       /* stop animating if the user hits ENTER */
+               //      if (kbhit()) {
+               //              if (getch() == 13) break;
+               //      }
+
+                       /* render box bounds. y does not need modification, but x and width must be multiple of 4 */
+                       if (x >= overdraw) rx = (x - overdraw) & (~3);
+                       else rx = 0;
+                       if (y >= overdraw) ry = (y - overdraw);
+                       else ry = 0;
+                       h = vrl_header->height + overdraw + y - ry;
+                       w = (x + vrl_header->width + (overdraw*2) + 3/*round up*/ - rx) & (~3);
+                       if ((rx+w) > vga_state.vga_width) w = vga_state.vga_width-rx;
+                       if ((ry+h) > vga_state.vga_height) h = vga_state.vga_height-ry;
+
+                       /* replace VGA stride with our own and mem ptr. then sprite rendering at this stage is just (0,0) */
+                       vga_state.vga_draw_stride_limit = (vga_state.vga_width + 3/*round up*/ - x) >> 2;
+                       vga_state.vga_draw_stride = w >> 2;
+                       vga_state.vga_graphics_ram = omemptr + offscreen_ofs;
+
+                       /* first draw pattern corresponding to that part of the screen. this COULD be optimized, obviously, but it's designed for study.
+                        * also note we don't have to use the same stride as the display! */
+                       for (i=rx;i < (rx+w);i++) {
+                               o = (i-rx) >> 2;
+                               vga_write_sequencer(0x02/*map mask*/,1 << (i&3));
+                               for (j=ry;j < (ry+h);j++,o += vga_state.vga_draw_stride)
+                                       vga_state.vga_graphics_ram[o] = (i^j)&15; // VRL samples put all colors in first 15!
+                       }
+
+                       /* then the sprite. note modding ram ptr means we just draw to (x&3,0) */
+                       draw_vrl1_vgax_modex(x-rx,y-ry,vrl_header,vrl_lineoffs,buffer+sizeof(*vrl_header),bufsz-sizeof(*vrl_header));
+
+                       /* restore ptr */
+                       vga_state.vga_graphics_ram = omemptr;
+
+                       /* block copy to visible RAM from offscreen */
+                       vga_setup_wm1_block_copy();
+                       o = offscreen_ofs; // source offscreen
+                       o2 = (ry * vga_state.vga_stride) + (rx >> 2); // dest visible (original stride)
+                       for (i=0;i < h;i++,o += vga_state.vga_draw_stride,o2 += vga_state.vga_stride) vga_wm1_mem_block_copy(o2,o,w >> 2);
+                       /* must restore Write Mode 0/Read Mode 0 for this code to continue drawing normally */
+                       vga_restore_rm0wm0();
+
+                       /* restore stride */
+                       vga_state.vga_draw_stride_limit = vga_state.vga_draw_stride = vga_state.vga_stride;
+
+                       /* step */
+                       x += xdir;
+                       y += ydir;
+                       if (x >= (vga_state.vga_width - 1) || x == 0)
+                               xdir = -xdir;
+                       if (y >= (vga_state.vga_height - 1) || y == 0)
+                               ydir = -ydir;
+               //}
+       }
 
        /* make distinctive pattern offscreen, render sprite, copy onscreen.
         * this time, we render the distinctive pattern to another offscreen location and just copy.