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Diffstat (limited to 'nuttx/graphics/nxbe/nxbe_clipper.c')
| -rw-r--r-- | nuttx/graphics/nxbe/nxbe_clipper.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/nuttx/graphics/nxbe/nxbe_clipper.c b/nuttx/graphics/nxbe/nxbe_clipper.c new file mode 100644 index 000000000..580c8bc4c --- /dev/null +++ b/nuttx/graphics/nxbe/nxbe_clipper.c @@ -0,0 +1,278 @@ +/**************************************************************************** + * graphics/nxbe/nxbe_clipper.c + * + * Copyright (C) 2008-2009 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 <nuttx/config.h> + +#include <stdint.h> +#include <stdbool.h> +#include <stdlib.h> +#include <debug.h> + +#include <nuttx/nx/nxglib.h> +#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 */ +}; + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/**************************************************************************** + * 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 hole more */ + + int mxrects = stack->mxrects ? 2 * stack->mxrects : NX_INITIAL_STACKSIZE; + struct nxbe_cliprect_s *newstack; + + newstack = 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) + { + 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) +{ +} + |