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 }