cocos2dx版本为3.10
1.具体原理和代码可以参考博文《利用shader改变图片色相Hue》，下面的代码根据该博文进行整理优化。
基本原理就是将RGB值转换为HSL值后加上输入的HSL值，再转换为RGB值。
2.spine变色的思路有三种：
①spine::SkeletonAnimation调用shader
②读取spine对应的atlas文件，分析该文件得到所需的png图片，将该图片读入内存，修改内存中像素颜色，然后生成texture赋值给spine中的spAtlas->pages->rendererObject
③读取spine对应的atlas文件，分析该文件得到所需的png图片，将该图片读入内存，修改内存中像素颜色，保存为新的png图片；读取atlas文件，修改里面png名字为新png图片名字，保存为新的atlas文件；spine创建时使用新的png图片和新的atlas文件；
以上三种方法都可行，但在实现过程中我选择使用了第③种方法；
第①种方法简单易用，但是打包到一些低端的android手机时发现掉帧很厉害，所以才会有第②和第③种方法。
第②种方法经过测试也是可行的，但是破坏了spine的正常创建流程，导致对源码的修改过于复杂容易导致各种问题。
第③种方法独立在正常创建spine流程之前，更稳当可控。
3.根据资料色相H值的范围在[0,360],饱和度S值的范围在[0,1],明度L值的范围在[0,1]；在PhotoShop中(快捷键ctrl+u)可调值范围为色相H[-180,180],饱和度A[-100,100],明度I[-100,100]；
所以在代码中,H值不进行转换，S值和L值都除以100；在实际测试过程中发现，PS调试出来的效果和程序得到的效果在S/L不为0的情况下还是有区别的，具体原因不懂，估计可能是算法不一致吧。
4.第①种方法shader
①shader代码
1 #ifdef GL_ES 2 precision mediump float; 3 #endif
4 varying vec2 v_texCoord; 5 uniform float u_dH; 6 uniform float u_dS; 7 uniform float u_dL; 8 void main() { 9 vec4 texColor = texture2D(CC_Texture0, v_texCoord); 10 float r = texColor.r; 11 float g = texColor.g; 12 float b = texColor.b; 13 float a = texColor.a; 14 //convert rgb to hsl
15 float h; 16 float s; 17 float l; 18 { 19 float max = max(max(r, g), b); 20 float min = min(min(r, g), b); 21 //----h
22 if (max == min){ 23 h = 0.0; 24 } 25 else if (max == r&&g >= b){ 26 h = 60.0*(g - b) / (max - min) + 0.0; 27 } 28 else if (max == r&&g < b){ 29 h = 60.0*(g - b) / (max - min) + 360.0; 30 } 31 else if (max == g){ 32 h = 60.0*(b - r) / (max - min) + 120.0; 33 } 34 else if (max == b){ 35 h = 60.0*(r - g) / (max - min) + 240.0; 36 } 37 //----l
38 l = 0.5*(max + min); 39 //----s
40 if (l == 0.0 || max == min){ 41 s = 0.0; 42 } 43 else if (0.0 <= l&&l <= 0.5){ 44 s = (max - min) / (2.0*l); 45 } 46 else if (l > 0.5){ 47 s = (max - min) / (2.0 - 2.0*l); 48 } 49 } 50 //(h,s,l)+(dH,dS,dL) -> (h,s,l)
51 h = h + u_dH; 52 s = min(1.0, max(0.0, s + u_dS)); 53 l = l + u_dL; 54 //convert (h,s,l) to rgb and got final color
55 vec4 finalColor; 56 { 57 float q; 58 if (l < 0.5){ 59 q = l*(1.0 + s); 60 } 61 else if (l >= 0.5){ 62 q = l + s - l*s; 63 } 64 float p = 2.0*l - q; 65 float hk = h / 360.0; 66
67 float t[3]; 68 t[0] = hk + 1.0 / 3.0; 69 t[1] = hk; 70 t[2] = hk - 1.0 / 3.0; 71
72 float c[3]; 73 for (int i = 0; i < 3; i++){ 74 if (t[i] < 0.0)t[i] += 1.0; 75 if (t[i] > 1.0)t[i] -= 1.0; 76
77 if (t[i] < 1.0 / 6.0){ 78 c[i] = p + ((q - p)*6.0*t[i]); 79 } 80 else if (1.0 / 6.0 <= t[i] && t[i] < 0.5){ 81 c[i] = q; 82 } 83 else if (0.5 <= t[i] && t[i] < 2.0 / 3.0){ 84 c[i] = p + ((q - p)*6.0*(2.0 / 3.0 - t[i])); 85 } 86 else{ 87 c[i] = p; 88 } 89 } 90 finalColor = vec4(c[0], c[1], c[2], a); 91 } 92 finalColor += vec4(u_dL, u_dL, u_dL, 0.0); 93 gl_FragColor = finalColor; 94 }
②调用代码
1 auto glprogram = GLProgram::createWithByteArrays(ccPositionTextureColor_vert, shader_content);//如果是Sprite使用这个Shader，则需要换为ccPositionTextureColor_noMVP_vert
2 GLProgramState* glState = GLProgramState::getOrCreateWithGLProgram(glprogram); 3
4 glState->setUniformFloat("u_dH", h); 5 glState->setUniformFloat("u_dS", s / 100); 6 glState->setUniformFloat("u_dL", l / 100); 7
8 skeleton_animation->setGLProgramState(glState);
5.第③种方法创建新的png文件和atlas文件
①创建新png文件函数(这里的函数实现和参考博文《利用shader改变图片色相Hue》的实现不一样，参考博文只传了一个H值，这里是直接根据shader进行的移植修改)
1 Image* create_new_image_hsl(Image* image, float u_dH, float u_dS, float u_dL){ 2 u_dH = u_dH; 3 u_dS = u_dS / 100.0f; 4 u_dL = u_dL / 100.0f; 5
6 bool hasAlpha = image->hasAlpha(); 7 Texture2D::PixelFormat pixelFormat = image->getRenderFormat(); 8 int bit_per_pixel = image->getBitPerPixel(); //每像素多少位
9 unsigned int length = image->getWidth()*image->getHeight(); 10
11 if (hasAlpha){ 12 //只处理了RGBA8888的格式
13 if (pixelFormat == Texture2D::PixelFormat::RGBA8888){ 14 unsigned int* inPixel32 = (unsigned int*)image->getData(); 15 for (unsigned int i = 0; i < length; ++i, ++inPixel32) 16 { 17 unsigned char cr = (*inPixel32 >> 0) & 0xFF; // R
18 unsigned char cg = (*inPixel32 >> 8) & 0xFF; // G
19 unsigned char cb = (*inPixel32 >> 16) & 0xFF; // B
20 unsigned char ca = (*inPixel32 >> 24) & 0xFF; // A 21 //透明图层不做处理
22 if (ca){ 23 float r = cr*1.0f / 0xFF; 24 float g = cg*1.0f / 0xFF; 25 float b = cb*1.0f / 0xFF; 26
27 float h = 0; 28 float s = 0; 29 float l = 0; 30 { 31 float max = r > g ? r : g; 32 max = max > b ? max : b; 33
34 float min = r < g ? r : g; 35 min = min < b ? min : b; 36
37 //----h
38 if (max == min){ 39 h = 0; 40 } 41 else if (max == r && g >= b){ 42 h = 60.0f*(g - b) / (max - min); 43 } 44 else if (max == r && g < b){ 45 h = 60.0f*(g - b) / (max - min) + 360.0f; 46 } 47 else if (max == g){ 48 h = 60.0f*(b - r) / (max - min) + 120.0f; 49 } 50 else if (max == b){ 51 h = 60.0f*(r - g) / (max - min) + 240.0f; 52 } 53 //----l
54 l = 0.5f*(max + min); 55 //----s
56 if (l == 0 || max == min){ 57 s = 0; 58 } 59 else if (0 <= l&&l <= 0.5f){ 60 s = (max - min) / (2.0f*l); 61 } 62 else if (l > 0.5f){ 63 s = (max - min) / (2.0f - 2.0f*l); 64 } 65 } 66 //(h,s,l)+(dH,dS,dL) -> (h,s,l)
67 h = h + u_dH; 68 s = 0 > s + u_dS ? 0 : s + u_dS; 69 s = s < 1.0f ? s : 1.0f; 70
71 l = l + u_dL; 72 //convert (h,s,l) to rgb and got final color 73
74 //vec4 finalColor;
75 { 76 float q; 77 if (l < 0.5f){ 78 q = l*(1.0f + s); 79 } 80 else if (l >= 0.5f){ 81 q = l + s - l*s; 82 } 83 float p = 2.0f*l - q; 84 float hk = h / 360.0f; 85
86 float t[3] = {}; 87 t[0] = hk + 1.0f / 3.0f; 88 t[1] = hk; 89 t[2] = hk - 1.0f / 3.0f; 90
91 float c[3] = {}; 92 for (int i = 0; i < 3; i++){ 93 if (t[i] < 0){ 94 t[i] += 1.0f; 95 } 96 if (t[i] > 1.0f){ 97 t[i] -= 1.0f; 98 } 99
100 if (t[i] < 1.0f / 6.0f){ 101 c[i] = p + ((q - p)*6.0f*t[i]); 102 } 103 else if (1.0f / 6.0f <= t[i] && t[i] < 0.5f){ 104 c[i] = q; 105 } 106 else if (0.5f <= t[i] && t[i] < 2.0f / 3.0f){ 107 c[i] = p + ((q - p)*6.0f*(2.0f / 3.0f - t[i])); 108 } 109 else{ 110 c[i] = p; 111 } 112 } 113 //finalColor = vec4(c[0], c[1], c[2], a);
114
115 r = c[0]; 116 g = c[1]; 117 b = c[2]; 118 } 119
120 //finalColor += vec4(u_dL, u_dL, u_dL, 0.0);
121 r += u_dL; 122 g += u_dL; 123 b += u_dL; 124 //限制rgb值的有效范围
125 if (r > 1.0f) r = 1.0f; 126 if (g > 1.0f) g = 1.0f; 127 if (b > 1.0f) b = 1.0f; 128 if (r < 0) r = 0; 129 if (g < 0) g = 0; 130 if (b < 0) b = 0; 131
132 unsigned char final_r = r * 0xFF; 133 unsigned char final_g = g * 0xFF; 134 unsigned char final_b = b * 0xFF; 135 unsigned char final_a = ca; 136
137
138 unsigned int val = final_a; 139 val = val << 8; 140 val |= final_b; 141 val = val << 8; 142 val |= final_g; 143 val = val << 8; 144 val |= final_r; 145
146 *inPixel32 = val; 147 } 148 } 149 } 150 } 151
152 return image; 153 }
②分析atlas文件，得到对应的png文件，并生成新png文件和atlas文件
1 bool create_new_png_and_atlas(const char* atlas_name_no_extension, float u_dH, float u_dS, float u_dL) 2 { 3 bool ret = false; 4
5 std::string atlas_name = atlas_name_no_extension; 6 atlas_name += ".atlas"; 7 std::string atlas_file_full_name = FileUtils::getInstance()->fullPathForFilename(atlas_name); 8 Data data = FileUtils::getInstance()->getDataFromFile(atlas_file_full_name); 9
10 if (!data.isNull()){ 11 std::string writeable_path = FileUtils::getInstance()->getWritablePath(); 12
13 char* orginal_atlas_content = new char[data.getSize()](); 14 memcpy(orginal_atlas_content, data.getBytes(), data.getSize()); 15
16 char sz_new_atlas_path[256] = {}; 17 sprintf(sz_new_atlas_path, "%s%s_%d_%d_%d.atlas", writeable_path.c_str(), atlas_name_no_extension, (int)u_dH, (int)u_dS, (int)u_dL); 18
19 //为了保证大小，创建一个两倍大小的内存大小(这里可以适当减少大小)
20 unsigned char* new_atlas_content = new unsigned char[2 * data.getSize()](); 21 memset(new_atlas_content, 0, 2 * data.getSize()); 22
23 //分析得出png文件名字，可能有分为多个png的情况
24 std::vector<std::string> png_no_extension_list; 25 int line_start_idx = 0, line_end_idx = 0; 26 int orginal_content_start_idx = 0, new_content_idx = 0, new_content_total_len = 0; 27
28 for (int i = 0; i < data.getSize(); ++i){ 29 line_end_idx = i; 30
31 //每一行判断是否为png
32 if (orginal_atlas_content[i] == '\n'){ 33 int line_len = line_end_idx - line_start_idx; 34
35 //处理是图片的情况
36 if (line_len > 4 && orginal_atlas_content[line_end_idx - 4] == '.' &&
37 (orginal_atlas_content[line_end_idx - 3] == 'p' || orginal_atlas_content[line_end_idx - 3] == 'P') &&
38 (orginal_atlas_content[line_end_idx - 2] == 'n' || orginal_atlas_content[line_end_idx - 2] == 'N') &&
39 (orginal_atlas_content[line_end_idx - 1] == 'g' || orginal_atlas_content[line_end_idx - 1] == 'G')){ 40 //将png行前面的数据拷贝进来
41 int cpy_len = line_start_idx - orginal_content_start_idx; 42 if (cpy_len > 0){ 43 memcpy(new_atlas_content + new_content_idx, orginal_atlas_content + orginal_content_start_idx, cpy_len); 44 new_content_idx += cpy_len; 45 new_content_total_len += cpy_len; 46 } 47
48 //没有后缀的png的名字
49 char png_name_no_extension[256] = {}; 50 memcpy(png_name_no_extension, orginal_atlas_content + line_start_idx, line_len - 4); 51 png_no_extension_list.push_back(png_name_no_extension); 52
53 //记录列表
54 char sz_new_png_name[256] = {}; 55 sprintf(sz_new_png_name, "%s_%d_%d_%d.png\n", png_name_no_extension, (int)u_dH, (int)u_dS, (int)u_dL); 56
57 //将图片名字写入新内容
58 cpy_len = strlen(sz_new_png_name); 59 memcpy(new_atlas_content + new_content_idx, sz_new_png_name, cpy_len); 60 new_content_idx += cpy_len; 61 new_content_total_len += cpy_len; 62
63 orginal_content_start_idx = line_end_idx + 1; 64 } 65
66 line_start_idx = line_end_idx + 1; 67 } 68 } 69
70 //将最后一个png行到最后那部分数据也拷贝进来
71 if (data.getSize() > orginal_content_start_idx){ 72 int cpy_len = data.getSize() - orginal_content_start_idx; 73 memcpy(new_atlas_content + new_content_idx, orginal_atlas_content + orginal_content_start_idx, cpy_len); 74 new_content_total_len += cpy_len; 75 } 76
77
78 Data data; 79 data.copy(new_atlas_content, new_content_total_len); 80
81 if (!FileUtils::getInstance()->writeDataToFile(data, sz_new_atlas_path)){ 82 cocos2d::log("========!!! save file %s error !!!========.", sz_new_atlas_path); 83 } 84 else{ 85 ret = true; 86 } 87
88 data.clear(); 89
90 delete[]orginal_atlas_content; 91 delete[]new_atlas_content; 92
93 if (png_no_extension_list.size() <= 0){ 94 cocos2d::log("========!!! png_name_list is empty error !!!========."); 95 return false; 96 } 97
98 if (!ret){ 99 return false; 100 } 101
102 //写入新图片
103 for (std::vector<std::string>::iterator it = png_no_extension_list.begin(); it != png_no_extension_list.end(); ++it){ 104 if (!ret){ 105 break; 106 } 107
108 char sz_new_png_path[256] = {}; 109 sprintf(sz_new_png_path, "%s%s_%d_%d_%d.png", writeable_path.c_str(), it->c_str(), (int)u_dH, (int)u_dS, (int)u_dL); 110
111 char sz_png_name[256] = {}; 112 sprintf(sz_png_name, "%s.png", it->c_str()); 113 std::string png_file_full_name = FileUtils::getInstance()->fullPathForFilename(sz_png_name); 114
115 Image* image = new Image(); 116 if (image->initWithImageFile(png_file_full_name)){ 117 if (Image* new_image = create_new_image_hsl(image, u_dH, u_dS, u_dL)){ 118 if (!new_image->saveToFile(sz_new_png_path, false)){ 119 cocos2d::log("========!!! save file %s error !!!========.", sz_new_png_path); 120 ret = false; 121 } 122 } 123 else{ 124 cocos2d::log("========!!! create_new_image_hsl %s error !!!========.", sz_new_png_path); 125 ret = false; 126 } 127 } 128 else{ 129 cocos2d::log("========!!! initWithImageFile %s error !!!========.", png_file_full_name.c_str()); 130 ret = false; 131 } 132
133 delete image; 134 } 135 } 136
137 return ret; 138 }
6.实现效果
①原图
②PhotoShop中调到115,0,0的效果
③传入参数115,0,0后创建新Image的效果
可以看到，使用ps修改的效果和程序输出的效果基本一样。
以上，完。