static void Graph_DrawLeftShadow( LCUI_PaintContext paint, LCUI_Rect *box,
LCUI_BoxShadow *shadow )
{
float v, a;
LCUI_Color color;
LCUI_Graph *graph;
int s, t, x, y, bound_x, bound_y;
LCUI_Rect shadow_area, box_area, paint_area, area;
s = 255;
t = BLUR_WIDTH(shadow);
v = 512.0/t;
a = 2*(v*t-s)/(t*t);
color = shadow->color;
box_area.x = BoxShadow_GetBoxX( shadow );
box_area.y = BoxShadow_GetBoxY( shadow );
box_area.w = BoxShadow_GetBoxWidth( shadow, box->w );
box_area.h = BoxShadow_GetBoxHeight( shadow, box->h );
shadow_area.x = BoxShadow_GetX( shadow );
shadow_area.y = BoxShadow_GetY( shadow ) + BLUR_WIDTH(shadow);
shadow_area.w = BLUR_WIDTH(shadow);
shadow_area.h = box_area.h + INNER_SHADOW_WIDTH(shadow)*2;
box_area.x += box->x;
box_area.y += box->y;
shadow_area.x += box->x;
shadow_area.y += box->y;
if( !LCUIRect_GetOverlayRect( &shadow_area, &paint->rect, &area ) ) {
return;
}
Graph_GetValidRect( &paint->canvas, &paint_area );
graph = Graph_GetQuote( &paint->canvas );
shadow_area.x -= paint->rect.x;
shadow_area.y -= paint->rect.y;
box_area.x -= paint->rect.x;
box_area.y -= paint->rect.y;
area.x -= paint->rect.x;
area.y -= paint->rect.y;
bound_x = area.x + area.width;
bound_y = area.y + area.height;
if( bound_x > paint_area.x + paint_area.width ) {
bound_x = paint_area.x + paint_area.width;
}
if( bound_y > paint_area.y + paint_area.height ) {
bound_y = paint_area.y + paint_area.height;
}
t -= area.x - shadow_area.x;
for( x = area.x; x < bound_x; ++x, --t ) {
color.alpha = (uchar_t)(s - (v*t - (a*t*t) / 2));
color.alpha *= shadow->color.a / 255.0;
for( y = area.y; y < bound_y; ++y ) {
if( y >= box_area.y && y < box_area.y + box_area.h &&
x >= box_area.x && x < box_area.x + box_area.w ) {
continue;
}
Graph_SetPixel( graph, x, y, color );
}
}
}
static void Graph_DrawTopShadow( LCUI_PaintContext paint, LCUI_Rect *box,
LCUI_BoxShadow *shadow )
{
float v, a;
int s, t, x, y, bound_x, bound_y;
LCUI_Color color;
LCUI_Graph *graph;
LCUI_Rect shadow_area, box_area, area;
box_area.x = BoxShadow_GetBoxX( shadow );
box_area.y = BoxShadow_GetBoxY( shadow );
box_area.w = BoxShadow_GetBoxWidth( shadow, box->w );
box_area.h = BoxShadow_GetBoxHeight( shadow, box->h );
/* 计算需要绘制上边阴影的区域 */
shadow_area.x = BoxShadow_GetX( shadow ) + BLUR_WIDTH(shadow);
shadow_area.y = BoxShadow_GetY( shadow );
shadow_area.w = box_area.w + INNER_SHADOW_WIDTH(shadow)*2;
shadow_area.h = BLUR_WIDTH(shadow);
color = shadow->color;
bound_x = shadow_area.x + shadow_area.w;
bound_y = shadow_area.y + shadow_area.h;
graph = Graph_GetQuote( &paint->canvas );
Graph_GetValidRect( &paint->canvas, &area );
if( !LCUIRect_GetOverlayRect( &area, &paint->rect, &area ) ) {
return;
}
/**
* 这里采用匀减速直线运动的公式： s = vt - at²/2
* 加速度 a 的求值公式为：a = 2x(vt - s)/t²
*/
s = 255;
t = BLUR_WIDTH(shadow);
v = 512.0/t;
a = 2*(v*t-s)/(t*t);
for( y=shadow_area.y; y<bound_y; ++y,--t ) {
/* 忽略不在有效区域内的像素 */
if( y < area.y || y >= area.y + area.h ) {
continue;
}
/* 计算当前行阴影的透明度 */
color.alpha = (uchar_t)(s-(v*t-(a*t*t)/2));
color.alpha *= shadow->color.a/255.0;
for( x=shadow_area.x; x<bound_x; ++x ) {
if( x < area.x || x >= area.x + area.w ) {
continue;
}
if( y >= box_area.y && y < box_area.y + box_area.h
&& x >= box_area.x && x < box_area.x + box_area.w ) {
continue;
}
Graph_SetPixel( graph, x, y, color );
}
}
}
static void Graph_DrawRightShadow( LCUI_PaintContext paint, LCUI_Rect *box,
LCUI_BoxShadow *shadow )
{
float v, a;
int s, t, x, y, bound_x, bound_y;
LCUI_Color color;
LCUI_Graph *graph;
LCUI_Rect shadow_area, box_area, area;
box_area.x = BoxShadow_GetBoxX( shadow );
box_area.y = BoxShadow_GetBoxY( shadow );
box_area.w = BoxShadow_GetBoxWidth( shadow, box->w );
box_area.h = BoxShadow_GetBoxHeight( shadow, box->h );
shadow_area.x = BoxShadow_GetX( shadow ) + SHADOW_WIDTH(shadow);
shadow_area.x += box_area.w + INNER_SHADOW_WIDTH(shadow);
shadow_area.y = BoxShadow_GetY( shadow ) + BLUR_WIDTH(shadow);
shadow_area.w = BLUR_WIDTH(shadow);
shadow_area.h = box_area.h + INNER_SHADOW_WIDTH(shadow)*2;
color = shadow->color;
bound_x = shadow_area.x + shadow_area.w;
bound_y = shadow_area.y + shadow_area.h;
graph = Graph_GetQuote( &paint->canvas );
Graph_GetValidRect( &paint->canvas, &area );
if( !LCUIRect_GetOverlayRect( &area, &paint->rect, &area ) ) {
return;
}
s = 255;
t = BLUR_WIDTH(shadow);
v = 512.0/t;
a = 2*(v*t-s)/(t*t);
for( t=0,x=shadow_area.x; x<bound_x; ++x,++t ) {
if( x < area.x || x >= area.x + area.w ) {
continue;
}
color.alpha = (uchar_t)(s-(v*t-(a*t*t)/2));
color.alpha *= shadow->color.a/255.0;
for( y=shadow_area.y; y<bound_y; ++y ) {
if( y < area.y || y >= area.y + area.h ) {
continue;
}
if( y >= box_area.y && y < box_area.y + box_area.h
&& x >= box_area.x && x < box_area.x + box_area.w ) {
continue;
}
Graph_SetPixel( graph, x, y, color );
}
}
}
/**
* 绘制上边阴影
* @param[in] paint 绘制上下文
* @param[in] box 可供绘制阴影的区域范围
* @param[in] shadow 阴影参数
*/
static void Graph_DrawTopShadow( LCUI_PaintContext paint, LCUI_Rect *box,
LCUI_BoxShadow *shadow )
{
float v, a;
LCUI_Color color;
LCUI_Graph *graph;
int s, t, x, y, bound_x, bound_y;
LCUI_Rect shadow_area, box_area, paint_area, area;
/**
* 这里采用匀减速直线运动的公式： s = vt - at²/2
* 加速度 a 的求值公式为：a = 2x(vt - s)/t²
*/
s = 255;
t = BLUR_WIDTH( shadow );
v = 512.0 / t;
a = 2 * (v*t - s) / (t*t);
color = shadow->color;
/* 计算阴影内框区域 */
box_area.x = BoxShadow_GetBoxX( shadow );
box_area.y = BoxShadow_GetBoxY( shadow );
box_area.w = BoxShadow_GetBoxWidth( shadow, box->w );
box_area.h = BoxShadow_GetBoxHeight( shadow, box->h );
/* 计算需要绘制的阴影区域 */
shadow_area.x = BoxShadow_GetX( shadow ) + BLUR_WIDTH(shadow);
shadow_area.y = BoxShadow_GetY( shadow );
shadow_area.w = box_area.w + INNER_SHADOW_WIDTH(shadow)*2;
shadow_area.h = BLUR_WIDTH(shadow);
/* 调整坐标 */
box_area.x += box->x;
box_area.y += box->y;
shadow_area.x += box->x;
shadow_area.y += box->y;
/* 如果阴影区域不在绘制范围内 */
if( !LCUIRect_GetOverlayRect( &shadow_area, &paint->rect, &area ) ) {
return;
}
/* 获取有效的绘制范围 */
Graph_GetValidRect( &paint->canvas, &paint_area );
graph = Graph_GetQuote( &paint->canvas );
/* 将坐标转换成相对于绘制区域 */
shadow_area.x -= paint->rect.x;
shadow_area.y -= paint->rect.y;
box_area.x -= paint->rect.x;
box_area.y -= paint->rect.y;
area.x -= paint->rect.x;
area.y -= paint->rect.y;
bound_x = area.x + area.width;
bound_y = area.y + area.height;
/* 避免超出绘制范围 */
if( bound_x > paint_area.x + paint_area.width ) {
bound_x = paint_area.x + paint_area.width;
}
if( bound_y > paint_area.y + paint_area.height ) {
bound_y = paint_area.y + paint_area.height;
}
t -= area.x - shadow_area.x;
for( y = area.y; y < bound_y; ++y, --t ) {
/* 计算当前行像素点的透明度 */
color.alpha = (uchar_t)(s - (v*t - (a*t*t) / 2));
color.alpha *= shadow->color.a / 255.0;
for( x = area.x; x < bound_x; ++x ) {
if( y >= box_area.y && y < box_area.y + box_area.h
&& x >= box_area.x && x < box_area.x + box_area.w ) {
continue;
}
Graph_SetPixel( graph, x, y, color );
}
}
}