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Fix redundancy

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This commit is contained in:
Miloslav Číž 2018-11-17 19:02:47 +01:00
parent 469368530b
commit 20ec0693a7
1 changed files with 23 additions and 10 deletions
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33
s3l.h
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@ -3,12 +3,22 @@
#include <stdint.h> #include <stdint.h>
typedef int16_t S3L_UNIT;
#define S3L_FRACTIONS_PER_UNIT 1024
typedef int16_t S3L_COORD; typedef int16_t S3L_COORD;
typedef struct typedef struct
{ {
int16_t x; S3L_COORD x; ///< Screen X coordinate.
int16_t y; S3L_COORD y; ///< Screen Y coordinate.
S3L_UNIT barycentricA; /**< Barycentric coord A. Together with B and C coords
these serve to locate the pixel on a triangle and
interpolate values between it's three points. The
sum of the three coordinates will always be
exactly S3L_FRACTIONS_PER_UNIT. */
S3L_UNIT barycentricB; ///< Baryc. coord B, same semantics as barycentricA.
S3L_UNIT barycentricC; ///< Baryc. coord C, same semantics as barycentricA.
} S3L_PixelInfo; } S3L_PixelInfo;
typedef struct typedef struct
@ -188,22 +198,20 @@ void S3L_drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2
lErrAdd, rErrAdd, // error value to add in each Bresenham cycle lErrAdd, rErrAdd, // error value to add in each Bresenham cycle
lErrSub, rErrSub; // error value to substract when moving in x direction lErrSub, rErrSub; // error value to substract when moving in x direction
int16_t helperDxAbs, helperDyAbs; int16_t helperDxAbs;
#define initSide(v,p1,p2)\ #define initSide(v,p1,p2)\
v##X = p1##PointX;\ v##X = p1##PointX;\
v##Dx = p2##PointX - p1##PointX;\ v##Dx = p2##PointX - p1##PointX;\
v##Dy = p2##PointY - p1##PointY;\ v##Dy = p2##PointY - p1##PointY;\
helperDxAbs = S3L_abs(v##Dx);\ helperDxAbs = S3L_abs(v##Dx);\
helperDyAbs = S3L_abs(v##Dy);\
v##Inc = v##Dx >= 0 ? 1 : -1;\ v##Inc = v##Dx >= 0 ? 1 : -1;\
v##Err = 2 * helperDxAbs - helperDyAbs;\ v##Err = 2 * helperDxAbs - v##Dy;\
v##ErrAdd = 2 * helperDxAbs;\ v##ErrAdd = 2 * helperDxAbs;\
v##ErrSub = 2 * (helperDyAbs != 0 ? helperDyAbs : 1);\ v##ErrSub = 2 * v##Dy;\
v##ErrSub = v##ErrSub != 0 ? v##ErrSub : 1; /* don't allow 0, could lead v##ErrSub = v##ErrSub != 0 ? v##ErrSub : 1; /* don't allow 0, could lead
to an infinite substracting to an infinite substracting
loop */ loop */
#define stepSide(s)\ #define stepSide(s)\
while (s##Err > 0)\ while (s##Err > 0)\
{\ {\
@ -217,6 +225,13 @@ void S3L_drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2
S3L_PixelInfo p; S3L_PixelInfo p;
p.barycentricA = 0;
p.barycentricB = 0;
p.barycentricC = 0;
//lBarStep = S3L_FRACTIONS_PER_UNIT
//rBarStep = S3L_FRACTIONS_PER_UNIT
while (currentY <= endY) while (currentY <= endY)
{ {
if (currentY == splitY) if (currentY == splitY)
@ -248,9 +263,7 @@ void S3L_drawTriangle(int16_t x0, int16_t y0, int16_t x1, int16_t y1, int16_t x2
} }
#undef initSide #undef initSide
#undef stepSide #undef stepSide
} }
#endif #endif