/**************************************************************************** * graphics/nxbe/nxbe_clipper.c * * Copyright (C) 2008-2009, 2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include "nxbe.h" /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ #define NX_INITIAL_STACKSIZE (32) /**************************************************************************** * Private Types ****************************************************************************/ /* This structure is a container that retains an associated between a * window instance and a rectangle. */ struct nxbe_cliprect_s { FAR struct nxbe_window_s *wnd; struct nxgl_rect_s rect; }; /* This is the stack of pending clip operations */ struct nxbe_clipstack_s { uint16_t npushed; /* Number of deferred rectangles in stack */ uint16_t mxrects; /* The capacity of the stack */ struct nxbe_cliprect_s *stack; /* The stack of deferred rectangles */ }; /**************************************************************************** * Private Data ****************************************************************************/ static const uint8_t g_nxcliporder[4][4] = { { NX_TOP_NDX, NX_LEFT_NDX, NX_RIGHT_NDX, NX_BOTTOM_NDX }, /* index = NX_CLIPORDER_TLRB */ { NX_TOP_NDX, NX_RIGHT_NDX, NX_LEFT_NDX, NX_BOTTOM_NDX }, /* NX_CLIPORDER_TRLB */ { NX_BOTTOM_NDX, NX_LEFT_NDX, NX_RIGHT_NDX, NX_TOP_NDX }, /* NX_CLIPORDER_BLRT */ { NX_BOTTOM_NDX, NX_RIGHT_NDX, NX_LEFT_NDX, NX_TOP_NDX } /* NX_CLIPORDER_BRLT */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: nxbe_pushrectangle ****************************************************************************/ static inline void nxbe_pushrectangle(FAR struct nxbe_clipstack_s *stack, FAR struct nxbe_window_s *wnd, FAR const struct nxgl_rect_s *rect) { /* Check if there is room on the stack to hold another rectangle */ if ((stack->npushed + 1) > stack->mxrects) { /* No then we will need to reallocate the stack to hold more */ int mxrects = stack->mxrects ? 2 * stack->mxrects : NX_INITIAL_STACKSIZE; struct nxbe_cliprect_s *newstack; newstack = kmm_realloc(stack->stack, sizeof(struct nxbe_cliprect_s) * mxrects); if (!newstack) { gdbg("Failed to reallocate stack\n"); return; } stack->stack = newstack; stack->mxrects = mxrects; } /* Then push the new rectangle onto the stack */ stack->stack[stack->npushed].wnd = wnd; nxgl_rectcopy(&stack->stack[stack->npushed].rect, rect); stack->npushed++; } /**************************************************************************** * Name: nxbe_poprectangle ****************************************************************************/ static inline bool nxbe_poprectangle(struct nxbe_clipstack_s *stack, FAR struct nxbe_window_s **wnd, struct nxgl_rect_s *rect) { if (stack->npushed > 0) { stack->npushed--; *wnd = stack->stack[stack->npushed].wnd; nxgl_rectcopy(rect, &stack->stack[stack->npushed].rect); return true; } return false; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nxbe_clipper * * Descripton: * Perform flexible clipping operations. Callbacks are executed for * each oscured and visible portions of the window. * * Input Parameters: * wnd - The window to be clipped. * rect - The region of concern within the window * order - Specifies the order to process the parts of the non-intersecting * sub-rectangles. * cops - The callbacks to handle obscured and visible parts of the * sub-rectangles. * plane - The raster operations to be used by the callback functions. * These may vary with different color formats. * * Returned Value: * None * ****************************************************************************/ void nxbe_clipper(FAR struct nxbe_window_s *wnd, FAR const struct nxgl_rect_s *dest, uint8_t order, FAR struct nxbe_clipops_s *cops, FAR struct nxbe_plane_s *plane) { struct nxbe_clipstack_s stack; FAR struct nxbe_window_s *currw; struct nxgl_rect_s rect; struct nxgl_rect_s obscuredrect; struct nxgl_rect_s currbounds; struct nxgl_rect_s nonoverlapped[4]; int i; /* Initialize the stack where we will keep deferred rectangle operations */ stack.npushed = 0; stack.mxrects = 0; stack.stack = NULL; /* Loop until there are no further pending operations */ nxgl_rectcopy(&rect, dest); /* Start with the whole dest rectangle */ do { /* Loop for every window from the current window and above. Only windows * above the current window can obscure the current window */ for (currw = wnd; currw; currw = currw->above) { /* Does the current window overlap the dest rectangle? */ currbounds = currw->bounds; if (nxgl_rectoverlap(&rect, &currbounds)) { /* Yes.. then it obscures all or part of the dest rectangle. * Divide the potentially visible, non-overlapping regions into 4 * smaller rectangles and push them onto the stack for processing * on the next time through the outer loop. */ nxgl_nonintersecting(nonoverlapped, &rect, &currbounds); for (i = 3; i >= 0; i--) { /* Push the rectangles in the order specific by the input * argument of that name. */ struct nxgl_rect_s *candidate = &nonoverlapped[g_nxcliporder[order][i]]; if (!nxgl_nullrect(candidate)) { nxbe_pushrectangle(&stack, currw->above, candidate); } } /* Now performed any required processing on the obscurred, * overlapped region. */ nxgl_rectintersect(&obscuredrect, &rect, &currbounds); cops->obscured(cops, plane, &obscuredrect); /* Break out of the loop to process the pushed rectangles */ break; } } /* If there are no other windows overlapping this rectangle, then this * rectangular region must be visible. */ if (!currw && !nxgl_nullrect(&rect)) { cops->visible(cops, plane, &rect); } } while (nxbe_poprectangle(&stack, &wnd, &rect)); /* Done! If any stack was allocated, then free it before exit-ting */ if (stack.stack) { kmm_free(stack.stack); } } /**************************************************************************** * Name: nxbe_clipnull * * Descripton: * The do-nothing clipping callback function * ****************************************************************************/ void nxbe_clipnull(FAR struct nxbe_clipops_s *cops, FAR struct nxbe_plane_s *plane, FAR const struct nxgl_rect_s *rect) { }