SDL  2.0
SDL_drawline.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
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 #if SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED
24 
25 #include "SDL_draw.h"
26 #include "SDL_drawline.h"
27 #include "SDL_drawpoint.h"
28 
29 
30 static void
31 SDL_DrawLine1(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,
32  SDL_bool draw_end)
33 {
34  if (y1 == y2) {
35  int length;
36  int pitch = (dst->pitch / dst->format->BytesPerPixel);
37  Uint8 *pixel;
38  if (x1 <= x2) {
39  pixel = (Uint8 *)dst->pixels + y1 * pitch + x1;
40  length = draw_end ? (x2-x1+1) : (x2-x1);
41  } else {
42  pixel = (Uint8 *)dst->pixels + y1 * pitch + x2;
43  if (!draw_end) {
44  ++pixel;
45  }
46  length = draw_end ? (x1-x2+1) : (x1-x2);
47  }
48  SDL_memset(pixel, color, length);
49  } else if (x1 == x2) {
50  VLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);
51  } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
52  DLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);
53  } else {
54  BLINE(x1, y1, x2, y2, DRAW_FASTSETPIXELXY1, draw_end);
55  }
56 }
57 
58 static void
59 SDL_DrawLine2(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,
60  SDL_bool draw_end)
61 {
62  if (y1 == y2) {
63  HLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
64  } else if (x1 == x2) {
65  VLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
66  } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
67  DLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
68  } else {
69  Uint8 _r, _g, _b, _a;
70  const SDL_PixelFormat * fmt = dst->format;
71  SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);
72  if (fmt->Rmask == 0x7C00) {
73  AALINE(x1, y1, x2, y2,
75  draw_end);
76  } else if (fmt->Rmask == 0xF800) {
77  AALINE(x1, y1, x2, y2,
79  draw_end);
80  } else {
81  AALINE(x1, y1, x2, y2,
83  draw_end);
84  }
85  }
86 }
87 
88 static void
89 SDL_DrawLine4(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color,
90  SDL_bool draw_end)
91 {
92  if (y1 == y2) {
93  HLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
94  } else if (x1 == x2) {
95  VLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
96  } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
97  DLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
98  } else {
99  Uint8 _r, _g, _b, _a;
100  const SDL_PixelFormat * fmt = dst->format;
101  SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);
102  if (fmt->Rmask == 0x00FF0000) {
103  if (!fmt->Amask) {
104  AALINE(x1, y1, x2, y2,
106  draw_end);
107  } else {
108  AALINE(x1, y1, x2, y2,
110  draw_end);
111  }
112  } else {
113  AALINE(x1, y1, x2, y2,
115  draw_end);
116  }
117  }
118 }
119 
121  int x1, int y1, int x2, int y2,
122  Uint32 color, SDL_bool draw_end);
123 
124 static DrawLineFunc
126 {
127  switch (fmt->BytesPerPixel) {
128  case 1:
129  if (fmt->BitsPerPixel < 8) {
130  break;
131  }
132  return SDL_DrawLine1;
133  case 2:
134  return SDL_DrawLine2;
135  case 4:
136  return SDL_DrawLine4;
137  }
138  return NULL;
139 }
140 
141 int
142 SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color)
143 {
145 
146  if (!dst) {
147  return SDL_SetError("SDL_DrawLine(): Passed NULL destination surface");
148  }
149 
151  if (!func) {
152  return SDL_SetError("SDL_DrawLine(): Unsupported surface format");
153  }
154 
155  /* Perform clipping */
156  /* FIXME: We don't actually want to clip, as it may change line slope */
157  if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
158  return 0;
159  }
160 
161  func(dst, x1, y1, x2, y2, color, SDL_TRUE);
162  return 0;
163 }
164 
165 int
167  Uint32 color)
168 {
169  int i;
170  int x1, y1;
171  int x2, y2;
172  SDL_bool draw_end;
174 
175  if (!dst) {
176  return SDL_SetError("SDL_DrawLines(): Passed NULL destination surface");
177  }
178 
180  if (!func) {
181  return SDL_SetError("SDL_DrawLines(): Unsupported surface format");
182  }
183 
184  for (i = 1; i < count; ++i) {
185  x1 = points[i-1].x;
186  y1 = points[i-1].y;
187  x2 = points[i].x;
188  y2 = points[i].y;
189 
190  /* Perform clipping */
191  /* FIXME: We don't actually want to clip, as it may change line slope */
192  if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
193  continue;
194  }
195 
196  /* Draw the end if it was clipped */
197  draw_end = (x2 != points[i].x || y2 != points[i].y);
198 
199  func(dst, x1, y1, x2, y2, color, draw_end);
200  }
201  if (points[0].x != points[count-1].x || points[0].y != points[count-1].y) {
203  }
204  return 0;
205 }
206 
207 #endif /* SDL_VIDEO_RENDER_SW && !SDL_RENDER_DISABLED */
208 
209 /* vi: set ts=4 sw=4 expandtab: */
DRAW_FASTSETPIXELXY1
#define DRAW_FASTSETPIXELXY1(x, y)
Definition: SDL_draw.h:42
DLINE
#define DLINE(type, op, draw_end)
Definition: SDL_draw.h:396
points
GLfixed GLfixed GLint GLint GLfixed points
Definition: SDL_opengl_glext.h:4561
Uint8
uint8_t Uint8
Definition: SDL_stdinc.h:179
SDL_memset
#define SDL_memset
Definition: SDL_dynapi_overrides.h:386
ABS
#define ABS(_x)
Definition: SDL_draw.h:349
SDL_PixelFormat::BitsPerPixel
Uint8 BitsPerPixel
Definition: SDL_pixels.h:322
SDL_PixelFormat::BytesPerPixel
Uint8 BytesPerPixel
Definition: SDL_pixels.h:323
SDL_DrawPoint
int SDL_DrawPoint(SDL_Surface *dst, int x, int y, Uint32 color)
Definition: SDL_drawpoint.c:30
Uint16
uint16_t Uint16
Definition: SDL_stdinc.h:191
SDL_Surface
A collection of pixels used in software blitting.
Definition: SDL_surface.h:71
if
set set set set set set set macro pixldst1 abits if abits op else op endif endm macro pixldst2 abits if abits op else op endif endm macro pixldst4 abits if abits op else op endif endm macro pixldst0 abits op endm macro pixldst3 mem_operand op endm macro pixldst30 mem_operand op endm macro pixldst abits if abits elseif abits elseif abits elseif abits elseif abits pixldst0 abits else pixldst0 abits pixldst0 abits pixldst0 abits pixldst0 abits endif elseif abits else pixldst0 abits pixldst0 abits endif elseif abits else error unsupported bpp *numpix else pixst endif endm macro pixld1_s mem_operand if asr adds SRC_WIDTH_FIXED bpl add asl mov asr adds SRC_WIDTH_FIXED bpl add asl mov asr adds SRC_WIDTH_FIXED bpl add asl mov asr adds SRC_WIDTH_FIXED bpl add asl elseif asr adds SRC_WIDTH_FIXED bpl add asl mov asr adds SRC_WIDTH_FIXED bpl add asl else error unsupported endif endm macro pixld2_s mem_operand if mov asr add asl add asl mov asr sub UNIT_X add asl mov asr add asl add asl mov asr add UNIT_X add asl else pixld1_s mem_operand pixld1_s mem_operand endif endm macro pixld0_s mem_operand if asr adds SRC_WIDTH_FIXED bpl add asl elseif asr adds SRC_WIDTH_FIXED bpl add asl endif endm macro pixld_s_internal mem_operand if mem_operand pixld2_s mem_operand pixdeinterleave basereg elseif mem_operand elseif mem_operand elseif mem_operand elseif mem_operand pixld0_s mem_operand else pixld0_s mem_operand pixld0_s mem_operand pixld0_s mem_operand pixld0_s mem_operand endif elseif mem_operand else pixld0_s mem_operand pixld0_s mem_operand endif elseif mem_operand else error unsupported mem_operand if bpp mem_operand endif endm macro vuzp8 reg2 vuzp d d &reg2 endm macro vzip8 reg2 vzip d d &reg2 endm macro pixdeinterleave basereg basereg basereg basereg basereg endif endm macro pixinterleave basereg basereg basereg basereg basereg endif endm macro PF boost_increment endif if endif PF tst PF addne PF subne PF cmp ORIG_W if endif if endif if endif PF subge ORIG_W PF subges if endif if endif if endif endif endm macro cache_preload_simple endif if dst_r_bpp pld[DST_R, #(PREFETCH_DISTANCE_SIMPLE *dst_r_bpp/8)] endif if mask_bpp pld if[MASK, #(PREFETCH_DISTANCE_SIMPLE *mask_bpp/8)] endif endif endm macro fetch_mask_pixblock pixld mask_basereg pixblock_size MASK endm macro ensure_destination_ptr_alignment process_pixblock_tail_head if beq irp skip1(dst_w_bpp<=(lowbit *8)) &&((lowbit *8)<(pixblock_size *dst_w_bpp)) .if lowbit< 16 tst DST_R
Definition: pixman-arm-neon-asm.h:469
NULL
#define NULL
Definition: begin_code.h:167
SDL_PixelFormat::format
Uint32 format
Definition: SDL_pixels.h:320
count
GLuint GLuint GLsizei count
Definition: SDL_opengl.h:1571
SDL_DrawLine1
static void SDL_DrawLine1(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
Definition: SDL_drawline.c:31
Uint32
uint32_t Uint32
Definition: SDL_stdinc.h:203
SDL_PixelFormat::Rmask
Uint32 Rmask
Definition: SDL_pixels.h:325
x1
GLuint GLfloat GLfloat GLfloat x1
Definition: SDL_opengl_glext.h:8586
func
GLenum func
Definition: SDL_opengl_glext.h:660
length
GLuint GLsizei GLsizei * length
Definition: SDL_opengl_glext.h:672
SDL_CalculateDrawLineFunc
static DrawLineFunc SDL_CalculateDrawLineFunc(const SDL_PixelFormat *fmt)
Definition: SDL_drawline.c:125
DRAW_FASTSETPIXEL4
#define DRAW_FASTSETPIXEL4
Definition: SDL_draw.h:36
DRAW_FASTSETPIXEL2
#define DRAW_FASTSETPIXEL2
Definition: SDL_draw.h:35
dst
GLenum GLenum dst
Definition: SDL_opengl_glext.h:1740
SDL_DrawLine4
static void SDL_DrawLine4(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
Definition: SDL_drawline.c:89
BLINE
#define BLINE(x1, y1, x2, y2, op, draw_end)
Definition: SDL_draw.h:431
DRAW_FASTSETPIXELXY2
#define DRAW_FASTSETPIXELXY2(x, y)
Definition: SDL_draw.h:43
x
GLint GLint GLint GLint GLint x
Definition: SDL_opengl.h:1574
color
GLuint color
Definition: SDL_opengl_glext.h:1151
VLINE
#define VLINE(type, op, draw_end)
Definition: SDL_draw.h:374
AALINE
#define AALINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end)
Definition: SDL_draw.h:593
SDL_draw.h
DrawLineFunc
void(* DrawLineFunc)(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
Definition: SDL_drawline.c:120
DRAW_FASTSETPIXELXY4
#define DRAW_FASTSETPIXELXY4(x, y)
Definition: SDL_draw.h:44
DRAW_SETPIXELXY_BLEND_ARGB8888
#define DRAW_SETPIXELXY_BLEND_ARGB8888(x, y)
Definition: SDL_draw.h:241
SDL_PixelFormat::Amask
Uint32 Amask
Definition: SDL_pixels.h:328
SDL_GetRGBA
#define SDL_GetRGBA
Definition: SDL_dynapi_overrides.h:289
DRAW_SETPIXELXY_BLEND_RGB565
#define DRAW_SETPIXELXY_BLEND_RGB565(x, y)
Definition: SDL_draw.h:165
SDL_TRUE
@ SDL_TRUE
Definition: SDL_stdinc.h:164
SDL_PixelFormat
Definition: SDL_pixels.h:319
SDL_DrawLines
int SDL_DrawLines(SDL_Surface *dst, const SDL_Point *points, int count, Uint32 color)
Definition: SDL_drawline.c:166
SDL_DrawLine2
static void SDL_DrawLine2(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
Definition: SDL_drawline.c:59
DRAW_SETPIXELXY2_BLEND_RGB
#define DRAW_SETPIXELXY2_BLEND_RGB(x, y)
Definition: SDL_draw.h:282
y
GLint GLint GLint GLint GLint GLint y
Definition: SDL_opengl.h:1574
SDL_drawline.h
SDL_Point
The structure that defines a point (integer)
Definition: SDL_rect.h:49
x2
GLfixed GLfixed x2
Definition: SDL_opengl_glext.h:4586
SDL_SetError
#define SDL_SetError
Definition: SDL_dynapi_overrides.h:30
DRAW_SETPIXELXY_BLEND_RGB888
#define DRAW_SETPIXELXY_BLEND_RGB888(x, y)
Definition: SDL_draw.h:203
DRAW_SETPIXELXY4_BLEND_RGB
#define DRAW_SETPIXELXY4_BLEND_RGB(x, y)
Definition: SDL_draw.h:285
SDL_drawpoint.h
DRAW_SETPIXELXY_BLEND_RGB555
#define DRAW_SETPIXELXY_BLEND_RGB555(x, y)
Definition: SDL_draw.h:127
y1
GLfixed y1
Definition: SDL_opengl_glext.h:4586
DRAW_FASTSETPIXEL1
#define DRAW_FASTSETPIXEL1
Definition: SDL_draw.h:34
y2
GLfixed GLfixed GLfixed y2
Definition: SDL_opengl_glext.h:4586
HLINE
#define HLINE(type, op, draw_end)
Definition: SDL_draw.h:352
SDL_IntersectRectAndLine
#define SDL_IntersectRectAndLine
Definition: SDL_dynapi_overrides.h:297
SDL_bool
SDL_bool
Definition: SDL_stdinc.h:162
void
SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char int SDL_PRINTF_FORMAT_STRING const char const char SDL_SCANF_FORMAT_STRING const char return SDL_ThreadFunction const char void return Uint32 return Uint32 void
Definition: SDL_dynapi_procs.h:89
SDL_DrawLine
int SDL_DrawLine(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color)
Definition: SDL_drawline.c:142
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:50