SDL_shape.c File Reference

#include "../SDL_internal.h"
#include "SDL.h"
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_pixels.h"
#include "SDL_surface.h"
#include "SDL_shape.h"
#include "SDL_shape_internals.h"

Include dependency graph for SDL_shape.c:

Go to the source code of this file.

Functions
SDL_Window *	SDL_CreateShapedWindow (const char *title, unsigned int x, unsigned int y, unsigned int w, unsigned int h, Uint32 flags)
	Create a window that can be shaped with the specified position, dimensions, and flags. More...
SDL_bool	SDL_IsShapedWindow (const SDL_Window *window)
	Return whether the given window is a shaped window. More...
void	SDL_CalculateShapeBitmap (SDL_WindowShapeMode mode, SDL_Surface *shape, Uint8 *bitmap, Uint8 ppb)
static SDL_ShapeTree *	RecursivelyCalculateShapeTree (SDL_WindowShapeMode mode, SDL_Surface *mask, SDL_Rect dimensions)
SDL_ShapeTree *	SDL_CalculateShapeTree (SDL_WindowShapeMode mode, SDL_Surface *shape)
void	SDL_TraverseShapeTree (SDL_ShapeTree *tree, SDL_TraversalFunction function, void *closure)
void	SDL_FreeShapeTree (SDL_ShapeTree **shape_tree)
int	SDL_SetWindowShape (SDL_Window *window, SDL_Surface *shape, SDL_WindowShapeMode *shape_mode)
	Set the shape and parameters of a shaped window. More...
static SDL_bool	SDL_WindowHasAShape (SDL_Window *window)
int	SDL_GetShapedWindowMode (SDL_Window *window, SDL_WindowShapeMode *shape_mode)
	Get the shape parameters of a shaped window. More...

Function Documentation

RecursivelyCalculateShapeTree()

static SDL_ShapeTree* RecursivelyCalculateShapeTree ( SDL_WindowShapeMode  mode, SDL_Surface *  mask, SDL_Rect  dimensions  )

static

Definition at line 126 of file SDL_shape.c.

                                                                                              {
    int x = 0,y = 0;
    Uint8* pixel = NULL;
    Uint32 pixel_value = 0;
    Uint8 r = 0,g = 0,b = 0,a = 0;
    SDL_bool pixel_opaque = SDL_FALSE;
    int last_opaque = -1;
    SDL_Color key;
    SDL_ShapeTree* result = (SDL_ShapeTree*)SDL_malloc(sizeof(SDL_ShapeTree));
    SDL_Rect next = {0,0,0,0};
 
    for(y=dimensions.y;y<dimensions.y + dimensions.h;y++) {
        for(x=dimensions.x;x<dimensions.x + dimensions.w;x++) {
            pixel_value = 0;
            pixel = (Uint8 *)(mask->pixels) + (y*mask->pitch) + (x*mask->format->BytesPerPixel);
            switch(mask->format->BytesPerPixel) {
                case(1):
                    pixel_value = *pixel;
                    break;
                case(2):
                    pixel_value = *(Uint16*)pixel;
                    break;
                case(3):
                    pixel_value = *(Uint32*)pixel & (~mask->format->Amask);
                    break;
                case(4):
                    pixel_value = *(Uint32*)pixel;
                    break;
            }
            SDL_GetRGBA(pixel_value,mask->format,&r,&g,&b,&a);
            switch(mode.mode) {
                case(ShapeModeDefault):
                    pixel_opaque = (a >= 1 ? SDL_TRUE : SDL_FALSE);
                    break;
                case(ShapeModeBinarizeAlpha):
                    pixel_opaque = (a >= mode.parameters.binarizationCutoff ? SDL_TRUE : SDL_FALSE);
                    break;
                case(ShapeModeReverseBinarizeAlpha):
                    pixel_opaque = (a <= mode.parameters.binarizationCutoff ? SDL_TRUE : SDL_FALSE);
                    break;
                case(ShapeModeColorKey):
                    key = mode.parameters.colorKey;
                    pixel_opaque = ((key.r != r || key.g != g || key.b != b) ? SDL_TRUE : SDL_FALSE);
                    break;
            }
            if(last_opaque == -1)
                last_opaque = pixel_opaque;
            if(last_opaque != pixel_opaque) {
                const int halfwidth = dimensions.w / 2;
                const int halfheight = dimensions.h / 2;
 
                result->kind = QuadShape;
 
                next.x = dimensions.x;
                next.y = dimensions.y;
                next.w = halfwidth;
                next.h = halfheight;
                result->data.children.upleft = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
 
                next.x = dimensions.x + halfwidth;
                next.w = dimensions.w - halfwidth;
                result->data.children.upright = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
 
                next.x = dimensions.x;
                next.w = halfwidth;
                next.y = dimensions.y + halfheight;
                next.h = dimensions.h - halfheight;
                result->data.children.downleft = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
 
                next.x = dimensions.x + halfwidth;
                next.w = dimensions.w - halfwidth;
                result->data.children.downright = (struct SDL_ShapeTree *)RecursivelyCalculateShapeTree(mode,mask,next);
 
                return result;
            }
        }
    }
 
 
    /* If we never recursed, all the pixels in this quadrant have the same "value". */
    result->kind = (last_opaque == SDL_TRUE ? OpaqueShape : TransparentShape);
    result->data.shape = dimensions;
    return result;
}

References SDL_Rect::h, NULL, OpaqueShape, QuadShape, SDL_FALSE, SDL_GetRGBA, SDL_malloc, SDL_TRUE, ShapeModeBinarizeAlpha, ShapeModeColorKey, ShapeModeDefault, ShapeModeReverseBinarizeAlpha, TransparentShape, SDL_Rect::w, SDL_Rect::x, and SDL_Rect::y.

Referenced by SDL_CalculateShapeTree().

SDL_CalculateShapeBitmap()

void SDL_CalculateShapeBitmap	(	SDL_WindowShapeMode	mode,
		SDL_Surface *	shape,
		Uint8 *	bitmap,
		Uint8	ppb
	)

Definition at line 70 of file SDL_shape.c.

{
    int x = 0;
    int y = 0;
    Uint8 r = 0,g = 0,b = 0,alpha = 0;
    Uint8* pixel = NULL;
    Uint32 pixel_value = 0,mask_value = 0;
    int bytes_per_scanline = (shape->w + (ppb - 1)) / ppb;
    Uint8 *bitmap_scanline;
    SDL_Color key;
    if(SDL_MUSTLOCK(shape))
        SDL_LockSurface(shape);
    for(y = 0;y<shape->h;y++) {
        bitmap_scanline = bitmap + y * bytes_per_scanline;
        for(x=0;x<shape->w;x++) {
            alpha = 0;
            pixel_value = 0;
            pixel = (Uint8 *)(shape->pixels) + (y*shape->pitch) + (x*shape->format->BytesPerPixel);
            switch(shape->format->BytesPerPixel) {
                case(1):
                    pixel_value = *pixel;
                    break;
                case(2):
                    pixel_value = *(Uint16*)pixel;
                    break;
                case(3):
                    pixel_value = *(Uint32*)pixel & (~shape->format->Amask);
                    break;
                case(4):
                    pixel_value = *(Uint32*)pixel;
                    break;
            }
            SDL_GetRGBA(pixel_value,shape->format,&r,&g,&b,&alpha);
            switch(mode.mode) {
                case(ShapeModeDefault):
                    mask_value = (alpha >= 1 ? 1 : 0);
                    break;
                case(ShapeModeBinarizeAlpha):
                    mask_value = (alpha >= mode.parameters.binarizationCutoff ? 1 : 0);
                    break;
                case(ShapeModeReverseBinarizeAlpha):
                    mask_value = (alpha <= mode.parameters.binarizationCutoff ? 1 : 0);
                    break;
                case(ShapeModeColorKey):
                    key = mode.parameters.colorKey;
                    mask_value = ((key.r != r || key.g != g || key.b != b) ? 1 : 0);
                    break;
            }
            bitmap_scanline[x / ppb] |= mask_value << (x % ppb);
        }
    }
    if(SDL_MUSTLOCK(shape))
        SDL_UnlockSurface(shape);
}

References SDL_PixelFormat::Amask, SDL_PixelFormat::BytesPerPixel, SDL_Surface::format, SDL_Surface::h, NULL, SDL_Surface::pitch, SDL_Surface::pixels, SDL_GetRGBA, SDL_LockSurface, SDL_MUSTLOCK, SDL_UnlockSurface, ShapeModeBinarizeAlpha, ShapeModeColorKey, ShapeModeDefault, ShapeModeReverseBinarizeAlpha, and SDL_Surface::w.

SDL_CalculateShapeTree()

SDL_ShapeTree* SDL_CalculateShapeTree	(	SDL_WindowShapeMode	mode,
		SDL_Surface *	shape
	)

Definition at line 212 of file SDL_shape.c.

{
    SDL_Rect dimensions;
    SDL_ShapeTree* result = NULL;
 
    dimensions.x = 0;
    dimensions.y = 0;
    dimensions.w = shape->w;
    dimensions.h = shape->h;
 
    if(SDL_MUSTLOCK(shape))
        SDL_LockSurface(shape);
    result = RecursivelyCalculateShapeTree(mode,shape,dimensions);
    if(SDL_MUSTLOCK(shape))
        SDL_UnlockSurface(shape);
    return result;
}

References SDL_Rect::h, SDL_Surface::h, NULL, RecursivelyCalculateShapeTree(), SDL_LockSurface, SDL_MUSTLOCK, SDL_UnlockSurface, SDL_Rect::w, SDL_Surface::w, SDL_Rect::x, and SDL_Rect::y.

SDL_CreateShapedWindow()

SDL_Window* SDL_CreateShapedWindow	(	const char *	title,
		unsigned int	x,
		unsigned int	y,
		unsigned int	w,
		unsigned int	h,
		Uint32	flags
	)

Create a window that can be shaped with the specified position, dimensions, and flags.

Parameters

title	The title of the window, in UTF-8 encoding.
x	The x position of the window, SDL_WINDOWPOS_CENTERED, or SDL_WINDOWPOS_UNDEFINED.
y	The y position of the window, SDL_WINDOWPOS_CENTERED, or SDL_WINDOWPOS_UNDEFINED.
w	The width of the window.
h	The height of the window.
flags	The flags for the window, a mask of SDL_WINDOW_BORDERLESS with any of the following: SDL_WINDOW_OPENGL, SDL_WINDOW_INPUT_GRABBED, SDL_WINDOW_HIDDEN, SDL_WINDOW_RESIZABLE, SDL_WINDOW_MAXIMIZED, SDL_WINDOW_MINIMIZED, SDL_WINDOW_BORDERLESS is always set, and SDL_WINDOW_FULLSCREEN is always unset.

Returns

The window created, or NULL if window creation failed.

See also

SDL_DestroyWindow()

Definition at line 32 of file SDL_shape.c.

{
    SDL_Window *result = NULL;
    result = SDL_CreateWindow(title,-1000,-1000,w,h,(flags | SDL_WINDOW_BORDERLESS) & (~SDL_WINDOW_FULLSCREEN) & (~SDL_WINDOW_RESIZABLE) /* & (~SDL_WINDOW_SHOWN) */);
    if(result != NULL) {
        if (SDL_GetVideoDevice()->shape_driver.CreateShaper == NULL) {
            SDL_DestroyWindow(result);
            return NULL;
        }
        result->shaper = SDL_GetVideoDevice()->shape_driver.CreateShaper(result);
        if(result->shaper != NULL) {
            result->shaper->userx = x;
            result->shaper->usery = y;
            result->shaper->mode.mode = ShapeModeDefault;
            result->shaper->mode.parameters.binarizationCutoff = 1;
            result->shaper->hasshape = SDL_FALSE;
            return result;
        }
        else {
            SDL_DestroyWindow(result);
            return NULL;
        }
    }
    else
        return NULL;
}

References SDL_ShapeDriver::CreateShaper, NULL, SDL_CreateWindow, SDL_DestroyWindow, SDL_FALSE, SDL_GetVideoDevice(), SDL_WINDOW_BORDERLESS, SDL_WINDOW_FULLSCREEN, SDL_WINDOW_RESIZABLE, SDL_VideoDevice::shape_driver, ShapeModeDefault, and SDL_WindowShaper::userx.

SDL_FreeShapeTree()

void SDL_FreeShapeTree

(

SDL_ShapeTree **

shape_tree

)

Definition at line 245 of file SDL_shape.c.

{
    if((*shape_tree)->kind == QuadShape) {
        SDL_FreeShapeTree((SDL_ShapeTree **)(char*)&(*shape_tree)->data.children.upleft);
        SDL_FreeShapeTree((SDL_ShapeTree **)(char*)&(*shape_tree)->data.children.upright);
        SDL_FreeShapeTree((SDL_ShapeTree **)(char*)&(*shape_tree)->data.children.downleft);
        SDL_FreeShapeTree((SDL_ShapeTree **)(char*)&(*shape_tree)->data.children.downright);
    }
    SDL_free(*shape_tree);
    *shape_tree = NULL;
}

References NULL, QuadShape, and SDL_free.

SDL_GetShapedWindowMode()

int SDL_GetShapedWindowMode	(	SDL_Window *	window,
		SDL_WindowShapeMode *	shape_mode
	)

Get the shape parameters of a shaped window.

Parameters

window	The shaped window whose parameters should be retrieved.
shape_mode	An empty shape-mode structure to fill, or NULL to check whether the window has a shape.

Returns

0 if the window has a shape and, provided shape_mode was not NULL, shape_mode has been filled with the mode data, SDL_NONSHAPEABLE_WINDOW if the SDL_Window given is not a shaped window, or SDL_WINDOW_LACKS_SHAPE if the SDL_Window given is a shapeable window currently lacking a shape.

See also

SDL_WindowShapeMode

SDL_SetWindowShape

Definition at line 289 of file SDL_shape.c.

{
    if(window != NULL && SDL_IsShapedWindow(window)) {
        if(shape_mode == NULL) {
            if(SDL_WindowHasAShape(window))
                /* The window given has a shape. */
                return 0;
            else
                /* The window given is shapeable but lacks a shape. */
                return SDL_WINDOW_LACKS_SHAPE;
        }
        else {
            *shape_mode = window->shaper->mode;
            return 0;
        }
    }
    else
        /* The window given is not a valid shapeable window. */
        return SDL_NONSHAPEABLE_WINDOW;
}

References SDL_WindowShapeMode::mode, NULL, SDL_IsShapedWindow(), SDL_NONSHAPEABLE_WINDOW, SDL_WINDOW_LACKS_SHAPE, and SDL_WindowHasAShape().

SDL_IsShapedWindow()

SDL_bool SDL_IsShapedWindow

(

const SDL_Window *

window

)

Return whether the given window is a shaped window.

Parameters

window

The window to query for being shaped.

Returns

SDL_TRUE if the window is a window that can be shaped, SDL_FALSE if the window is unshaped or NULL.

See also

SDL_CreateShapedWindow

Definition at line 60 of file SDL_shape.c.

{
    if(window == NULL)
        return SDL_FALSE;
    else
        return (SDL_bool)(window->shaper != NULL);
}

References NULL, and SDL_FALSE.

Referenced by SDL_GetShapedWindowMode(), SDL_SetWindowShape(), and SDL_WindowHasAShape().

SDL_SetWindowShape()

int SDL_SetWindowShape	(	SDL_Window *	window,
		SDL_Surface *	shape,
		SDL_WindowShapeMode *	shape_mode
	)

Set the shape and parameters of a shaped window.

Parameters

window	The shaped window whose parameters should be set.
shape	A surface encoding the desired shape for the window.
shape_mode	The parameters to set for the shaped window.

Returns

0 on success, SDL_INVALID_SHAPE_ARGUMENT on an invalid shape argument, or SDL_NONSHAPEABLE_WINDOW if the SDL_Window given does not reference a valid shaped window.

See also

SDL_WindowShapeMode

SDL_GetShapedWindowMode.

Definition at line 258 of file SDL_shape.c.

{
    int result;
    if(window == NULL || !SDL_IsShapedWindow(window))
        /* The window given was not a shapeable window. */
        return SDL_NONSHAPEABLE_WINDOW;
    if(shape == NULL)
        /* Invalid shape argument. */
        return SDL_INVALID_SHAPE_ARGUMENT;
 
    if(shape_mode != NULL)
        window->shaper->mode = *shape_mode;
    result = SDL_GetVideoDevice()->shape_driver.SetWindowShape(window->shaper,shape,shape_mode);
    window->shaper->hasshape = SDL_TRUE;
    if(window->shaper->userx != 0 && window->shaper->usery != 0) {
        SDL_SetWindowPosition(window,window->shaper->userx,window->shaper->usery);
        window->shaper->userx = 0;
        window->shaper->usery = 0;
    }
    return result;
}

References NULL, SDL_GetVideoDevice(), SDL_INVALID_SHAPE_ARGUMENT, SDL_IsShapedWindow(), SDL_NONSHAPEABLE_WINDOW, SDL_SetWindowPosition, SDL_TRUE, SDL_ShapeDriver::SetWindowShape, and SDL_VideoDevice::shape_driver.

SDL_TraverseShapeTree()

void SDL_TraverseShapeTree	(	SDL_ShapeTree *	tree,
		SDL_TraversalFunction	function,
		void *	closure
	)

Definition at line 231 of file SDL_shape.c.

{
    SDL_assert(tree != NULL);
    if(tree->kind == QuadShape) {
        SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.upleft,function,closure);
        SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.upright,function,closure);
        SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.downleft,function,closure);
        SDL_TraverseShapeTree((SDL_ShapeTree *)tree->data.children.downright,function,closure);
    }
    else
        function(tree,closure);
}

References SDL_ShapeUnion::children, SDL_ShapeTree::data, SDL_QuadTreeChildren::downleft, SDL_QuadTreeChildren::downright, SDL_ShapeTree::kind, NULL, QuadShape, SDL_assert, SDL_QuadTreeChildren::upleft, and SDL_QuadTreeChildren::upright.

SDL_WindowHasAShape()

static SDL_bool SDL_WindowHasAShape ( SDL_Window *  window )

static

Definition at line 281 of file SDL_shape.c.

{
    if (window == NULL || !SDL_IsShapedWindow(window))
        return SDL_FALSE;
    return window->shaper->hasshape;
}

References NULL, SDL_FALSE, and SDL_IsShapedWindow().

Referenced by SDL_GetShapedWindowMode().