Cocos2d-x shader学习1: 灰度shader
灰度shader最近在学习shader,就把cocos2d-x 3.x版本中的很简单也很常用的灰度shader拿出来学习一下。 #ifdef GL_ES
precision mediump float; // ES版本的精度限定符,精度变低后可以提高效率
#endif
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
void main(void)
vec4 c = texture2D(CC_Texture0,v_texCoord);
gl_FragColor.xyz = vec3(0.2126*c.r + 0.7152*c.g + 0.0722*c.b);
gl_FragColor.w = c.w;
}
代码分析
下面是顶点着色器的代码: const char* ccPositionTextureColor_noMVP_vert = STRINGIFY(
attribute vec4 a_position;
attribute vec2 a_texCoord;
attribute vec4 a_color;
n#ifdef GL_ESn
varying lowp vec4 v_fragmentColor;
varying mediump vec2 v_texCoord;
n#elsen
varying vec4 v_fragmentColor;
varying vec2 v_texCoord;
n#endifn
void main()
{
gl_Position = CC_PMatrix * a_position;
v_fragmentColor = a_color;
v_texCoord = a_texCoord;
}
);
static const char * COCOS2D_SHADER_UNIFORMS =
"uniform mat4 CC_PMatrix;n"
"uniform mat4 CC_MVMatrix;n"
"uniform mat4 CC_MVPMatrix;n"
"uniform mat3 CC_NormalMatrix;n"
"uniform vec4 CC_Time;n"
"uniform vec4 CC_SinTime;n"
"uniform vec4 CC_CosTime;n"
"uniform vec4 CC_Random01;n"
"uniform sampler2D CC_Texture0;n"
"uniform sampler2D CC_Texture1;n"
"uniform sampler2D CC_Texture2;n"
"uniform sampler2D CC_Texture3;n"
"//CC INCLUDES ENDnn";
这些变量在shader里面如果没有用到的话,会被引擎给优化掉。
这个shader很简单,就是改变了一下rgb的值。 使用示例在cocos2dx 3.x版本中sprite变灰的代码例子: auto sprite = Sprite::create("HelloWorld.png");
sprite->setGLProgramState(GLProgramState::getOrCreateWithGLProgramName(GLProgram::SHADER_NAME_POSITION_GRAYSCALE));
效果如下图所示: (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |