| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2023 Sam Lantinga <slouken@libsdl.org> |
| |
| 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" |
| |
| #if SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED |
| |
| #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, |
| SDL_bool draw_end) |
| { |
| if (y1 == y2) { |
| int length; |
| int pitch = (dst->pitch / dst->format->BytesPerPixel); |
| 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, |
| SDL_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_PixelFormat *fmt = dst->format; |
| SDL_GetRGBA(color, fmt, &_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, |
| SDL_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_PixelFormat *fmt = dst->format; |
| SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a); |
| if (fmt->Rmask == 0x00FF0000) { |
| if (!fmt->Amask) { |
| AALINE(x1, y1, x2, y2, |
| DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_RGB888, |
| 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, SDL_bool draw_end); |
| |
| static DrawLineFunc SDL_CalculateDrawLineFunc(const SDL_PixelFormat *fmt) |
| { |
| switch (fmt->BytesPerPixel) { |
| case 1: |
| if (fmt->BitsPerPixel < 8) { |
| break; |
| } |
| return SDL_DrawLine1; |
| case 2: |
| return SDL_DrawLine2; |
| case 4: |
| return SDL_DrawLine4; |
| } |
| return NULL; |
| } |
| |
| int SDL_DrawLine(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color) |
| { |
| DrawLineFunc func; |
| |
| if (dst == NULL) { |
| return SDL_InvalidParamError("SDL_DrawLine(): dst"); |
| } |
| |
| func = SDL_CalculateDrawLineFunc(dst->format); |
| if (func == NULL) { |
| 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_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) { |
| return 0; |
| } |
| |
| func(dst, x1, y1, x2, y2, color, SDL_TRUE); |
| return 0; |
| } |
| |
| int SDL_DrawLines(SDL_Surface *dst, const SDL_Point *points, int count, |
| Uint32 color) |
| { |
| int i; |
| int x1, y1; |
| int x2, y2; |
| SDL_bool draw_end; |
| DrawLineFunc func; |
| |
| if (dst == NULL) { |
| return SDL_InvalidParamError("SDL_DrawLines(): dst"); |
| } |
| |
| func = SDL_CalculateDrawLineFunc(dst->format); |
| if (func == NULL) { |
| 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_IntersectRectAndLine(&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 0; |
| } |
| |
| #endif /* SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
