我有一个 sdl/opengl 游戏,我正在为好玩而工作。平均而言,我得到了不错的 fps,但运动真的很不稳定,因为 SDL_GL_SwapBuffers() 会随机花费很长的时间来处理。加载纹理并将其写入缓冲区有时会花费超过 100 毫秒!我剪掉了很多代码来尝试找出是否是我做错了,但我运气不佳。当我运行这个简单的程序时,它有时仍会阻塞长达 70 毫秒。
主要的:
// Don't forget to link to opengl32, glu32, SDL_image.lib
// includes
#include <stdio.h>
// SDL
#include <cstdlib>
#include <SDL/SDL.h>
// Video
#include "videoengine.h"
int main(int argc, char *argv[])
{
// begin SDL
if ( SDL_Init(SDL_INIT_VIDEO) != 0 )
{
printf("Unable to initialize SDL: %s\n", SDL_GetError());
}
// begin video class
VideoEngine videoEngine;
// BEGIN MAIN LOOP
bool done = false;
while (!done)
{
int loopStart = SDL_GetTicks();
printf("STARTING SWAP BUFFER : %d\n", SDL_GetTicks() - loopStart);
SDL_GL_SwapBuffers();
int total = SDL_GetTicks() - loopStart;
if (total > 6)
printf("END LOOP : %d ------------------------------------------------------------>\n", total);
else
printf("END LOOP : %d\n", total);
}
// END MAIN LOOP
return 0;
}
我的“VideoEngine”构造函数:
VideoEngine::VideoEngine()
{
UNIT = 16;
SCREEN_X = 320;
SCREEN_Y = 240;
SCALE = 1;
// Begin Initalization
SDL_Surface *screen;
SDL_GL_SetAttribute( SDL_GL_DOUBLEBUFFER, 1 ); // [!] SDL_GL_SetAttributes must be done BEFORE SDL_SetVideoMode
screen = SDL_SetVideoMode( SCALE*SCREEN_X, SCALE*SCREEN_Y, 16, SDL_OPENGL ); // Set screen to the window with opengl
if ( !screen ) // make sure the window was created
{
printf("Unable to set video mode: %s\n", SDL_GetError());
}
// set opengl state
opengl_init();
// End Initalization
}
void VideoEngine::opengl_init()
{
// Set the OpenGL state after creating the context with SDL_SetVideoMode
//glClearColor( 0, 0, 0, 0 ); // sets screen buffer to black
//glClearDepth(1.0f); // Tells OpenGL what value to reset the depth buffer when it is cleared
glViewport( 0, 0, SCALE*SCREEN_X, SCALE*SCREEN_Y ); // sets the viewport to the default resolution (SCREEN_X x SCREEN_Y) multiplied by SCALE. (x,y,w,h)
glMatrixMode( GL_PROJECTION ); // Applies subsequent matrix operations to the projection matrix stack.
glLoadIdentity(); // Replaces the current matrix with the identity matrix
glOrtho( 0, SCALE*SCREEN_X, SCALE*SCREEN_Y, 0, -1, 1 ); //describes a transformation that produces a parallel projection
glMatrixMode( GL_MODELVIEW ); // Applies subsequent matrix operations to the projection matrix stack.
glEnable(GL_TEXTURE_2D); // Need this to display a texture
glLoadIdentity(); // Replaces the current matrix with the identity matrix
glEnable(GL_BLEND); // Enable blending for transparency
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // Specifies pixel arithmetic
//glDisable( GL_LIGHTING ); // Disable lighting
//glDisable( GL_DITHER ); // Disable dithering
//glDisable( GL_DEPTH_TEST ); // Disable depth testing
//Check for error
GLenum error = glGetError();
if( error != GL_NO_ERROR )
{
printf( "Error initializing OpenGL! %s\n", gluErrorString( error ) );
}
return;
}
我开始认为我可能有硬件问题?不过,我从来没有在游戏中遇到过这个问题。