gistfile1.cpp

#define GLEW_STATIC
#include <GL/glew.h>
#define OVR_OS_WIN32
#include <OVR_CAPI_GL.h>
#include <SDL.h>
#include <iostream>

#undef main

int _tmain() {
    return 0;
}

int main(int argc, char** argv) {
    SDL_Init(SDL_INIT_VIDEO);
    SDL_Window* window = SDL_CreateWindow("OpenGL", 100, 100, 800, 600, SDL_WINDOW_OPENGL);
    SDL_GLContext context = SDL_GL_CreateContext(window);

    //Initialize GLEW
    glewExperimental = GL_TRUE;
    glewInit();

    // Initialize Oculus context
    ovrResult result = ovr_Initialize(nullptr);
    if (OVR_FAILURE(result)) {
        std::cout << "ERROR: Failed to initialize libOVR" << std::endl;
        SDL_Quit();
        return -1;
    }

    // Connect to the Oculus headset
    ovrSession hmd;
    ovrGraphicsLuid luid;
    result = ovr_Create(&hmd, &luid);
    if (OVR_FAILURE(result)) {
        std::cout << "ERROR: Oculus Rift not detected" << std::endl;
        SDL_Quit();
        return 0;
    }

    ovrHmdDesc desc = ovr_GetHmdDesc(hmd);

    std::cout << "Found " << desc.ProductName << "connected Rift device" << std::endl;

    ovrSizei recommenedTex0Size = ovr_GetFovTextureSize(hmd, ovrEyeType(0), desc.DefaultEyeFov[0], 1.0f);
    ovrSizei bufferSize;
    bufferSize.w = recommenedTex0Size.w * 2;
    bufferSize.h = recommenedTex0Size.h;

    std::cout << "Buffer Size: " << bufferSize.w << ", " << bufferSize.h << std::endl;

    // Generate FBO for oculus
    GLuint oculusFbo = 0;
    glGenFramebuffers(1, &oculusFbo);

    // Create swap texture
    ovrSwapTextureSet* pTextureSet = nullptr;
    if (ovr_CreateSwapTextureSetGL(hmd, GL_SRGB8_ALPHA8, bufferSize.w, bufferSize.h, &pTextureSet) == ovrSuccess) {
        ovrGLTexture* tex = (ovrGLTexture*)&pTextureSet->Textures[0];
        glBindTexture(GL_TEXTURE_2D, tex->OGL.TexId);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    }


    // Create ovrLayerHeader

    ovrEyeRenderDesc eyeRenderDesc[2];
    eyeRenderDesc[0] = ovr_GetRenderDesc(hmd, ovrEye_Left, desc.DefaultEyeFov[0]);
    eyeRenderDesc[1] = ovr_GetRenderDesc(hmd, ovrEye_Right, desc.DefaultEyeFov[1]);

    ovrLayerEyeFov layer;
    memset(&layer, 0, sizeof(ovrLayerEyeFov));
    layer.Header.Type = ovrLayerType_EyeFov;
    layer.Header.Flags = ovrLayerFlag_TextureOriginAtBottomLeft;
    layer.ColorTexture[0] = pTextureSet;
    layer.ColorTexture[1] = nullptr;
    layer.Fov[0] = eyeRenderDesc[0].Fov;
    layer.Fov[1] = eyeRenderDesc[1].Fov;
    layer.Viewport[1].Pos.x = recommenedTex0Size.w;
    layer.Viewport[0].Size = recommenedTex0Size;
    layer.Viewport[1].Size = recommenedTex0Size;

    ovrLayerHeader* layers = &layer.Header;


    SDL_Event windowEvent;
    glEnable(GL_SCISSOR_TEST);
    unsigned int textureIndex = 0;
    while (true) {
        if (SDL_PollEvent(&windowEvent)) {
            if (windowEvent.type == SDL_QUIT) break;
        }

        ovrTrackingState tracking = ovr_GetTrackingState(hmd, 0, true);
        layer.RenderPose[0] = tracking.HeadPose.ThePose;
        layer.RenderPose[1] = tracking.HeadPose.ThePose;
        
        ovrGLTexture* tex = (ovrGLTexture*)(&(pTextureSet->Textures[pTextureSet->CurrentIndex]));
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, oculusFbo);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, tex->OGL.TexId, 0);

        glScissor(0, 0, bufferSize.w / 2, bufferSize.h);
        glClearColor(1.0f, 0, 0, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glScissor(bufferSize.w / 2, 0, bufferSize.w / 2, bufferSize.h);
        glClearColor(0, 0, 1.0f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT);

        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);

        ovr_SubmitFrame(hmd, 0, nullptr, &layers, 1);
        pTextureSet->CurrentIndex = (pTextureSet->CurrentIndex + 1) % pTextureSet->TextureCount;
    }

    SDL_GL_DeleteContext(context);
    SDL_Quit();
    return 0;
}