# 8bpp_base.cpp

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    00001 /* $Id: 8bpp_base.cpp 15428 2009-02-09 02:57:15Z rubidium $ */
    00002
    00005 #include "../stdafx.h"
    00006 #include "../gfx_func.h"
    00007 #include "8bpp_base.hpp"
    00008
    00009 void Blitter_8bppBase::DrawColourMappingRect(void *dst, int width, int height, int pal)
    00010 {
    00011   const uint8 *ctab = GetNonSprite(pal, ST_RECOLOUR) + 1;
    00012
    00013   do {
    00014     for (int i = 0; i != width; i++) *((uint8 *)dst + i) = ctab[((uint8 *)dst)[i]];
    00015     dst = (uint8 *)dst + _screen.pitch;
    00016   } while (--height);
    00017 }
    00018
    00019 void *Blitter_8bppBase::MoveTo(const void *video, int x, int y)
    00020 {
    00021   return (uint8 *)video + x + y * _screen.pitch;
    00022 }
    00023
    00024 void Blitter_8bppBase::SetPixel(void *video, int x, int y, uint8 colour)
    00025 {
    00026   *((uint8 *)video + x + y * _screen.pitch) = colour;
    00027 }
    00028
    00029 void Blitter_8bppBase::SetPixelIfEmpty(void *video, int x, int y, uint8 colour)
    00030 {
    00031   uint8 *dst = (uint8 *)video + x + y * _screen.pitch;
    00032   if (*dst == 0) *dst = colour;
    00033 }
    00034
    00035 void Blitter_8bppBase::DrawRect(void *video, int width, int height, uint8 colour)
    00036 {
    00037   do {
    00038     memset(video, colour, width);
    00039     video = (uint8 *)video + _screen.pitch;
    00040   } while (--height);
    00041 }
    00042
    00043 void Blitter_8bppBase::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour)
    00044 {
    00045   int dy;
    00046   int dx;
    00047   int stepx;
    00048   int stepy;
    00049   int frac;
    00050
    00051   dy = (y2 - y) * 2;
    00052   if (dy < 0) {
    00053     dy = -dy;
    00054     stepy = -1;
    00055   } else {
    00056     stepy = 1;
    00057   }
    00058
    00059   dx = (x2 - x) * 2;
    00060   if (dx < 0) {
    00061     dx = -dx;
    00062     stepx = -1;
    00063   } else {
    00064     stepx = 1;
    00065   }
    00066
    00067   if (x >= 0 && y >= 0 && x < screen_width && y < screen_height) this->SetPixel(video, x, y, colour);
    00068   if (dx > dy) {
    00069     frac = dy - (dx / 2);
    00070     while (x != x2) {
    00071       if (frac >= 0) {
    00072         y += stepy;
    00073         frac -= dx;
    00074       }
    00075       x += stepx;
    00076       frac += dy;
    00077       if (x >= 0 && y >= 0 && x < screen_width && y < screen_height) this->SetPixel(video, x, y, colour);
    00078     }
    00079   } else {
    00080     frac = dx - (dy / 2);
    00081     while (y != y2) {
    00082       if (frac >= 0) {
    00083         x += stepx;
    00084         frac -= dy;
    00085       }
    00086       y += stepy;
    00087       frac += dx;
    00088       if (x >= 0 && y >= 0 && x < screen_width && y < screen_height) this->SetPixel(video, x, y, colour);
    00089     }
    00090   }
    00091 }
    00092
    00093 void Blitter_8bppBase::CopyFromBuffer(void *video, const void *src, int width, int height)
    00094 {
    00095   uint8 *dst = (uint8 *)video;
    00096   uint8 *usrc = (uint8 *)src;
    00097
    00098   for (; height > 0; height--) {
    00099     memcpy(dst, usrc, width * sizeof(uint8));
    00100     usrc += width;
    00101     dst += _screen.pitch;
    00102   }
    00103 }
    00104
    00105 void Blitter_8bppBase::CopyToBuffer(const void *video, void *dst, int width, int height)
    00106 {
    00107   uint8 *udst = (uint8 *)dst;
    00108   uint8 *src = (uint8 *)video;
    00109
    00110   for (; height > 0; height--) {
    00111     memcpy(udst, src, width * sizeof(uint8));
    00112     src += _screen.pitch;
    00113     udst += width;
    00114   }
    00115 }
    00116
    00117 void Blitter_8bppBase::CopyImageToBuffer(const void *video, void *dst, int width, int height, int dst_pitch)
    00118 {
    00119   uint8 *udst = (uint8 *)dst;
    00120   uint8 *src = (uint8 *)video;
    00121
    00122   for (; height > 0; height--) {
    00123     memcpy(udst, src, width * sizeof(uint8));
    00124     src += _screen.pitch;
    00125     udst += dst_pitch;
    00126   }
    00127 }
    00128
    00129 void Blitter_8bppBase::ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y)
    00130 {
    00131   const uint8 *src;
    00132   uint8 *dst;
    00133
    00134   if (scroll_y > 0) {
    00135     /*Calculate pointers */
    00136     dst = (uint8 *)video + left + (top + height - 1) * _screen.pitch;
    00137     src = dst - scroll_y * _screen.pitch;
    00138
    00139     /* Decrease height and increase top */
    00140     top += scroll_y;
    00141     height -= scroll_y;
    00142     assert(height > 0);
    00143
    00144     /* Adjust left & width */
    00145     if (scroll_x >= 0) {
    00146       dst += scroll_x;
    00147       left += scroll_x;
    00148       width -= scroll_x;
    00149     } else {
    00150       src -= scroll_x;
    00151       width += scroll_x;
    00152     }
    00153
    00154     for (int h = height; h > 0; h--) {
    00155       memcpy(dst, src, width * sizeof(uint8));
    00156       src -= _screen.pitch;
    00157       dst -= _screen.pitch;
    00158     }
    00159   } else {
    00160     /* Calculate pointers */
    00161     dst = (uint8 *)video + left + top * _screen.pitch;
    00162     src = dst - scroll_y * _screen.pitch;
    00163
    00164     /* Decrese height. (scroll_y is <=0). */
    00165     height += scroll_y;
    00166     assert(height > 0);
    00167
    00168     /* Adjust left & width */
    00169     if (scroll_x >= 0) {
    00170       dst += scroll_x;
    00171       left += scroll_x;
    00172       width -= scroll_x;
    00173     } else {
    00174       src -= scroll_x;
    00175       width += scroll_x;
    00176     }
    00177
    00178     /* the y-displacement may be 0 therefore we have to use memmove,
    00179      * because source and destination may overlap */
    00180     for (int h = height; h > 0; h--) {
    00181       memmove(dst, src, width * sizeof(uint8));
    00182       src += _screen.pitch;
    00183       dst += _screen.pitch;
    00184     }
    00185   }
    00186 }
    00187
    00188 int Blitter_8bppBase::BufferSize(int width, int height)
    00189 {
    00190   return width * height;
    00191 }
    00192
    00193 void Blitter_8bppBase::PaletteAnimate(uint start, uint count)
    00194 {
    00195   /* Video backend takes care of the palette animation */
    00196 }
    00197
    00198 Blitter::PaletteAnimation Blitter_8bppBase::UsePaletteAnimation()
    00199 {
    00200   return Blitter::PALETTE_ANIMATION_VIDEO_BACKEND;
    00201 }