Texture.hpp

/*
 * A VCOS shared memory render target with one RGBA buffer (read-write)
 * VCOS only support POT textures, so only a part will be used
 */
class VCSMRenderTarget : public RenderTarget
{
    public:
    int bufferWidth, bufferHeight;
    VCSMRenderTarget (int Width, int Height, EGLDisplay Display);
    ~VCSMRenderTarget (void);
    void setTarget (void) override;
    void setSource (ShaderProgram *shader, int slot) override;
    uint8_t* lock(void);
    void unlock(void);

    private:
    GLuint TEX_ID;
    struct egl_image_brcm_vcsm_info VCSM;
    EGLImageKHR eglImg;
    uint8_t *vcsmBuffer;
    EGLDisplay eglDisplay;
};


static int nextPOT (int NPOT)
{
    NPOT--;
    NPOT |= NPOT >> 1;
    NPOT |= NPOT >> 2;
    NPOT |= NPOT >> 4;
    NPOT |= NPOT >> 8;
    NPOT++;
    return std::max(64, NPOT);
}

VCSMRenderTarget::VCSMRenderTarget (int Width, int Height, EGLDisplay Display)
{
    width = Width;
    height = Height;
    bufferWidth = nextPOT(width);
    bufferHeight = nextPOT(height);
    std::cout << "Texture Size " << width << "x" << height << std::endl;
    std::cout << "Buffer Size " << bufferWidth << "x" << bufferHeight << std::endl;
    eglDisplay = Display;
    // Framebuffer
    glGenFramebuffers(1, &FBO_ID);
    glBindFramebuffer(GL_FRAMEBUFFER, FBO_ID);
    // Create texture handle
    glGenTextures(1, &TEX_ID);
    glBindTexture(GL_TEXTURE_2D, TEX_ID);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); // GL_LINEAR / GL_NEAREST
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); // GL_LINEAR / GL_NEAREST
    // Allocate VCOS Shared Memory and assign to texture
    VCSM.width = bufferWidth;
    VCSM.height = bufferHeight;
    eglImg = eglCreateImageKHR(eglDisplay, EGL_NO_CONTEXT, EGL_IMAGE_BRCM_VCSM, &VCSM, NULL);
    CHECK_GL();
    glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, eglImg);
    CHECK_GL();
    // Bind texture to framebuffer
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, TEX_ID, 0);
    if (eglImg == EGL_NO_IMAGE_KHR || VCSM.vcsm_handle == 0)
    {
        std::cout << VCOS_FUNCTION << ": Failed to create EGL VCSM image\n";
        return;
    }
    CHECK_GL();
    // Check
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
    {
        std::cout << "Error: Framebuffer not complete: " << glCheckFramebufferStatus(GL_FRAMEBUFFER) << "\n";
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}
VCSMRenderTarget::~VCSMRenderTarget (void)
{
    glDeleteTextures(1, &TEX_ID);
    glDeleteFramebuffers(1, &FBO_ID);
    eglDestroyImageKHR(eglDisplay, eglImg);
}
void VCSMRenderTarget::setTarget (void)
{
    glViewport(0, 0, width, height); // Important: only the actual texture, not full buffer
    glBindFramebuffer(GL_FRAMEBUFFER, FBO_ID);
}
void VCSMRenderTarget::setSource (ShaderProgram *shader, int slot)
{
    glUniform1i(shader->uWidthAdr, bufferWidth);
    glUniform1i(shader->uHeightAdr, bufferHeight);
    glUniform1i(shader->uImageAdr, slot);
    glActiveTexture(GL_TEXTURE0 + slot);
    glBindTexture(GL_TEXTURE_2D, TEX_ID);
}
uint8_t* VCSMRenderTarget::lock (void)
{
    VCSM_CACHE_TYPE_T cacheType;
    vcsmBuffer = (uint8_t*)vcsm_lock_cache(VCSM.vcsm_handle, VCSM_CACHE_TYPE_HOST, &cacheType);
    if (!vcsmBuffer) std::cout << "Failed to lock VCSM buffer!\n";
    return vcsmBuffer;
}
void VCSMRenderTarget::unlock (void)
{
    vcsm_unlock_ptr(vcsmBuffer);
}