Any idea why whenever I call Sdl.SDL_Flip( scrnPointer ) I get an exception thrown that says attempting to access protected memory?
The pointer I pass is the one returned by this
vidPtr = Sdl.SDL_SetVideoMode(
width,
height,
depth,
Sdl.SDL_OPENGL | Sdl.SDL_DOUBLEBUF );
the window is created fine so I'm not sure why it doesn't work.
Is there another way of flipping the gl display?
Here's the full class library source,
using System;
using System.Collections.Generic;
using System.Text;
using Tao.Sdl;
using Tao.OpenGl;
using Tao.DevIl;
namespace Vivid2D
{
public class Engine
{
public IntPtr vidPtr;
int dwidth, dheight, ddepth;
public Engine()
{
}
public Engine(int width, int height, int depth)
{
OpenScreen(width, height, depth, false);
}
public Engine(int width, int height, int depth,bool fullscreen)
{
OpenScreen(width, height, depth, fullscreen);
}
~Engine()
{
}
/// <summary>
/// Opens a new window or full screen display
/// and returns true on success.
/// </summary>
/// <param name="width">Width of the display</param>
/// <param name="height">Height of the display</param>
/// <param name="depth">Depth in bits of the display</param>
/// <param name="fullscreen">True to open a full screen, false for a windowed display.</param>
/// <returns>True on success, false if failed.</returns>
public bool OpenScreen(int width, int height, int depth,bool fullscreen)
{
int flags;
if (fullscreen == true)
{
flags = (Sdl.SDL_HWSURFACE | Sdl.SDL_DOUBLEBUF | Sdl.SDL_ANYFORMAT | Sdl.SDL_FULLSCREEN);
}
else
{
flags = (Sdl.SDL_HWSURFACE | Sdl.SDL_DOUBLEBUF | Sdl.SDL_ANYFORMAT);
}
int init = Sdl.SDL_Init(Sdl.SDL_INIT_EVERYTHING);
Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_RED_SIZE, 5);
Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_GREEN_SIZE, 5);
Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_BLUE_SIZE, 5);
Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_DEPTH_SIZE, depth);
Sdl.SDL_GL_SetAttribute(Sdl.SDL_GL_DOUBLEBUFFER, 1);
vidPtr = Sdl.SDL_SetVideoMode(
width,
height,
depth,
Sdl.SDL_OPENGL | Sdl.SDL_DOUBLEBUF );
dwidth = width;
dheight = height;
ddepth = depth;
SetupGL();
SetColor(255, 255, 255);
return true;
}
public void SetupGL()
{
Gl.glViewport(0, 0, dwidth,dheight);
Gl.glMatrixMode(Gl.GL_PROJECTION);
Gl.glLoadIdentity();
Tao.OpenGl.Glu.gluOrtho2D(0, dwidth, 0, dheight);
Gl.glMatrixMode(Gl.GL_MODELVIEW);
Gl.glLoadIdentity();
}
public void ClearScreen()
{
Gl.glClear(Gl.GL_COLOR_BUFFER_BIT);
}
public void FlipScreen()
{
Sdl.SDL_Flip(vidPtr);
}
public void SetColor(float red, float green, float blue)
{
Gl.glColor3f(red / (float)255.0, green / (float)255.0, blue / (float)255.0);
}
public void DrawRect(int x, int y, int width, int height)
{
Gl.glBegin(Gl.GL_QUADS);
Gl.glVertex2i(x, y);
Gl.glVertex2i(x + width, y);
Gl.glVertex2i(x + width, y + height);
Gl.glVertex2i(x, y + height);
Gl.glEnd();
}
}
}
And the example code that uses the above class lib.
using System;
using System.Collections.Generic;
using System.Text;
using Vivid2D;
using Tao.Sdl;
namespace Vivid2D_Example1
{
class Program
{
static void Main(string[] args)
{
Engine meng = new Engine();
meng.OpenScreen(640, 480, 16, false);
while (true)
{
meng.ClearScreen();
meng.DrawRect(20, 20, 200, 200);
meng.FlipScreen();
}
}
}
}
