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Add triangle size to pixelinfo

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This commit is contained in:
Miloslav Číž 2019-05-30 19:46:23 +02:00
parent d18807b077
commit 714f41f7ca
2 changed files with 20 additions and 18 deletions
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34
small3dlib.h
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@ -456,17 +456,16 @@ typedef struct
S3L_ScreenCoord x; ///< Screen X coordinate. S3L_ScreenCoord x; ///< Screen X coordinate.
S3L_ScreenCoord y; ///< Screen Y coordinate. S3L_ScreenCoord y; ///< Screen Y coordinate.
S3L_Unit barycentric0; /**< Barycentric coord 0 (corresponds to 1st vertex). S3L_Unit barycentric[3]; /**< Barycentric coords corresponds to the three
Together with 1 and 2 coords these serve to vertices. These serve to locate the pixel on a
locate the pixel on a triangle and interpolate triangle and interpolate values between it's
values between it's three points. The sum of the three points. The sum of the three coordinates
three coordinates will always be exactly will always be exactly S3L_FRACTIONS_PER_UNIT. */
S3L_FRACTIONS_PER_UNIT. */
S3L_Unit barycentric1; ///< Baryc. coord 1 (corresponds to 2nd vertex).
S3L_Unit barycentric2; ///< Baryc. coord 2 (corresponds to 3rd vertex).
S3L_Index triangleID; ///< Triangle index. S3L_Index triangleID; ///< Triangle index.
S3L_Index modelID; S3L_Index modelID;
S3L_Unit depth; ///< Depth (only if depth is turned on). S3L_Unit depth; ///< Depth (only if depth is turned on).
S3L_ScreenCoord triangleSize[2] /**< Rasterized triangle width and height,
can be used e.g. for MIP mapping. */
} S3L_PixelInfo; /**< Used to pass the info about a rasterized pixel } S3L_PixelInfo; /**< Used to pass the info about a rasterized pixel
(fragment) to the user-defined drawing func. */ (fragment) to the user-defined drawing func. */
@ -1030,9 +1029,9 @@ void S3L_initPixelInfo(S3L_PixelInfo *p) // TODO: maybe non-pointer for p
{ // could be faster? { // could be faster?
p->x = 0; p->x = 0;
p->y = 0; p->y = 0;
p->barycentric0 = S3L_FRACTIONS_PER_UNIT; p->barycentric[0] = S3L_FRACTIONS_PER_UNIT;
p->barycentric1 = 0; p->barycentric[1] = 0;
p->barycentric2 = 0; p->barycentric[2] = 0;
p->triangleID = 0; p->triangleID = 0;
p->depth = 0; p->depth = 0;
} }
@ -1322,7 +1321,7 @@ void S3L_drawTriangle(
tPointSx = x##t;\ tPointSx = x##t;\
tPointSy = y##t;\ tPointSy = y##t;\
tPointPP = &point##t;\ tPointPP = &point##t;\
barycentric2 = &(p.barycentric##t);\ barycentric2 = &(p.barycentric[t]);\
int16_t aDx = x##a - x##t;\ int16_t aDx = x##a - x##t;\
int16_t bDx = x##b - x##t;\ int16_t bDx = x##b - x##t;\
int16_t aDy = S3L_nonZero(y##a - y##t);\ int16_t aDy = S3L_nonZero(y##a - y##t);\
@ -1332,16 +1331,16 @@ void S3L_drawTriangle(
lPointSx = x##a; lPointSy = y##a;\ lPointSx = x##a; lPointSy = y##a;\
rPointSx = x##b; rPointSy = y##b;\ rPointSx = x##b; rPointSy = y##b;\
lPointPP = &point##a; rPointPP = &point##b;\ lPointPP = &point##a; rPointPP = &point##b;\
barycentric0 = &(p.barycentric##b);\ barycentric0 = &(p.barycentric[b]);\
barycentric1 = &(p.barycentric##a);\ barycentric1 = &(p.barycentric[a]);\
}\ }\
else\ else\
{\ {\
lPointSx = x##b; lPointSy = y##b;\ lPointSx = x##b; lPointSy = y##b;\
rPointSx = x##a; rPointSy = y##a;\ rPointSx = x##a; rPointSy = y##a;\
lPointPP = &point##b; rPointPP = &point##a;\ lPointPP = &point##b; rPointPP = &point##a;\
barycentric0 = &(p.barycentric##a);\ barycentric0 = &(p.barycentric[a]);\
barycentric1 = &(p.barycentric##b);\ barycentric1 = &(p.barycentric[b]);\
}\ }\
} }
@ -1362,6 +1361,9 @@ void S3L_drawTriangle(
#undef assignPoints #undef assignPoints
p.triangleSize[0] = rPointSx - lPointSx;
p.triangleSize[1] = (rPointSy > lPointSy ? rPointSy : lPointSy) - tPointSy;
// now draw the triangle line by line: // now draw the triangle line by line:
S3L_ScreenCoord splitY; // Y of the vertically middle point of the triangle S3L_ScreenCoord splitY; // Y of the vertically middle point of the triangle

4
testSDL.c
View file

@ -99,13 +99,13 @@ void drawPixel(S3L_PixelInfo *p)
0, 0,
0, 0,
15, 15,
p->barycentric0, p->barycentric1, p->barycentric2); p->barycentric[0], p->barycentric[1], p->barycentric[2]);
v = S3L_interpolateBarycentric( v = S3L_interpolateBarycentric(
0, 0,
15, 15,
0, 0,
p->barycentric0, p->barycentric1, p->barycentric2); p->barycentric[0], p->barycentric[1], p->barycentric[2]);
/* /*
u = S3L_interpolateBarycentric( u = S3L_interpolateBarycentric(
coords[0], coords[0],