added WriteTexture function to write rendered pixel into a texture

opengl-test-two/main.cpp

@@ -148,6 +148,27 @@ GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path
 	return ProgramID;
 }
 
+GLuint WriteTexture(int textw, int texth){
+    // The framebuffer, which regroups 0, 1, or more textures, and 0 or 1 depth buffer.
+    GLuint FramebufferName = 0;
+    glGenFramebuffers(1, &FramebufferName);
+    glBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);
+
+    // The texture we're going to render to
+    GLuint renderedTexture;
+    glGenTextures(1, &renderedTexture);
+
+    // "Bind" the newly created texture : all future texture functions will modify this texture
+    glBindTexture(GL_TEXTURE_2D, renderedTexture);
+
+    // Give an empty image to OpenGL ( the last "0" )
+    glTexImage2D(GL_TEXTURE_2D, 0,GL_RGB, textw, texth, 0,GL_RGB, GL_UNSIGNED_BYTE, 0);
+
+    // Poor filtering. Needed !
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+
+}
 
 
 int main(int argc, char* args[]) {