X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=bootcensus;a=blobdiff_plain;f=src%2Fcensus%2Fgfxutil.c;fp=src%2Fcensus%2Fgfxutil.c;h=647920568dfc969677c6ce1e64939865845df82a;hp=0000000000000000000000000000000000000000;hb=10843571c724084c68d33d0438167d400cc8de2e;hpb=f9194c22d8073b69b3e64fc26b9e245b6b54d009

diff --git a/src/census/gfxutil.c b/src/census/gfxutil.c
new file mode 100644
index 0000000..6479205
--- /dev/null
+++ b/src/census/gfxutil.c
@@ -0,0 +1,217 @@
+#include "gfxutil.h"
+#include "census.h"
+
+enum {
+	IN		= 0,
+	LEFT	= 1,
+	RIGHT	= 2,
+	TOP		= 4,
+	BOTTOM	= 8
+};
+
+static int outcode(int x, int y, int xmin, int ymin, int xmax, int ymax)
+{
+	int code = 0;
+
+	if(x < xmin) {
+		code |= LEFT;
+	} else if(x > xmax) {
+		code |= RIGHT;
+	}
+	if(y < ymin) {
+		code |= TOP;
+	} else if(y > ymax) {
+		code |= BOTTOM;
+	}
+	return code;
+}
+
+#define FIXMUL(a, b)	(((a) * (b)) >> 8)
+#define FIXDIV(a, b)	(((a) << 8) / (b))
+
+#define LERP(a, b, t)	((a) + FIXMUL((b) - (a), (t)))
+
+int clip_line(int *x0, int *y0, int *x1, int *y1, int xmin, int ymin, int xmax, int ymax)
+{
+	int oc_out;
+
+	int oc0 = outcode(*x0, *y0, xmin, ymin, xmax, ymax);
+	int oc1 = outcode(*x1, *y1, xmin, ymin, xmax, ymax);
+
+	long fx0, fy0, fx1, fy1, fxmin, fymin, fxmax, fymax;
+
+	if(!(oc0 | oc1)) return 1;	/* both points are inside */
+
+	fx0 = *x0 << 8;
+	fy0 = *y0 << 8;
+	fx1 = *x1 << 8;
+	fy1 = *y1 << 8;
+	fxmin = xmin << 8;
+	fymin = ymin << 8;
+	fxmax = xmax << 8;
+	fymax = ymax << 8;
+
+	for(;;) {
+		long x, y, t;
+
+		if(oc0 & oc1) return 0;		/* both have points with the same outbit, not visible */
+		if(!(oc0 | oc1)) break;		/* both points are inside */
+
+		oc_out = oc0 ? oc0 : oc1;
+
+		if(oc_out & TOP) {
+			t = FIXDIV(fymin - fy0, fy1 - fy0);
+			x = LERP(fx0, fx1, t);
+			y = fymin;
+		} else if(oc_out & BOTTOM) {
+			t = FIXDIV(fymax - fy0, fy1 - fy0);
+			x = LERP(fx0, fx1, t);
+			y = fymax;
+		} else if(oc_out & LEFT) {
+			t = FIXDIV(fxmin - fx0, fx1 - fx0);
+			x = fxmin;
+			y = LERP(fy0, fy1, t);
+		} else if(oc_out & RIGHT) {
+			t = FIXDIV(fxmax - fx0, fx1 - fx0);
+			x = fxmax;
+			y = LERP(fy0, fy1, t);
+		}
+
+		if(oc_out == oc0) {
+			fx0 = x;
+			fy0 = y;
+			oc0 = outcode(fx0 >> 8, fy0 >> 8, xmin, ymin, xmax, ymax);
+		} else {
+			fx1 = x;
+			fy1 = y;
+			oc1 = outcode(fx1 >> 8, fy1 >> 8, xmin, ymin, xmax, ymax);
+		}
+	}
+
+	*x0 = fx0 >> 8;
+	*y0 = fy0 >> 8;
+	*x1 = fx1 >> 8;
+	*y1 = fy1 >> 8;
+	return 1;
+}
+
+void draw_line(int x0, int y0, int x1, int y1, uint32_t color)
+{
+	int i, dx, dy, x_inc, y_inc, error;
+	uint32_t *fb = fb_pixels;
+
+	fb += y0 * fb_width + x0;
+
+	dx = x1 - x0;
+	dy = y1 - y0;
+
+	if(dx >= 0) {
+		x_inc = 1;
+	} else {
+		x_inc = -1;
+		dx = -dx;
+	}
+	if(dy >= 0) {
+		y_inc = fb_width;
+	} else {
+		y_inc = -fb_width;
+		dy = -dy;
+	}
+
+	if(dx > dy) {
+		error = dy * 2 - dx;
+		for(i=0; i<=dx; i++) {
+			*fb = color;
+			if(error >= 0) {
+				error -= dx * 2;
+				fb += y_inc;
+			}
+			error += dy * 2;
+			fb += x_inc;
+		}
+	} else {
+		error = dx * 2 - dy;
+		for(i=0; i<=dy; i++) {
+			*fb = color;
+			if(error >= 0) {
+				error -= dy * 2;
+				fb += x_inc;
+			}
+			error += dx * 2;
+			fb += y_inc;
+		}
+	}
+}
+
+
+#define BLUR(w, h, pstep, sstep) \
+	for(i=0; i<h; i++) { \
+		int sum = sptr[0] * (rad + 1); \
+		int count = (rad * 2 + 1) << 8; \
+		int midsize = w - rad * 2; \
+		int firstpix = sptr[0]; \
+		int lastpix = sptr[pstep * (w - 1)]; \
+		/* add up the contributions for the -1 pixel */ \
+		for(j=0; j<rad; j++) { \
+			sum += sptr[pstep * j]; \
+		} \
+		/* first part adding sptr[rad] and subtracting sptr[0] */ \
+		for(j=0; j<=rad; j++) { \
+			sum += (int)sptr[pstep * rad] - firstpix; \
+			sptr += pstep; \
+			*dptr = scale * sum / count; \
+			dptr += pstep; \
+		} \
+		/* middle part adding sptr[rad] and subtracting sptr[-(rad+1)] */ \
+		for(j=1; j<midsize; j++) { \
+			sum += (int)sptr[pstep * rad] - (int)sptr[-(rad + 1) * pstep]; \
+			sptr += pstep; \
+			*dptr = scale * sum / count; \
+			dptr += pstep; \
+		} \
+		/* last part adding lastpix and subtracting sptr[-(rad+1)] */ \
+		for(j=0; j<rad; j++) { \
+			sum += lastpix - (int)sptr[-(rad + 1) * pstep]; \
+			sptr += pstep; \
+			*dptr = scale * sum / count; \
+			dptr += pstep; \
+		} \
+		sptr += sstep; \
+		dptr += sstep; \
+	}
+
+/* TODO bound blur rad to image size to avoid inner loop conditionals */
+/* TODO make version with pow2 (rad*2+1) to avoid div with count everywhere */
+void blur_grey_horiz(uint32_t *dest, uint32_t *src, int xsz, int ysz, int rad, int scale)
+{
+	int i, j;
+	unsigned char *dptr = (unsigned char*)dest;
+	unsigned char *sptr = (unsigned char*)src;
+
+	BLUR(xsz, ysz, 2, 0);
+}
+
+
+void blur_grey_vert(uint32_t *dest, uint32_t *src, int xsz, int ysz, int rad, int scale)
+{
+	int i, j;
+	unsigned char *dptr = (unsigned char*)dest;
+	unsigned char *sptr = (unsigned char*)src;
+	int pixel_step = xsz * 2;
+	int scanline_step = 2 - ysz * pixel_step;
+
+	BLUR(ysz, xsz, pixel_step, scanline_step);
+}
+
+void convimg_rgb24_rgb16(uint16_t *dest, unsigned char *src, int xsz, int ysz)
+{
+	int i;
+	int npixels = xsz * ysz;
+
+	for(i=0; i<npixels; i++) {
+		int r = *src++;
+		int g = *src++;
+		int b = *src++;
+		*dest++ = PACK_RGB16(r, g, b);
+	}
+}