Skia OpenGL Texture Helloworld

这年头神马都要炫，这不，我就开始研究Skia了。先上一个Skia画在opengl texture上面的圆角矩形。

以下代码：

#include <SkDevice.h> #include <SkDraw.h> #include <SkRect.h> #include <memory> #include <GL/gl.h> #include <GL/glut.h> #include <stdio.h> #include <stdlib.h> static void idle(void ); static void resize(int x , int y); static void mouseKey(int button, int state, int x , int y); static void keyFunc(unsigned char c,int x,int y); static void mouseMove(int x , int y); static void draw(void); static SkBitmap createBitmap(int x,int y) { SkBitmap bitmap; bitmap.setConfig(SkBitmap::kARGB_8888_Config, x, y); bitmap.setIsOpaque(true); bitmap.allocPixels(); std::auto_ptr<SkCanvas> psCanvas(new SkCanvas(bitmap)); SkPaint p; p.setAntiAlias(true); p.setStyle(SkPaint::kStroke_Style); p.setStrokeWidth(4); p.setColor(SkColorSetARGBInline(255,244,203,244)); psCanvas->clear(SkColorSetARGBInline(255,0,0,0)); psCanvas->drawRoundRect(SkRect::MakeXYWH(100,100,200,200),10,15,p); return bitmap; } static void generateR8G8B8FromSkBitmap(SkBitmap & aBitmap,void *& aOutBuf,size_t & aOutBufSize) { aOutBufSize = aBitmap.width() * aBitmap.height() * 3; aOutBuf = malloc(aOutBufSize); SkAutoLockPixels sAutoLock(aBitmap); uint32_t * sAddress = aBitmap.getAddr32(0,0); char * sWriter = (char * )aOutBuf; const uint32_t * sReader = sAddress; for(int y = 0 ; y < aBitmap.height() ; ++y) { for(int x = 0 ; x < aBitmap.width() ; ++ x,++sReader) { uint32_t sPixel = *sReader; const char * sPixelReader = (const char * )&sPixel; // R *sWriter = *sPixelReader; ++sWriter; ++sPixelReader; // G *sWriter = *sPixelReader; ++sWriter; ++sPixelReader; // B *sWriter = *sPixelReader; ++sWriter; ++sPixelReader; } } } GLuint getTextureFromBitmap(SkBitmap & aBitmap) { GLuint sTexture; GLenum sError; glGenTextures(1,&sTexture); glBindTexture(GL_TEXTURE_2D,sTexture); void * sBitmapContent; size_t sBitmapSize; generateR8G8B8FromSkBitmap(aBitmap,sBitmapContent,sBitmapSize); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR); // Linear Filtering sError = glGetError(); printf("GL_TEXTURE_MIN_FILTER error code is %d/n",sError); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR); // Linear Filtering sError = glGetError(); printf("GL_TEXTURE_MAG_FILTER error code is %d/n",sError); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP); sError = glGetError(); printf("GL_TEXTURE_WRAP_S error code is %d/n",sError); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP); sError = glGetError(); printf("GL_TEXTURE_WRAP_T error code is %d/n",sError); glTexImage2D(GL_TEXTURE_2D,0,GL_RGB,aBitmap.width(),aBitmap.height(),0,GL_RGB,GL_UNSIGNED_BYTE,sBitmapContent); sError = glGetError(); printf("glTexImage2D error code is %d/n",sError); free(sBitmapContent); return sTexture; } int main(int argc,char ** argv) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH); glutInitWindowSize(800,600); //glutInitContextFlags(GLUT_FORWARD_COMPATIBLE); glutCreateWindow("test wglUseFontOutlines"); glutDisplayFunc(draw); glutIdleFunc(idle); glutReshapeFunc(resize); glutMouseFunc(mouseKey); glutMotionFunc(mouseMove); glutKeyboardFunc(keyFunc); glViewport(0,0,800,600); glClearColor(0.0f, 0.0f, 0.0f, 0.5f); glutMainLoop(); return 0; } void idle() { } void resize(int x , int y) { glViewport(0,0,x,y); } void mouseKey(int button, int state, int x , int y) { } void keyFunc(unsigned char c,int x,int y) { } void mouseMove(int x , int y) { } void draw() { glClear(GL_COLOR_BUFFER_BIT); // Set up transformation to draw the string glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(1,1,1,1,1,1); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0f, 0.0f, 0.0f) ; // glPolygonMode(GL_FRONT,GL_LINE); glCullFace(GL_BACK); glEnable(GL_CULL_FACE); glEnable(GL_TEXTURE_2D); GLint sViewportParam[4]; glGetIntegerv(GL_VIEWPORT,sViewportParam); SkBitmap sBitmap = createBitmap(sViewportParam[2],sViewportParam[3]); GLuint sTexture = getTextureFromBitmap(sBitmap); glBindTexture(GL_TEXTURE_2D,sTexture); glBegin(GL_TRIANGLE_STRIP); // glColor3f(1.0f,0.0,0.0); glTexCoord2f(0.0f,1.0f); glVertex2f(-1.0f,1.0f); // glColor3f(0.0,1.0f,0.0f); glTexCoord2f(0.0f,0.0f); glVertex2f(-1.0f,-1.0f); // glColor3f(0.0,1.0f,1.0f); glTexCoord2f(1.0f,1.0f); glVertex2f(1.0f,1.0f); // glColor3f(0.0,0.0,1.0f); glTexCoord2f(1.0f,0.0f);  

 

接着上图：