Atlas - SDL_drawline.c
Home / ext / SDL / src / render / software Lines: 1 | Size: 6582 bytes [Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)][FILE BEGIN]1/* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2026 Sam Lantinga <[email protected]> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20*/ 21#include "SDL_internal.h" 22 23#ifdef SDL_VIDEO_RENDER_SW 24 25#include "SDL_draw.h" 26#include "SDL_drawline.h" 27#include "SDL_drawpoint.h" 28 29static void SDL_DrawLine1(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, 30 bool draw_end) 31{ 32 if (y1 == y2) { 33 int length; 34 int pitch = (dst->pitch / dst->fmt->bytes_per_pixel); 35 Uint8 *pixels; 36 if (x1 <= x2) { 37 pixels = (Uint8 *)dst->pixels + y1 * pitch + x1; 38 length = draw_end ? (x2 - x1 + 1) : (x2 - x1); 39 } else { 40 pixels = (Uint8 *)dst->pixels + y1 * pitch + x2; 41 if (!draw_end) { 42 ++pixels; 43 } 44 length = draw_end ? (x1 - x2 + 1) : (x1 - x2); 45 } 46 SDL_memset(pixels, color, length); 47 } else if (x1 == x2) { 48 VLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end); 49 } else if (ABS(x1 - x2) == ABS(y1 - y2)) { 50 DLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end); 51 } else { 52 BLINE(x1, y1, x2, y2, DRAW_FASTSETPIXELXY1, draw_end); 53 } 54} 55 56static void SDL_DrawLine2(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, 57 bool draw_end) 58{ 59 if (y1 == y2) { 60 HLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); 61 } else if (x1 == x2) { 62 VLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); 63 } else if (ABS(x1 - x2) == ABS(y1 - y2)) { 64 DLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end); 65 } else { 66 Uint8 _r, _g, _b, _a; 67 const SDL_PixelFormatDetails *fmt = dst->fmt; 68 SDL_GetRGBA(color, fmt, dst->palette, &_r, &_g, &_b, &_a); 69 if (fmt->Rmask == 0x7C00) { 70 AALINE(x1, y1, x2, y2, 71 DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB555, 72 draw_end); 73 } else if (fmt->Rmask == 0xF800) { 74 AALINE(x1, y1, x2, y2, 75 DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB565, 76 draw_end); 77 } else { 78 AALINE(x1, y1, x2, y2, 79 DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY2_BLEND_RGB, 80 draw_end); 81 } 82 } 83} 84 85static void SDL_DrawLine4(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, 86 bool draw_end) 87{ 88 if (y1 == y2) { 89 HLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); 90 } else if (x1 == x2) { 91 VLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); 92 } else if (ABS(x1 - x2) == ABS(y1 - y2)) { 93 DLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end); 94 } else { 95 Uint8 _r, _g, _b, _a; 96 const SDL_PixelFormatDetails *fmt = dst->fmt; 97 SDL_GetRGBA(color, fmt, dst->palette, &_r, &_g, &_b, &_a); 98 if (fmt->Rmask == 0x00FF0000) { 99 if (!fmt->Amask) { 100 AALINE(x1, y1, x2, y2, 101 DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_XRGB8888, 102 draw_end); 103 } else { 104 AALINE(x1, y1, x2, y2, 105 DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_ARGB8888, 106 draw_end); 107 } 108 } else { 109 AALINE(x1, y1, x2, y2, 110 DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY4_BLEND_RGB, 111 draw_end); 112 } 113 } 114} 115 116typedef void (*DrawLineFunc)(SDL_Surface *dst, 117 int x1, int y1, int x2, int y2, 118 Uint32 color, bool draw_end); 119 120static DrawLineFunc SDL_CalculateDrawLineFunc(const SDL_PixelFormatDetails *fmt) 121{ 122 switch (fmt->bytes_per_pixel) { 123 case 1: 124 if (fmt->bits_per_pixel < 8) { 125 break; 126 } 127 return SDL_DrawLine1; 128 case 2: 129 return SDL_DrawLine2; 130 case 4: 131 return SDL_DrawLine4; 132 } 133 return NULL; 134} 135 136bool SDL_DrawLine(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color) 137{ 138 DrawLineFunc func; 139 140 CHECK_PARAM(!SDL_SurfaceValid(dst)) { 141 return SDL_InvalidParamError("SDL_DrawLine(): dst"); 142 } 143 144 func = SDL_CalculateDrawLineFunc(dst->fmt); 145 if (!func) { 146 return SDL_SetError("SDL_DrawLine(): Unsupported surface format"); 147 } 148 149 // Perform clipping 150 // FIXME: We don't actually want to clip, as it may change line slope 151 if (!SDL_GetRectAndLineIntersection(&dst->clip_rect, &x1, &y1, &x2, &y2)) { 152 return true; 153 } 154 155 func(dst, x1, y1, x2, y2, color, true); 156 return true; 157} 158 159bool SDL_DrawLines(SDL_Surface *dst, const SDL_Point *points, int count, Uint32 color) 160{ 161 int i; 162 int x1, y1; 163 int x2, y2; 164 bool draw_end; 165 DrawLineFunc func; 166 167 CHECK_PARAM(!SDL_SurfaceValid(dst)) { 168 return SDL_InvalidParamError("SDL_DrawLines(): dst"); 169 } 170 171 func = SDL_CalculateDrawLineFunc(dst->fmt); 172 if (!func) { 173 return SDL_SetError("SDL_DrawLines(): Unsupported surface format"); 174 } 175 176 for (i = 1; i < count; ++i) { 177 x1 = points[i - 1].x; 178 y1 = points[i - 1].y; 179 x2 = points[i].x; 180 y2 = points[i].y; 181 182 // Perform clipping 183 // FIXME: We don't actually want to clip, as it may change line slope 184 if (!SDL_GetRectAndLineIntersection(&dst->clip_rect, &x1, &y1, &x2, &y2)) { 185 continue; 186 } 187 188 // Draw the end if the whole line is a single point or it was clipped 189 draw_end = ((x1 == x2) && (y1 == y2)) || (x2 != points[i].x || y2 != points[i].y); 190 191 func(dst, x1, y1, x2, y2, color, draw_end); 192 } 193 if (points[0].x != points[count - 1].x || points[0].y != points[count - 1].y) { 194 SDL_DrawPoint(dst, points[count - 1].x, points[count - 1].y, color); 195 } 196 return true; 197} 198 199#endif // SDL_VIDEO_RENDER_SW 200[FILE END](C) 2025 0x4248 (C) 2025 4248 Media and 4248 Systems, All part of 0x4248 See LICENCE files for more information. 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