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Fix depth bug

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This commit is contained in:
Miloslav Číž 2019-06-14 04:52:52 +02:00
parent 0587870c0f
commit b6bc2e5818
3 changed files with 28 additions and 28 deletions
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4
programs/hqOffline.c
View file

@ -141,10 +141,6 @@ color[1] = S3L_clamp(127 + normal.y / 4,0,255);
color[2] = S3L_clamp(127 + normal.z / 4,0,255);
*/
color[0] = S3L_clamp(p->depth - 8000,0,255);
color[1] = color[0];
color[2] = color[1];
frameBuffer[index] = color[0];
frameBuffer[index + 1] = color[1];
frameBuffer[index + 2] = color[2];

46
small3dlib.h
View file

@ -1789,20 +1789,27 @@ void S3L_drawTriangle(
velues can be computed. See
http://www.lysator.liu.se/~mikaelk/doc/perspectivetexture/ */
#if S3L_PERSPECTIVE_CORRECTION == 1
#define Z_RECIP_NUMERATOR\
(S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT)
#elif S3L_PERSPECTIVE_CORRECTION == 2
#define Z_RECIP_NUMERATOR\
(S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT)
#endif
/* ^ This numerator is a number by which we divide values for the
reciprocals. For PC == 2 it has to be lower because linear interpolation
scaling would make it overflow -- this results in lower depth precision
in bigger distance for PC == 2. */
S3L_Unit
tPointRecipZ, lPointRecipZ, rPointRecipZ, /* Reciprocals of the depth of
each triangle point. */
lRecip0, lRecip1, rRecip0, rRecip1; /* Helper variables for swapping
the above after split. */
tPointRecipZ = (S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT)
/ S3L_nonZero(tPointSS->z);
lPointRecipZ = (S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT)
/ S3L_nonZero(lPointSS->z);
rPointRecipZ = (S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT)
/ S3L_nonZero(rPointSS->z);
tPointRecipZ = Z_RECIP_NUMERATOR / S3L_nonZero(tPointSS->z);
lPointRecipZ = Z_RECIP_NUMERATOR / S3L_nonZero(lPointSS->z);
rPointRecipZ = Z_RECIP_NUMERATOR / S3L_nonZero(rPointSS->z);
lRecip0 = tPointRecipZ;
lRecip1 = lPointRecipZ;
@ -1930,7 +1937,7 @@ void S3L_drawTriangle(
S3L_FastLerpState depthPC, b0PC, b1PC;
depthPC.valueScaled =
((S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT) /
(Z_RECIP_NUMERATOR /
S3L_nonZero(S3L_interpolate(lRecipZ,rRecipZ,i,rowLength)))
<< S3L_FAST_LERP_QUALITY;
@ -1938,13 +1945,13 @@ void S3L_drawTriangle(
(
S3L_interpolateFrom0(rOverZ,i,rowLength)
* depthPC.valueScaled
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
b1PC.valueScaled =
(
(lOverZ - S3L_interpolateFrom0(lOverZ,i,rowLength))
* depthPC.valueScaled
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
int8_t rowCount = S3L_PC_APPROX_LENGTH;
#endif
@ -1961,7 +1968,7 @@ void S3L_drawTriangle(
#if S3L_COMPUTE_DEPTH
#if S3L_PERSPECTIVE_CORRECTION == 1
p.depth = (S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT) /
p.depth = Z_RECIP_NUMERATOR /
S3L_nonZero(S3L_interpolate(lRecipZ,rRecipZ,i,rowLength));
#elif S3L_PERSPECTIVE_CORRECTION == 2
if (rowCount >= S3L_PC_APPROX_LENGTH)
@ -1984,7 +1991,7 @@ void S3L_drawTriangle(
S3L_Unit nextDepthScaled =
(
(S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT) /
Z_RECIP_NUMERATOR /
S3L_nonZero(rRecipZ)
) << S3L_FAST_LERP_QUALITY;
@ -1995,7 +2002,7 @@ void S3L_drawTriangle(
(
rOverZ
* nextDepthScaled
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
b0PC.stepScaled =
(nextValue - b0PC.valueScaled) / maxI;
@ -2007,7 +2014,7 @@ void S3L_drawTriangle(
{
S3L_Unit nextDepthScaled =
(
(S3L_FRACTIONS_PER_UNIT * S3L_FRACTIONS_PER_UNIT) /
Z_RECIP_NUMERATOR /
S3L_nonZero(S3L_interpolate(lRecipZ,rRecipZ,nextI,rowLength))
) << S3L_FAST_LERP_QUALITY;
@ -2018,7 +2025,7 @@ void S3L_drawTriangle(
(
S3L_interpolateFrom0(rOverZ,nextI,rowLength)
* nextDepthScaled
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
b0PC.stepScaled =
(nextValue - b0PC.valueScaled) / S3L_PC_APPROX_LENGTH;
@ -2027,7 +2034,7 @@ void S3L_drawTriangle(
(
(lOverZ - S3L_interpolateFrom0(lOverZ,nextI,rowLength))
* nextDepthScaled
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
b1PC.stepScaled =
(nextValue - b1PC.valueScaled) / S3L_PC_APPROX_LENGTH;
@ -2059,13 +2066,13 @@ void S3L_drawTriangle(
(
S3L_interpolateFrom0(rOverZ,i,rowLength)
* p.depth
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
*barycentric1 =
(
(lOverZ - S3L_interpolateFrom0(lOverZ,i,rowLength))
* p.depth
) / S3L_FRACTIONS_PER_UNIT;
) / (Z_RECIP_NUMERATOR / S3L_FRACTIONS_PER_UNIT);
#elif S3L_PERSPECTIVE_CORRECTION == 2
*barycentric0 = S3L_getFastLerpValue(b0PC);
*barycentric1 = S3L_getFastLerpValue(b1PC);
@ -2111,6 +2118,7 @@ void S3L_drawTriangle(
#undef initPC
#undef initSide
#undef stepSide
#undef Z_RECIP_NUMERATOR
}
void S3L_rotate2DPoint(S3L_Unit *x, S3L_Unit *y, S3L_Unit angle)

4
todo.txt
View file

@ -76,10 +76,6 @@ bugs:
- Any of them can exceed the range <0,511>
- b0 + b1 can be > 511, which causes b2 (= 511 - b0 - b1) to be negative!
- Depth artifacts with PC != 0, can be seen very well in the HQ offline demo.
This appear at bigger depths, which makes the reciprocal values more
imprecise.
repeated:
- valgrind (and similar) checks