mostly reduced s_triangle.i

s_triangle.i (text/plain), 1.98 KB, created by SpanKY on 2012-01-14 10:18:46 UTC

static __inline__ int IS_INF_OR_NAN(float x)
{
	union {
		float f;
		int i;
	} tmp;
	tmp.f = x;
	return tmp.i;
}

static void simple_textured_triangle(float **v1)
{
	float **v0;
	float **v2;
	typedef struct {
		float dx;
		float dy;
		int fsx;
		int fx0;
		int lines;
	} EdgeT;
	EdgeT eMaj;
	EdgeT eTop;
	EdgeT eBot;
	float oneOverArea;
	float **vMin;
	float **vMid;
	float **vMax;
	int vMin_fx;
	int vMin_fy;
	int vMid_fx;
	int vMid_fy;
	int vMax_fx;
	int vMax_fy;
	if (v1[0][1] <= v2[0][1]) {
		vMin = v0;
		vMax = v1;
		vMin_fy = v0[0][1];
	}
	vMin_fx = vMin[0][0];
	vMid_fx =
	    vMid[4][0] ? ((vMid[4][0] * (float)2048) +
			  0.5F) : ((vMid[4][0] * (float)2048) - 0.5F);
	eMaj.dx = (vMax_fx - vMin_fx) * (1.0F / (float)2048);
	eMaj.dy = (vMax_fy - vMin_fy) * (1.0F / (float)2048);
	eTop.dx = (vMax_fx - vMid_fx) * (1.0F / (float)2048);
	eBot.dy = (vMid_fy - vMin_fy) * (1.0F / (float)2048);
	float area = eMaj.dx * eBot.dy - eBot.dx * eMaj.dy;
	if (IS_INF_OR_NAN(area))
		return;
	oneOverArea = 1.0F / area;
	eBot.fx0 = vMin_fx;
	int scan_from_left_to_right;
	float eMaj_ds = (vMax[4][0] - vMin[4][0]);
	float eBot_ds;
	float stepx = oneOverArea * (eMaj_ds * eBot.dy - eMaj.dy * eBot_ds);
	int step = (stepx >= 0.0F) ? stepx : (stepx * (float)2048) - 0.5F;
	int subTriangle;
	int fxRightEdge = 0;
	for (subTriangle = 0; subTriangle <= 1; subTriangle++) {
		EdgeT *eRight;
		int lines;
		if (subTriangle == 0) {
			if (scan_from_left_to_right) {
				eRight = &eBot;
				lines = eRight->lines;
			} else {
				eRight = &eMaj;
			}
		} else {
			if (scan_from_left_to_right) {
				eRight = &eTop;
			}
			fxRightEdge = eRight->fsx;
		}
		while (lines > 0) {
			int end;
			int x;
			int y;
			x = 0;
			if (fxRightEdge <= x)
				end = 0;
			else
				end = fxRightEdge - x;
			if (end > 0 && y >= 0) {
				int i;
				char *rgb;
				for (i = 0; i < end; i++) {
					int it;
					char *texture;
					rgb[i] = texture[it];
					it += step;
				}
				PutRowRGB(rgb);
			}
		}
	}
}

void *foo()
{
	return simple_textured_triangle;
}