LCUI_API int Graph_FillAlpha( LCUI_Graph *src, uchar_t alpha )
{
int y, row_start;
LCUI_Rect src_rect;
/* 获取引用的区域在源图形中的有效区域 */
src_rect = Graph_GetValidRect( src );
/* 获取引用的源图指针 */
src = Graph_GetQuote( src );
if(! Graph_IsValid(src) ) {
return -1;
}
if( !Graph_HaveAlpha(src) ) {
return -2;
}
row_start = src_rect.x + src_rect.y * src->w;
for(y=0; y<src_rect.height; ++y) {
memset( &src->rgba[3][row_start],
alpha, src_rect.width*sizeof(uchar_t) );
row_start += src->w;
}
return 0;
}
LCUI_EXPORT(int) write_png(const char *file_name, LCUI_Graph *graph)
/* 将图像数据写入至png文件 */
{
#ifdef USE_LIBPNG
FILE *fp;
int j, i, temp, pos;
png_byte color_type;
png_structp png_ptr;
png_infop info_ptr;
png_bytep * row_pointers;
if(!Graph_IsValid(graph)) {
printf("write_png(): graph is not valid\n");
return -1;
}
/* create file */
fp = fopen(file_name, "wb");
if (!fp) {
printf("write_png(): File %s could not be opened for writing\n", file_name);
return -1;
}
/* initialize stuff */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
printf("write_png(): png_create_write_struct failed\n");
return -1;
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
printf("write_png(): png_create_info_struct failed\n");
return -1;
}
if (setjmp(png_jmpbuf(png_ptr))) {
printf("write_png(): Error during init_io\n");
return -1;
}
png_init_io(png_ptr, fp);
/* write header */
if (setjmp(png_jmpbuf(png_ptr))) {
printf("write_png(): Error during writing header\n");
return -1;
}
Graph_Lock(graph);
if(Graph_HaveAlpha(graph)) {
color_type = PNG_COLOR_TYPE_RGB_ALPHA;
} else {
color_type = PNG_COLOR_TYPE_RGB;
}
png_set_IHDR(png_ptr, info_ptr, graph->width, graph->height,
graph->bit_depth, color_type, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
png_write_info(png_ptr, info_ptr);
/* write bytes */
if (setjmp(png_jmpbuf(png_ptr)))
{
printf("write_png(): Error during writing bytes\n");
Graph_Unlock(graph);
return -1;
}
if(Graph_HaveAlpha(graph)) {
temp = (4 * graph->width);
} else {
temp = (3 * graph->width);
}
row_pointers = (png_bytep*)malloc(graph->height*sizeof(png_bytep));
for(i=0,pos=0; i < graph->height; i++) {
row_pointers[i] = (png_bytep)malloc(sizeof(unsigned char)*temp);
for(j=0; j < temp; ++pos) {
row_pointers[i][j++] = graph->rgba[0][pos]; // red
row_pointers[i][j++] = graph->rgba[1][pos]; // green
row_pointers[i][j++] = graph->rgba[2][pos]; // blue
if(Graph_HaveAlpha(graph)) {
row_pointers[i][j++] = graph->rgba[3][pos]; // alpha
}
}
}
png_write_image(png_ptr, row_pointers);
/* end write */
if (setjmp(png_jmpbuf(png_ptr))) {
printf("write_png(): Error during end of write\n");
Graph_Unlock(graph);
return -1;
}
png_write_end(png_ptr, NULL);
/* cleanup heap allocation */
for (j=0; j<graph->height; j++) {
free(row_pointers[j]);
}
free(row_pointers);
fclose(fp);
Graph_Unlock(graph);
#else
printf("warning: not PNG support!");
#endif
return 0;
}
LCUI_EXPORT(int) Graph_Rotate(LCUI_Graph *src, int rotate_angle, LCUI_Graph *des)
/*
* 功能：旋转图形
* 说明：指定旋转中心点坐标以及旋转角度，即可得到旋转后的图形
* 本源代码参考自互联网相关代码
* 算法有待优化完善。
*/
{
int width, height;
int new_width,new_height;
int m, n, z;
int src_x, src_y, des_x, des_y;
double fRotateAngle;
double fSina, fCosa;
double fSrcX1,fSrcY1,fSrcX2,fSrcY2,fSrcX3,fSrcY3,fSrcX4,fSrcY4;
double fDstX1,fDstY1,fDstX2,fDstY2,fDstX3,fDstY3,fDstX4,fDstY4;
double f1,f2;
if(!Graph_IsValid(src)) {
return -1;
}
// 获取图像的"宽度"（4的倍数）
width = src->width;
// 获取图像的高度
height = src->height;
// 将旋转角度从度转换到弧度
fRotateAngle = (double) radian(rotate_angle);
// 计算旋转角度的正弦
fSina = (double) sin((double)fRotateAngle);
// 计算旋转角度的余弦
fCosa = (double) cos((double)fRotateAngle);
// 计算原图的四个角的坐标（以图像中心为坐标系原点）
fSrcX1 = (double) (- (width - 1) / 2);
fSrcY1 = (double) ( (height - 1) / 2);
fSrcX2 = (double) ( (width - 1) / 2);
fSrcY2 = (double) ( (height - 1) / 2);
fSrcX3 = (double) (- (width - 1) / 2);
fSrcY3 = (double) (- (height - 1) / 2);
fSrcX4 = (double) ( (width - 1) / 2);
fSrcY4 = (double) (- (height - 1) / 2);
// 计算新图四个角的坐标（以图像中心为坐标系原点）
fDstX1 = fCosa * fSrcX1 + fSina * fSrcY1;
fDstY1 = -fSina * fSrcX1 + fCosa * fSrcY1;
fDstX2 = fCosa * fSrcX2 + fSina * fSrcY2;
fDstY2 = -fSina * fSrcX2 + fCosa * fSrcY2;
fDstX3 = fCosa * fSrcX3 + fSina * fSrcY3;
fDstY3 = -fSina * fSrcX3 + fCosa * fSrcY3;
fDstX4 = fCosa * fSrcX4 + fSina * fSrcY4;
fDstY4 = -fSina * fSrcX4 + fCosa * fSrcY4;
// 计算旋转后的图像实际宽度
new_width = (long) ( getmax( (int)fabs(fDstX4 - fDstX1), (int)fabs(fDstX3 - fDstX2) ) + 0.5);
// 计算旋转后的图像高度
new_height = (long) (getmax( (int)fabs(fDstY4 - fDstY1), (int)fabs(fDstY3 - fDstY2) ) + 0.5);
// 两个常数，这样不用以后每次都计算了
f1 = (double) (-0.5*(new_width-1)*fCosa-0.5*(new_height-1)*fSina+0.5*(width-1));
f2 = (double) (0.5*(new_width-1)*fSina-0.5*(new_height-1)*fCosa+0.5*(height-1));
if(Graph_IsValid(des)) {
Graph_Free(des);/* 先将这个内存释放 */
}
des->have_alpha = src->have_alpha;
// 分配内存，储存新的图形
if(Graph_Create(des, new_width, new_height) != 0) {
return -1;
}
// 针对图像每行进行操作
for(des_y = 0; des_y < new_height; ++des_y) {
m = new_width * des_y;
// 针对图像每列进行操作
for(des_x = 0; des_x < new_width; ++des_x) {
n = m + des_x;
// 计算该象素在源图中的坐标
src_y = (long) (-((double) des_x) * fSina + ((double) des_y) * fCosa + f2 + 0.5);
src_x = (long) ( ((double) des_x) * fCosa + ((double) des_y) * fSina + f1 + 0.5);
// 判断是否在源图范围内
if( (src_x >= 0) && (src_x < width)
&& (src_y >= 0) && (src_y < height)) {
// 指向源DIB第i0行，第j0个象素的指针
z = width * src_y + src_x;
des->rgba[0][n] = src->rgba[0][z];
des->rgba[1][n] = src->rgba[1][z];
des->rgba[2][n] = src->rgba[2][z];
if(Graph_HaveAlpha(des)) {
des->rgba[3][n] = src->rgba[3][z];
}
} else {
// 对于源图中没有的象素，直接赋值为255
des->rgba[0][n] = 255;
des->rgba[1][n] = 255;
des->rgba[2][n] = 255;
if(Graph_HaveAlpha(des)) {
des->rgba[3][n] = 0;
}
}
}
}
return 0;
}
