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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);
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
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
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 void create_new_png_atlas_hls(const std::string& atlasFile, float u_dH, float u_dS, float u_dL)
2 {
3 std::string atlas_file_full_name = FileUtils::getInstance()->fullPathForFilename(atlasFile);
4 Data data = FileUtils::getInstance()->getDataFromFile(atlas_file_full_name);
5
6 char* bytes = new char[data.getSize()]();
7 memcpy(bytes, data.getBytes(), data.getSize());
8
9 //遍历得到第一个‘\n‘，则是png名字
10 int start_idx = 0, end_idx = 0;
11 for (int i = 0; i < data.getSize(); ++i){
12 end_idx = i;
13
14 if (bytes[i] == ‘\n‘){
15 //判断是否png
16 int len = end_idx - start_idx;
17 if (len > 4 && bytes[end_idx - 4] == ‘.‘ &&
18 (bytes[end_idx - 3] == ‘p‘ || bytes[end_idx - 3] == ‘P‘) &&
19 (bytes[end_idx - 2] == ‘n‘ || bytes[end_idx - 2] == ‘N‘) &&
20 (bytes[end_idx - 1] == ‘g‘ || bytes[end_idx - 1] == ‘G‘)){
21
22 //新文件路径
23 char sz_atlas_path[256] = {};
24 memcpy(sz_atlas_path, atlas_file_full_name.c_str(), atlas_file_full_name.size() - 6);
25 std::string new_atlas_path = StringUtils::format("%s_%d_%d_%d.atlas", sz_atlas_path, (int)u_dH, (int)u_dS, (int)u_dL);
26
27 //png的名字
28 char png_name[256] = {};
29 memcpy(png_name, bytes + start_idx, len - 4);
30 std::string new_png_name = StringUtils::format("%s_%d_%d_%d.png", png_name, (int)u_dH, (int)u_dS, (int)u_dL);
31
32 //根据新名字生成新的atlas文件
33 unsigned char* new_atlas_content = new unsigned char[data.getSize() + new_png_name.size()]();
34 int len = 0;
35 memcpy(new_atlas_content, bytes, start_idx);
36 len += start_idx;
37 memcpy(new_atlas_content + len, new_png_name.c_str(), new_png_name.size());
38 len += new_png_name.size();
39 if (end_idx < data.getSize()){
40 memcpy(new_atlas_content + len, bytes + end_idx, data.getSize() - end_idx);
41 }
42 len += (data.getSize() - end_idx);
43
44 Data data;
45 data.copy(new_atlas_content, len);
46
47 if (!FileUtils::getInstance()->writeDataToFile(data, new_atlas_path)){
48 cocos2d::log("save file %s error.", new_atlas_path.c_str());
49 }
50
51 data.clear();
52 delete[]new_atlas_content;
53
54
55 //写入新的图片
56 std::string png_file_full_name = FileUtils::getInstance()->fullPathForFilename(StringUtils::format("%s.png", png_name));
57 char sz_png_path[256] = {};
58 memcpy(sz_png_path, png_file_full_name.c_str(), png_file_full_name.size() - 4);
59 std::string new_png_path = StringUtils::format("%s_%d_%d_%d.png", sz_png_path, (int)u_dH, (int)u_dS, (int)u_dL);
60
61 Image* image = new Image();
62 image->initWithImageFile(png_file_full_name);
63
64 Image* new_image = create_new_image_hsl(image, u_dH, u_dS, u_dL);
65 if (!new_image->saveToFile(new_png_path, false)){
66 cocos2d::log("save file %s error.", new_png_path.c_str());
67 }
68 delete image;
69
70 break;
71 }
72
73 start_idx = i + 1;
74 }
75 }
76 delete[]bytes;
77 }
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原文地址：http://www.cnblogs.com/chevin/p/5668364.html
