BGE: Various render improvements.

bge.logic.setRender(flag) to enable/disable render.
    The render pass is enabled by default but it can be disabled with
    bge.logic.setRender(False).
    Once disabled, the render pass is skipped and a new logic frame starts
    immediately. Note that VSync no longer limits the fps when render is off
    but the 'Use Frame Rate' option in the Render Properties still does.
    To run as many frames as possible, untick the option
    This function is useful when you don't need the default render, e.g.
    when doing offscreen render to an alternate device than the monitor.
    Note that without VSync, you must limit the frame rate by other means.

fbo = bge.render.offScreenCreate(width,height,[,samples=0][,target=bge.render.RAS_OFS_RENDER_BUFFER])
    Use this method to create an offscreen buffer of given size, with given MSAA
    samples and targetting either a render buffer (bge.render.RAS_OFS_RENDER_BUFFER)
    or a texture (bge.render.RAS_OFS_RENDER_TEXTURE). Use the former if you want to
    retrieve the frame buffer on the host and the latter if you want to pass the render
    to another context (texture are proper OGL object, render buffers aren't)
    The object created by this function can only be used as a parameter of the
    bge.texture.ImageRender() constructor to send the the render to the FBO rather
    than to the frame buffer. This is best suited when you want to create a render
    of specific size, or if you need an image with an alpha channel.

bge.texture.<imagetype>.refresh(buffer=None, format="RGBA", ts=-1.0)
    Without arg, the refresh method of the image objects is pretty much a no-op, it
    simply invalidates the image so that on next texture refresh, the image will
    be recalculated.
    It is now possible to pass an optional buffer object to transfer the image (and
    recalculate it if it was invalid) to an external object. The object must implement
    the 'buffer protocol'. The image will be transfered as "RGBA" or "BGRA" pixels
    depending on format argument (only those 2 formats are supported) and ts is an
    optional timestamp in the image depends on it (e.g. VideoFFmpeg playing a video file).
    With this function you don't need anymore to link the image object to a Texture
    object to use: the image object is self-sufficient.

bge.texture.ImageRender(scene, camera, fbo=None)
    Render to buffer is possible by passing a FBO object (see offScreenCreate).

bge.texture.ImageRender.render()
    Allows asynchronous render: call this method to render the scene but without
    extracting the pixels yet. The function returns as soon as the render commands
    have been send to the GPU. The render will proceed asynchronously in the GPU
    while the host can perform other tasks.
    To complete the render, you can either call refresh() directly of refresh the texture
    to which this object is the source. Asynchronous render is useful to achieve optimal
    performance: call render() on frame N and refresh() on frame N+1 to give as much as
    time as possible to the GPU to render the frame while the game engine can perform other tasks.

Support negative scale on camera.
    Camera scale was previously ignored in the BGE.
    It is now injected in the modelview matrix as a vertical or horizontal flip
    of the scene (respectively if scaleY<0 and scaleX<0).
    Note that the actual value of the scale is not used, only the sign.
    This allows to flip the image produced by ImageRender() without any performance
    degradation: the flip is integrated in the render itself.

Optimized image transfer from ImageRender to buffer.
    Previously, images that were transferred to the host were always going through
    buffers in VideoTexture. It is now possible to transfer ImageRender
    images to external buffer without intermediate copy (i.e. directly from OGL to buffer)
    if the attributes of the ImageRender objects are set as follow:
       flip=False, alpha=True, scale=False, depth=False, zbuff=False.
       (if you need to flip the image, use camera negative scale)

1 files changed, 82 insertions, 17 deletions

diff --git a/source/gameengine/VideoTexture/ImageViewport.cpp b/source/gameengine/VideoTexture/ImageViewport.cpp
index 820a019832e..8852c190053 100644
--- a/source/gameengine/VideoTexture/ImageViewport.cpp
+++ b/source/gameengine/VideoTexture/ImageViewport.cpp
@@ -45,14 +45,22 @@
 
 
 // constructor
-ImageViewport::ImageViewport (void) : m_alpha(false), m_texInit(false)
+ImageViewport::ImageViewport (PyRASOffScreen *offscreen) : m_alpha(false), m_texInit(false)
 {
 	// get viewport rectangle
-	RAS_Rect rect = KX_GetActiveEngine()->GetCanvas()->GetWindowArea();
-	m_viewport[0] = rect.GetLeft();
-	m_viewport[1] = rect.GetBottom();
-	m_viewport[2] = rect.GetWidth();
-	m_viewport[3] = rect.GetHeight();
+	if (offscreen) {
+		m_viewport[0] = 0;
+		m_viewport[1] = 0;
+		m_viewport[2] = offscreen->ofs->GetWidth();
+		m_viewport[3] = offscreen->ofs->GetHeight();
+	}
+	else {
+		RAS_Rect rect = KX_GetActiveEngine()->GetCanvas()->GetWindowArea();
+		m_viewport[0] = rect.GetLeft();
+		m_viewport[1] = rect.GetBottom();
+		m_viewport[2] = rect.GetWidth();
+		m_viewport[3] = rect.GetHeight();
+	}
 	
 	//glGetIntegerv(GL_VIEWPORT, m_viewport);
 	// create buffer for viewport image
@@ -60,7 +68,7 @@ ImageViewport::ImageViewport (void) : m_alpha(false), m_texInit(false)
 	//          float (1 float = 4 bytes per pixel)
 	m_viewportImage = new BYTE [4 * getViewportSize()[0] * getViewportSize()[1]];
 	// set attributes
-	setWhole(false);
+	setWhole((offscreen) ? true : false);
 }
 
 // destructor
@@ -126,25 +134,26 @@ void ImageViewport::setPosition (GLint pos[2])
 
 
 // capture image from viewport
-void ImageViewport::calcImage (unsigned int texId, double ts)
+void ImageViewport::calcViewport (unsigned int texId, double ts, unsigned int format)
 {
 	// if scale was changed
 	if (m_scaleChange)
 		// reset image
 		init(m_capSize[0], m_capSize[1]);
 	// if texture wasn't initialized
-	if (!m_texInit) {
+	if (!m_texInit && texId != 0) {
 		// initialize it
 		loadTexture(texId, m_image, m_size);
 		m_texInit = true;
 	}
 	// if texture can be directly created
-	if (texId != 0 && m_pyfilter == NULL && m_capSize[0] == calcSize(m_capSize[0])
-	    && m_capSize[1] == calcSize(m_capSize[1]) && !m_flip && !m_zbuff && !m_depth)
+	if (texId != 0 && m_pyfilter == NULL && m_size[0] == m_capSize[0] &&
+	    m_size[1] == m_capSize[1] && !m_flip && !m_zbuff && !m_depth)
 	{
 		// just copy current viewport to texture
 		glBindTexture(GL_TEXTURE_2D, texId);
 		glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1]);
+		glBindTexture(GL_TEXTURE_2D, 0);
 		// image is not available
 		m_avail = false;
 	}
@@ -176,11 +185,33 @@ void ImageViewport::calcImage (unsigned int texId, double ts)
 
 				// get frame buffer data
 				if (m_alpha) {
-					glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], GL_RGBA,
-					        GL_UNSIGNED_BYTE, m_viewportImage);
-					// filter loaded data
-					FilterRGBA32 filt;
-					filterImage(filt, m_viewportImage, m_capSize);
+					// as we are reading the pixel in the native format, we can read directly in the image buffer
+					// if we are sure that no processing is needed on the image
+					if (m_size[0] == m_capSize[0] &&
+					    m_size[1] == m_capSize[1] &&
+					    !m_flip &&
+					    !m_pyfilter)
+					{
+						glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], format,
+						             GL_UNSIGNED_BYTE, m_image);
+						m_avail = true;
+					}
+					else if (!m_pyfilter) {
+						glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], format,
+						             GL_UNSIGNED_BYTE, m_viewportImage);
+						FilterRGBA32 filt;
+						filterImage(filt, m_viewportImage, m_capSize);
+					}
+					else {
+						glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], GL_RGBA,
+						             GL_UNSIGNED_BYTE, m_viewportImage);
+						FilterRGBA32 filt;
+						filterImage(filt, m_viewportImage, m_capSize);
+						if (format == GL_BGRA) {
+							// in place byte swapping
+							swapImageBR();
+						}
+					}
 				}
 				else {
 					glReadPixels(m_upLeft[0], m_upLeft[1], (GLsizei)m_capSize[0], (GLsizei)m_capSize[1], GL_RGB,
@@ -188,12 +219,46 @@ void ImageViewport::calcImage (unsigned int texId, double ts)
 					// filter loaded data
 					FilterRGB24 filt;
 					filterImage(filt, m_viewportImage, m_capSize);
+					if (format == GL_BGRA) {
+						// in place byte swapping
+						swapImageBR();
+					}
 				}
 			}
 		}
 	}
 }
 
+bool ImageViewport::loadImage(unsigned int *buffer, unsigned int size, unsigned int format, double ts)
+{
+	unsigned int *tmp_image;
+	bool ret;
+
+	// if scale was changed
+	if (m_scaleChange) {
+		// reset image
+		init(m_capSize[0], m_capSize[1]);
+	}
+
+	// size must be identical
+	if (size < getBuffSize())
+		return false;
+
+	if (m_avail) {
+		// just copy
+		return ImageBase::loadImage(buffer, size, format, ts);
+	}
+	else {
+		tmp_image = m_image;
+		m_image = buffer;
+		calcViewport(0, ts, format);
+		ret = m_avail;
+		m_image = tmp_image;
+		// since the image was not loaded to our buffer, it's not valid
+		m_avail = false;
+	}
+	return ret;
+}
 
 
 // cast Image pointer to ImageViewport
@@ -336,7 +401,7 @@ int ImageViewport_setCaptureSize(PyImage *self, PyObject *value, void *closure)
 // methods structure
 static PyMethodDef imageViewportMethods[] =
 { // methods from ImageBase class
-	{"refresh", (PyCFunction)Image_refresh, METH_NOARGS, "Refresh image - invalidate its current content"},
+	{"refresh", (PyCFunction)Image_refresh, METH_VARARGS, "Refresh image - invalidate its current content"},
 	{NULL}
 };
 // attributes structure