Mercurial > hg > dmlib
view src/dmdrawline.h @ 2208:90ec1ec89c56
Revamp the palette handling in lib64gfx somewhat, add helper functions to
lib64util for handling external palette file options and add support for
specifying one of the "internal" palettes or external (.act) palette file to
gfxconv and 64vw.
author | Matti Hamalainen <ccr@tnsp.org> |
---|---|
date | Fri, 14 Jun 2019 05:01:12 +0300 |
parents | e06abfde6c39 |
children |
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/* * DMLib * -- Simple Bresenham's style line drawing * Programmed and designed by Matti 'ccr' Hamalainen * (C) Copyright 2011-2015 Tecnic Software productions (TNSP) */ int DM_DRAWLINE_NAME (SDL_Surface *screen, DMFloat fx0, DMFloat fy0, DMFloat fx1, DMFloat fy1, const Uint32 col #ifdef DM_DRAWLINE_ARGS DM_DRAWLINE_ARGS #endif ) #ifdef DM_HEADER ; #else { int dx, dy, xstep, ystep; const int qpitch = screen->pitch / DM_DRAWLINE_DST_BYTES; (void) qpitch; (void) col; // Clipping if (dmClipLineCoordsFloat(screen, &fx0, &fy0, &fx1, &fy1) < 0) return -1; int x0 = fx0, y0 = fy0, x1 = fx1, y1 = fy1; // Compute initial deltas dx = (x1 - x0) * 2; dy = (y1 - y0) * 2; if (dx < 0) { dx = -dx; xstep = -1; } else xstep = 1; if (dy < 0) { dy = -dy; ystep = -1; } else ystep = 1; #ifndef DM_DRAWLINE_SPEC // Compute offsets y0 *= qpitch; y1 *= qpitch; ystep *= qpitch; #endif #ifdef DM_DRAWLINE_INIT DM_DRAWLINE_INIT #endif DM_DRAWLINE_DST_TYPE *pix = (DM_DRAWLINE_DST_TYPE *) screen->pixels; (void) pix; // Continue based on which delta is larger if (dx > dy) { int afrac = dy - (dx / 2.0); while (x0 != x1) { if (afrac >= 0) { y0 += ystep; afrac -= dx; } x0 += xstep; afrac += dy; DM_DRAWLINE_INNER } } else { int afrac = dx - (dy / 2.0); while (y0 != y1) { if (afrac >= 0) { x0 += xstep; afrac -= dy; } y0 += ystep; afrac += dx; DM_DRAWLINE_INNER } } return 0; } #endif #undef DM_DRAWLINE_NAME #undef DM_DRAWLINE_ARGS #undef DM_DRAWLINE_DST_BYTES #undef DM_DRAWLINE_DST_TYPE #undef DM_DRAWLINE_INIT #undef DM_DRAWLINE_INNER