_rti_raster_get_band_perimeter()

static rt_errorstate _rti_raster_get_band_perimeter ( rt_band  band, uint16_t *  trim  )

static

Definition at line 39 of file rt_geometry.c.

                                                             {
        uint16_t width = 0;
        uint16_t height = 0;
        int x = 0;
        int y = 0;
        int offset = 0;
        int done[4] = {0};
        double value = 0;
        int nodata = 0;
 
        assert(band != NULL);
        assert(band->raster != NULL);
        assert(trim != NULL);
 
        memset(trim, 0, sizeof(uint16_t) * 4);
 
        width = rt_band_get_width(band);
        height = rt_band_get_height(band);
 
        /* top */
        for (y = 0; y < height; y++) {
                for (offset = 0; offset < 3; offset++) {
                        /* every third pixel */
                        for (x = offset; x < width; x += 3) {
                                if (rt_band_get_pixel(band, x, y, &value, &nodata) != ES_NONE) {
                                        rterror("_rti_raster_get_band_perimeter: Could not get band pixel");
                                        return ES_ERROR;
                                }
 
                                RASTER_DEBUGF(4, "top (x, y, value, nodata) = (%d, %d, %f, %d)", x, y, value, nodata);
                                if (!nodata) {
                                        trim[0] = y;
                                        done[0] = 1;
                                        break;
                                }
                        }
 
                        if (done[0])
                                break;
                }
 
                if (done[0])
                        break;
        }
 
        /* right */
        for (x = width - 1; x >= 0; x--) {
                for (offset = 0; offset < 3; offset++) {
                        /* every third pixel */
                        for (y = offset; y < height; y += 3) {
                                if (rt_band_get_pixel(band, x, y, &value, &nodata) != ES_NONE) {
                                        rterror("_rti_raster_get_band_perimeter: Could not get band pixel");
                                        return ES_ERROR;
                                }
 
                                RASTER_DEBUGF(4, "right (x, y, value, nodata) = (%d, %d, %f, %d)", x, y, value, nodata);
                                if (!nodata) {
                                        trim[1] = width - (x + 1);
                                        done[1] = 1;
                                        break;
                                }
                        }
 
                        if (done[1])
                                break;
                }
 
                if (done[1])
                        break;
        }
 
        /* bottom */
        for (y = height - 1; y >= 0; y--) {
                for (offset = 0; offset < 3; offset++) {
                        /* every third pixel */
                        for (x = offset; x < width; x += 3) {
                                if (rt_band_get_pixel(band, x, y, &value, &nodata) != ES_NONE) {
                                        rterror("_rti_raster_get_band_perimeter: Could not get band pixel");
                                        return ES_ERROR;
                                }
 
                                RASTER_DEBUGF(4, "bottom (x, y, value, nodata) = (%d, %d, %f, %d)", x, y, value, nodata);
                                if (!nodata) {
                                        trim[2] = height - (y + 1);
                                        done[2] = 1;
                                        break;
                                }
                        }
 
                        if (done[2])
                                break;
                }
 
                if (done[2])
                        break;
        }
 
        /* left */
        for (x = 0; x < width; x++) {
                for (offset = 0; offset < 3; offset++) {
                        /* every third pixel */
                        for (y = offset; y < height; y += 3) {
                                if (rt_band_get_pixel(band, x, y, &value, &nodata) != ES_NONE) {
                                        rterror("_rti_raster_get_band_perimeter: Could not get band pixel");
                                        return ES_ERROR;
                                }
 
                                RASTER_DEBUGF(4, "left (x, , value, nodata) = (%d, %d, %f, %d)", x, y, value, nodata);
                                if (!nodata) {
                                        trim[3] = x;
                                        done[3] = 1;
                                        break;
                                }
                        }
 
                        if (done[3])
                                break;
                }
 
                if (done[3])
                        break;
        }
 
        RASTER_DEBUGF(4, "trim = (%d, %d, %d, %d)",
                trim[0], trim[1], trim[2], trim[3]);
 
        return ES_NONE;
}

References ES_ERROR, ES_NONE, RASTER_DEBUGF, rt_band_get_height(), rt_band_get_pixel(), rt_band_get_width(), rterror(), and trim().

Referenced by rt_raster_get_perimeter().

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