SDL_drawline.c
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/*
Simple DirectMedia Layer
Copyright (C) 1997-2019 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_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) {
return SDL_SetError("SDL_DrawLine(): Passed NULL destination surface");
}
func = SDL_CalculateDrawLineFunc(dst->format);
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_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) {
return SDL_SetError("SDL_DrawLines(): Passed NULL destination surface");
}
func = SDL_CalculateDrawLineFunc(dst->format);
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_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
continue;
}
/* Draw the end if it was clipped */
draw_end = (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_RENDER_DISABLED */
/* 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:340
points
GLfixed GLfixed GLint GLint GLfixed points
Definition: SDL_opengl_glext.h:4558
SDL_memset
#define SDL_memset
Definition: SDL_dynapi_overrides.h:386
ABS
#define ABS(_x)
Definition: SDL_draw.h:293
Uint32
uint32_t Uint32
Definition: SDL_stdinc.h:203
SDL_PixelFormat::BitsPerPixel
Uint8 BitsPerPixel
Definition: SDL_pixels.h:319
SDL_PixelFormat::BytesPerPixel
Uint8 BytesPerPixel
Definition: SDL_pixels.h:320
SDL_DrawPoint
int SDL_DrawPoint(SDL_Surface *dst, int x, int y, Uint32 color)
Definition: SDL_drawpoint.c:30
SDL_Surface
A collection of pixels used in software blitting.
Definition: SDL_surface.h:70
NULL
#define NULL
Definition: begin_code.h:167
SDL_PixelFormat::format
Uint32 format
Definition: SDL_pixels.h:317
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
SDL_PixelFormat::Rmask
Uint32 Rmask
Definition: SDL_pixels.h:322
x1
GLuint GLfloat GLfloat GLfloat x1
Definition: SDL_opengl_glext.h:8583
func
GLenum func
Definition: SDL_opengl_glext.h:657
length
GLuint GLsizei GLsizei * length
Definition: SDL_opengl_glext.h:669
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:1737
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:375
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:1148
VLINE
#define VLINE(type, op, draw_end)
Definition: SDL_draw.h:318
AALINE
#define AALINE(x1, y1, x2, y2, opaque_op, blend_op, draw_end)
Definition: SDL_draw.h:537
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
Uint16
uint16_t Uint16
Definition: SDL_stdinc.h:191
DRAW_SETPIXELXY_BLEND_ARGB8888
#define DRAW_SETPIXELXY_BLEND_ARGB8888(x, y)
Definition: SDL_draw.h:205
SDL_PixelFormat::Amask
Uint32 Amask
Definition: SDL_pixels.h:325
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:143
SDL_PixelFormat
Definition: SDL_pixels.h:315
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:239
y
GLint GLint GLint GLint GLint GLint y
Definition: SDL_opengl.h:1574
SDL_drawline.h
SDL_TRUE
@ SDL_TRUE
Definition: SDL_stdinc.h:164
SDL_Point
The structure that defines a point (integer)
Definition: SDL_rect.h:48
x2
GLfixed GLfixed x2
Definition: SDL_opengl_glext.h:4583
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:174
DRAW_SETPIXELXY4_BLEND_RGB
#define DRAW_SETPIXELXY4_BLEND_RGB(x, y)
Definition: SDL_draw.h:242
SDL_drawpoint.h
DRAW_SETPIXELXY_BLEND_RGB555
#define DRAW_SETPIXELXY_BLEND_RGB555(x, y)
Definition: SDL_draw.h:112
y1
GLfixed y1
Definition: SDL_opengl_glext.h:4583
DRAW_FASTSETPIXEL1
#define DRAW_FASTSETPIXEL1
Definition: SDL_draw.h:34
y2
GLfixed GLfixed GLfixed y2
Definition: SDL_opengl_glext.h:4583
HLINE
#define HLINE(type, op, draw_end)
Definition: SDL_draw.h:296
SDL_IntersectRectAndLine
#define SDL_IntersectRectAndLine
Definition: SDL_dynapi_overrides.h:297
void
const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char int const SDL_PRINTF_FORMAT_STRING char const char const SDL_SCANF_FORMAT_STRING 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
SDL_bool
SDL_bool
Definition: SDL_stdinc.h:161
Uint8
uint8_t Uint8
Definition: SDL_stdinc.h:179