diff --git a/s3l.h b/s3l.h index 991fe10..58d3ddf 100644 --- a/s3l.h +++ b/s3l.h @@ -121,12 +121,15 @@ typedef int32_t S3L_Unit; /**< Units of measurement in 3D space. There is it will overflow. Also other things may overflow, so rather don't do it. */ -#define S3L_LERP_QUALITY 3 /**< Quality (scaling) of SOME linear interpolations. - 0 will most likely be faster, but artifacts can - occur, while higher values can fix this -- in - theory all higher values will have the same - speed (it is a shift value), but it mustn't be - too high to prevent overflow (3 seems okay). */ +#ifndef S3L_LERP_QUALITY + #define S3L_LERP_QUALITY 8 /**< Quality (scaling) of SOME linear + interpolations. 0 will most likely be faster, + but artifacts can occur for bigger tris, + while higher values can fix this -- in theory + all higher values will have the same speed + (it is a shift value), but it mustn't be too + high to prevent overflow. */ +#endif #define S3L_nonzero(value) ((value) != 0 ? (value) : 1) /**< prevents division by zero */ @@ -852,26 +855,25 @@ void S3L_drawTriangle( // draw the horizontal line - S3L_Unit tMax = S3L_nonzero(rX - lX - 1); // prevent division by zero - S3L_Unit t1 = 0; - S3L_Unit t2 = tMax; + S3L_Unit rowLength = S3L_nonzero(rX - lX - 1); // prevent zero div + + S3L_Unit b0 = 0; + S3L_Unit b1 = lSideUnitPos; + + S3L_Unit b0Step = rSideUnitPos / rowLength; + S3L_Unit b1Step = lSideUnitPos / rowLength; for (S3L_ScreenCoord x = lX; x < rX; ++x) { - // TODO: try to do this with stepping and S3L_LERP_QUALITY - *barycentric0 = - S3L_interpolateFrom0(rSideUnitPos >> S3L_LERP_QUALITY,t1,tMax); - - *barycentric1 = - S3L_interpolateFrom0(lSideUnitPos >> S3L_LERP_QUALITY,t2,tMax); - + *barycentric0 = b0 >> S3L_LERP_QUALITY; + *barycentric1 = b1 >> S3L_LERP_QUALITY; *barycentric2 = S3L_FRACTIONS_PER_UNIT - *barycentric0 - *barycentric1; p.x = x; S3L_PIXEL_FUNCTION(&p); - ++t1; - --t2; + b0 += b0Step; + b1 -= b1Step; } lSideUnitPos += lSideUnitStep; diff --git a/testSDL.c b/testSDL.c index b33b4d6..d8c4e5d 100644 --- a/testSDL.c +++ b/testSDL.c @@ -76,12 +76,13 @@ void drawPixel(S3L_PixelInfo *p) uint8_t col = texturePixel(u,v); -// setPixel(p->x,p->y,col * 120,20,(2 - col) * 120); - + setPixel(p->x,p->y,col * 120,20,(2 - col) * 120); +/* setPixel(p->x,p->y, p->barycentric0 / ((float) S3L_FRACTIONS_PER_UNIT) * 255, p->barycentric1 / ((float) S3L_FRACTIONS_PER_UNIT) * 255, p->barycentric2 / ((float) S3L_FRACTIONS_PER_UNIT) * 255); +*/ } const int16_t test_coords[] =