From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 27 Dec 2025 12:03:39 -0800 Subject: Initial commit --- .../SDL-3.2.8/src/render/software/SDL_drawline.c | 199 +++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 contrib/SDL-3.2.8/src/render/software/SDL_drawline.c (limited to 'contrib/SDL-3.2.8/src/render/software/SDL_drawline.c') diff --git a/contrib/SDL-3.2.8/src/render/software/SDL_drawline.c b/contrib/SDL-3.2.8/src/render/software/SDL_drawline.c new file mode 100644 index 0000000..59ba268 --- /dev/null +++ b/contrib/SDL-3.2.8/src/render/software/SDL_drawline.c @@ -0,0 +1,199 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. +*/ +#include "SDL_internal.h" + +#ifdef SDL_VIDEO_RENDER_SW + +#include "SDL_draw.h" +#include "SDL_drawline.h" +#include "SDL_drawpoint.h" + +static void SDL_DrawLine1(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, + bool draw_end) +{ + if (y1 == y2) { + int length; + int pitch = (dst->pitch / dst->fmt->bytes_per_pixel); + Uint8 *pixel; + if (x1 <= x2) { + pixel = (Uint8 *)dst->pixels + y1 * pitch + x1; + length = draw_end ? (x2 - x1 + 1) : (x2 - x1); + } else { + pixel = (Uint8 *)dst->pixels + y1 * pitch + x2; + if (!draw_end) { + ++pixel; + } + length = draw_end ? (x1 - x2 + 1) : (x1 - x2); + } + SDL_memset(pixel, color, length); + } else if (x1 == x2) { + VLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end); + } else if (ABS(x1 - x2) == ABS(y1 - y2)) { + DLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end); + } else { + BLINE(x1, y1, x2, y2, DRAW_FASTSETPIXELXY1, draw_end); + } +} + +static void SDL_DrawLine2(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, + bool draw_end) +{ + if (y1 == y2) { + HLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); + } else if (x1 == x2) { + VLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); + } else if (ABS(x1 - x2) == ABS(y1 - y2)) { + DLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); + } else { + Uint8 _r, _g, _b, _a; + const SDL_PixelFormatDetails *fmt = dst->fmt; + SDL_GetRGBA(color, fmt, dst->palette, &_r, &_g, &_b, &_a); + if (fmt->Rmask == 0x7C00) { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB555, + draw_end); + } else if (fmt->Rmask == 0xF800) { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB565, + draw_end); + } else { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY2_BLEND_RGB, + draw_end); + } + } +} + +static void SDL_DrawLine4(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, + bool draw_end) +{ + if (y1 == y2) { + HLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); + } else if (x1 == x2) { + VLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); + } else if (ABS(x1 - x2) == ABS(y1 - y2)) { + DLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); + } else { + Uint8 _r, _g, _b, _a; + const SDL_PixelFormatDetails *fmt = dst->fmt; + SDL_GetRGBA(color, fmt, dst->palette, &_r, &_g, &_b, &_a); + if (fmt->Rmask == 0x00FF0000) { + if (!fmt->Amask) { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_XRGB8888, + draw_end); + } else { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_ARGB8888, + draw_end); + } + } else { + AALINE(x1, y1, x2, y2, + DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY4_BLEND_RGB, + draw_end); + } + } +} + +typedef void (*DrawLineFunc)(SDL_Surface *dst, + int x1, int y1, int x2, int y2, + Uint32 color, bool draw_end); + +static DrawLineFunc SDL_CalculateDrawLineFunc(const SDL_PixelFormatDetails *fmt) +{ + switch (fmt->bytes_per_pixel) { + case 1: + if (fmt->bits_per_pixel < 8) { + break; + } + return SDL_DrawLine1; + case 2: + return SDL_DrawLine2; + case 4: + return SDL_DrawLine4; + } + return NULL; +} + +bool SDL_DrawLine(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color) +{ + DrawLineFunc func; + + if (!SDL_SurfaceValid(dst)) { + return SDL_InvalidParamError("SDL_DrawLine(): dst"); + } + + func = SDL_CalculateDrawLineFunc(dst->fmt); + if (!func) { + return SDL_SetError("SDL_DrawLine(): Unsupported surface format"); + } + + // Perform clipping + // FIXME: We don't actually want to clip, as it may change line slope + if (!SDL_GetRectAndLineIntersection(&dst->clip_rect, &x1, &y1, &x2, &y2)) { + return true; + } + + func(dst, x1, y1, x2, y2, color, true); + return true; +} + +bool SDL_DrawLines(SDL_Surface *dst, const SDL_Point *points, int count, Uint32 color) +{ + int i; + int x1, y1; + int x2, y2; + bool draw_end; + DrawLineFunc func; + + if (!SDL_SurfaceValid(dst)) { + return SDL_InvalidParamError("SDL_DrawLines(): dst"); + } + + func = SDL_CalculateDrawLineFunc(dst->fmt); + if (!func) { + return SDL_SetError("SDL_DrawLines(): Unsupported surface format"); + } + + for (i = 1; i < count; ++i) { + x1 = points[i - 1].x; + y1 = points[i - 1].y; + x2 = points[i].x; + y2 = points[i].y; + + // Perform clipping + // FIXME: We don't actually want to clip, as it may change line slope + if (!SDL_GetRectAndLineIntersection(&dst->clip_rect, &x1, &y1, &x2, &y2)) { + continue; + } + + // Draw the end if the whole line is a single point or it was clipped + draw_end = ((x1 == x2) && (y1 == y2)) || (x2 != points[i].x || y2 != points[i].y); + + func(dst, x1, y1, x2, y2, color, draw_end); + } + if (points[0].x != points[count - 1].x || points[0].y != points[count - 1].y) { + SDL_DrawPoint(dst, points[count - 1].x, points[count - 1].y, color); + } + return true; +} + +#endif // SDL_VIDEO_RENDER_SW -- cgit v1.2.3