This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_blendline.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2010 Sam Lantinga
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This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"
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#include "SDL_draw.h"
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static void
SDL_BlendLine_RGB2(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
}
inva = (a ^ 0xff);
if (y1 == y2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
HLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB, draw_end);
break;
case SDL_BLENDMODE_ADD:
HLINE(Uint16, DRAW_SETPIXEL_ADD_RGB, draw_end);
break;
default:
HLINE(Uint16, DRAW_SETPIXEL_RGB, draw_end);
break;
}
} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint16, DRAW_SETPIXEL_ADD_RGB, draw_end);
break;
default:
VLINE(Uint16, DRAW_SETPIXEL_RGB, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint16, DRAW_SETPIXEL_ADD_RGB, draw_end);
break;
default:
DLINE(Uint16, DRAW_SETPIXEL_RGB, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY2_BLEND_RGB, DRAW_SETPIXELXY2_BLEND_RGB,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY2_ADD_RGB, DRAW_SETPIXELXY2_ADD_RGB,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY2_RGB, DRAW_SETPIXELXY2_BLEND_RGB,
draw_end);
break;
}
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}
}
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static void
SDL_BlendLine_RGB555(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
}
inva = (a ^ 0xff);
if (y1 == y2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
HLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB555, draw_end);
break;
case SDL_BLENDMODE_ADD:
HLINE(Uint16, DRAW_SETPIXEL_ADD_RGB555, draw_end);
break;
default:
HLINE(Uint16, DRAW_SETPIXEL_RGB555, draw_end);
break;
}
} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB555, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint16, DRAW_SETPIXEL_ADD_RGB555, draw_end);
break;
default:
VLINE(Uint16, DRAW_SETPIXEL_RGB555, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB555, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint16, DRAW_SETPIXEL_ADD_RGB555, draw_end);
break;
default:
DLINE(Uint16, DRAW_SETPIXEL_RGB555, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_BLEND_RGB555, DRAW_SETPIXELXY_BLEND_RGB555,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_ADD_RGB555, DRAW_SETPIXELXY_ADD_RGB555,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_RGB555, DRAW_SETPIXELXY_BLEND_RGB555,
draw_end);
break;
}
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static void
SDL_BlendLine_RGB565(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
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inva = (a ^ 0xff);
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if (y1 == y2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
HLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB565, draw_end);
break;
case SDL_BLENDMODE_ADD:
HLINE(Uint16, DRAW_SETPIXEL_ADD_RGB565, draw_end);
break;
default:
HLINE(Uint16, DRAW_SETPIXEL_RGB565, draw_end);
break;
}
} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB565, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint16, DRAW_SETPIXEL_ADD_RGB565, draw_end);
break;
default:
VLINE(Uint16, DRAW_SETPIXEL_RGB565, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint16, DRAW_SETPIXEL_BLEND_RGB565, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint16, DRAW_SETPIXEL_ADD_RGB565, draw_end);
break;
default:
DLINE(Uint16, DRAW_SETPIXEL_RGB565, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_BLEND_RGB565, DRAW_SETPIXELXY_BLEND_RGB565,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_ADD_RGB565, DRAW_SETPIXELXY_ADD_RGB565,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_RGB565, DRAW_SETPIXELXY_BLEND_RGB565,
draw_end);
break;
}
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}
}
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static void
SDL_BlendLine_RGB4(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
}
inva = (a ^ 0xff);
if (y1 == y2) {
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switch (blendMode) {
case SDL_BLENDMODE_BLEND:
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HLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB, draw_end);
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break;
case SDL_BLENDMODE_ADD:
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HLINE(Uint32, DRAW_SETPIXEL_ADD_RGB, draw_end);
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break;
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default:
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HLINE(Uint32, DRAW_SETPIXEL_RGB, draw_end);
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break;
}
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} else if (x1 == x2) {
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switch (blendMode) {
case SDL_BLENDMODE_BLEND:
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VLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB, draw_end);
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break;
case SDL_BLENDMODE_ADD:
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VLINE(Uint32, DRAW_SETPIXEL_ADD_RGB, draw_end);
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break;
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default:
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VLINE(Uint32, DRAW_SETPIXEL_RGB, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint32, DRAW_SETPIXEL_ADD_RGB, draw_end);
break;
default:
DLINE(Uint32, DRAW_SETPIXEL_RGB, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_BLEND_RGB, DRAW_SETPIXELXY4_BLEND_RGB,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_ADD_RGB, DRAW_SETPIXELXY4_ADD_RGB,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_RGB, DRAW_SETPIXELXY4_BLEND_RGB,
draw_end);
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break;
}
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}
}
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static void
SDL_BlendLine_RGBA4(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
}
inva = (a ^ 0xff);
if (y1 == y2) {
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switch (blendMode) {
case SDL_BLENDMODE_BLEND:
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HLINE(Uint32, DRAW_SETPIXEL_BLEND_RGBA, draw_end);
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break;
case SDL_BLENDMODE_ADD:
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HLINE(Uint32, DRAW_SETPIXEL_ADD_RGBA, draw_end);
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break;
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default:
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HLINE(Uint32, DRAW_SETPIXEL_RGBA, draw_end);
break;
}
} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint32, DRAW_SETPIXEL_BLEND_RGBA, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint32, DRAW_SETPIXEL_ADD_RGBA, draw_end);
break;
default:
VLINE(Uint32, DRAW_SETPIXEL_RGBA, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint32, DRAW_SETPIXEL_BLEND_RGBA, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint32, DRAW_SETPIXEL_ADD_RGBA, draw_end);
break;
default:
DLINE(Uint32, DRAW_SETPIXEL_RGBA, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_BLEND_RGBA, DRAW_SETPIXELXY4_BLEND_RGBA,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_ADD_RGBA, DRAW_SETPIXELXY4_ADD_RGBA,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY4_RGBA, DRAW_SETPIXELXY4_BLEND_RGBA,
draw_end);
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break;
}
}
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static void
SDL_BlendLine_RGB888(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
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const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
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inva = (a ^ 0xff);
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if (y1 == y2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
HLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB888, draw_end);
break;
case SDL_BLENDMODE_ADD:
HLINE(Uint32, DRAW_SETPIXEL_ADD_RGB888, draw_end);
break;
default:
HLINE(Uint32, DRAW_SETPIXEL_RGB888, draw_end);
break;
}
} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB888, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint32, DRAW_SETPIXEL_ADD_RGB888, draw_end);
break;
default:
VLINE(Uint32, DRAW_SETPIXEL_RGB888, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint32, DRAW_SETPIXEL_BLEND_RGB888, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint32, DRAW_SETPIXEL_ADD_RGB888, draw_end);
break;
default:
DLINE(Uint32, DRAW_SETPIXEL_RGB888, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_BLEND_RGB888, DRAW_SETPIXELXY_BLEND_RGB888,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_ADD_RGB888, DRAW_SETPIXELXY_ADD_RGB888,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_RGB888, DRAW_SETPIXELXY_BLEND_RGB888,
draw_end);
break;
}
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}
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static void
SDL_BlendLine_ARGB8888(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 _r, Uint8 _g, Uint8 _b, Uint8 _a,
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SDL_bool draw_end)
{
const SDL_PixelFormat *fmt = dst->format;
unsigned r, g, b, a, inva;
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if (blendMode == SDL_BLENDMODE_BLEND || blendMode == SDL_BLENDMODE_ADD) {
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r = DRAW_MUL(_r, _a);
g = DRAW_MUL(_g, _a);
b = DRAW_MUL(_b, _a);
a = _a;
} else {
r = _r;
g = _g;
b = _b;
a = _a;
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inva = (a ^ 0xff);
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if (y1 == y2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
HLINE(Uint32, DRAW_SETPIXEL_BLEND_ARGB8888, draw_end);
break;
case SDL_BLENDMODE_ADD:
HLINE(Uint32, DRAW_SETPIXEL_ADD_ARGB8888, draw_end);
break;
default:
HLINE(Uint32, DRAW_SETPIXEL_ARGB8888, draw_end);
break;
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} else if (x1 == x2) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
VLINE(Uint32, DRAW_SETPIXEL_BLEND_ARGB8888, draw_end);
break;
case SDL_BLENDMODE_ADD:
VLINE(Uint32, DRAW_SETPIXEL_ADD_ARGB8888, draw_end);
break;
default:
VLINE(Uint32, DRAW_SETPIXEL_ARGB8888, draw_end);
break;
}
} else if (ABS(x1 - x2) == ABS(y1 - y2)) {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
DLINE(Uint32, DRAW_SETPIXEL_BLEND_ARGB8888, draw_end);
break;
case SDL_BLENDMODE_ADD:
DLINE(Uint32, DRAW_SETPIXEL_ADD_ARGB8888, draw_end);
break;
default:
DLINE(Uint32, DRAW_SETPIXEL_ARGB8888, draw_end);
break;
}
} else {
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_BLEND_ARGB8888, DRAW_SETPIXELXY_BLEND_ARGB8888,
draw_end);
break;
case SDL_BLENDMODE_ADD:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_ADD_ARGB8888, DRAW_SETPIXELXY_ADD_ARGB8888,
draw_end);
break;
default:
AALINE(x1, y1, x2, y2,
DRAW_SETPIXELXY_ARGB8888, DRAW_SETPIXELXY_BLEND_ARGB8888,
draw_end);
break;
}
}
}
typedef void (*BlendLineFunc) (SDL_Surface * dst,
int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode,
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Uint8 r, Uint8 g, Uint8 b, Uint8 a,
SDL_bool draw_end);
static BlendLineFunc
SDL_CalculateBlendLineFunc(const SDL_PixelFormat * fmt)
{
switch (fmt->BytesPerPixel) {
case 2:
if (fmt->Rmask == 0x7C00) {
return SDL_BlendLine_RGB555;
} else if (fmt->Rmask == 0xF800) {
return SDL_BlendLine_RGB565;
} else {
return SDL_BlendLine_RGB2;
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}
break;
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case 4:
if (fmt->Rmask == 0x00FF0000) {
if (fmt->Amask) {
return SDL_BlendLine_ARGB8888;
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} else {
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return SDL_BlendLine_RGB888;
}
} else {
if (fmt->Amask) {
return SDL_BlendLine_RGBA4;
} else {
return SDL_BlendLine_RGB4;
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}
}
}
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return NULL;
}
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int
SDL_BlendLine(SDL_Surface * dst, int x1, int y1, int x2, int y2,
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SDL_BlendMode blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
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{
BlendLineFunc func;
if (!dst) {
SDL_SetError("SDL_BlendLine(): Passed NULL destination surface");
return -1;
}
func = SDL_CalculateBlendLineFunc(dst->format);
if (!func) {
SDL_SetError("SDL_BlendLine(): Unsupported surface format");
return -1;
}
/* 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;
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func(dst, x1, y1, x2, y2, blendMode, r, g, b, a, SDL_TRUE);
return 0;
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int
SDL_BlendLines(SDL_Surface * dst, const SDL_Point * points, int count,
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SDL_BlendMode blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
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{
int i;
int x1, y1;
int x2, y2;
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SDL_bool draw_end;
BlendLineFunc func;
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if (!dst) {
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SDL_SetError("SDL_BlendLines(): Passed NULL destination surface");
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return -1;
}
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func = SDL_CalculateBlendLineFunc(dst->format);
if (!func) {
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SDL_SetError("SDL_BlendLines(): Unsupported surface format");
return -1;
}
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;
}
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/* Draw the end if it was clipped */
draw_end = (x2 != points[i].x || y2 != points[i].y);
func(dst, x1, y1, x2, y2, blendMode, r, g, b, a, draw_end);
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}
if (points[0].x != points[count-1].x || points[0].y != points[count-1].y) {
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SDL_BlendPoint(dst, points[count-1].x, points[count-1].y,
blendMode, r, g, b, a);
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/* vi: set ts=4 sw=4 expandtab: */