FGFS-4.1/OpenSceneGraph
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Added usage of image copy and modification.

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This commit is contained in:
Robert Osfield 2005-11-01 17:07:55 +00:00
parent e23176c3b6
commit 12bd1f7d4b
1 changed files with 106 additions and 11 deletions
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117
examples/osgprerender/osgprerender.cpp
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@ -4,6 +4,7 @@
#include <osg/Notify>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/TextureRectangle>
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
@ -107,7 +108,52 @@ class MyGeometryCallback :
};
osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsigned tex_height, osg::CameraNode::RenderTargetImplementation renderImplementation)
struct MyCameraPostDrawCallback : public osg::CameraNode::DrawCallback
{
MyCameraPostDrawCallback(osg::Image* image):
_image(image)
{
}
virtual void operator () (const osg::CameraNode& /*camera*/) const
{
if (_image && _image->getPixelFormat()==GL_RGBA && _image->getDataType()==GL_UNSIGNED_BYTE)
{
// we'll pick out the center 1/2 of the whole image,
int column_start = _image->s()/4;
int column_end = 3*column_start;
int row_start = _image->t()/4;
int row_end = 3*row_start;
// and then invert these pixels
for(int r=row_start; r<row_end; ++r)
{
unsigned char* data = _image->data(column_start, r);
for(int c=column_start; c<column_end; ++c)
{
(*data) = 255; ++data;
(*data) = (*data); ++data;
(*data) = (*data); ++data;
(*data) = 255; ++data;
}
}
// dirty the image (increments the modified count) so that any textures
// using the image can be informed that they need to update.
_image->dirty();
}
}
osg::Image* _image;
};
osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsigned tex_height, osg::CameraNode::RenderTargetImplementation renderImplementation, bool useImage, bool useTextureRectangle)
{
if (!subgraph) return 0;
@ -115,11 +161,27 @@ osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsi
osg::Group* parent = new osg::Group;
// texture to render to and to use for rendering of flag.
osg::Texture2D* texture = new osg::Texture2D;
texture->setTextureSize(tex_width, tex_height);
texture->setInternalFormat(GL_RGBA);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
osg::Texture* texture = 0;
if (useTextureRectangle)
{
osg::TextureRectangle* textureRect = new osg::TextureRectangle;
textureRect->setTextureSize(tex_width, tex_height);
textureRect->setInternalFormat(GL_RGBA);
textureRect->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
textureRect->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
texture = textureRect;
}
else
{
osg::Texture2D* texture2D = new osg::Texture2D;
texture2D->setTextureSize(tex_width, tex_height);
texture2D->setInternalFormat(GL_RGBA);
texture2D->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture2D->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
texture = texture2D;
}
// first create the geometry of the flag of which to view.
{
@ -142,9 +204,11 @@ osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsi
osg::Vec3 dv = xAxis*(width/((float)(noSteps-1)));
osg::Vec2Array* texcoords = new osg::Vec2Array;
// note, when we use TextureRectangle we have to scale the tex coords up to compensate.
osg::Vec2 bottom_texcoord(0.0f,0.0f);
osg::Vec2 top_texcoord(0.0f,1.0f);
osg::Vec2 dv_texcoord(1.0f/(float)(noSteps-1),0.0f);
osg::Vec2 top_texcoord(0.0f, useTextureRectangle ? tex_height : 1.0f);
osg::Vec2 dv_texcoord((useTextureRectangle ? tex_width : 1.0f)/(float)(noSteps-1),0.0f);
for(int i=0;i<noSteps;++i)
{
@ -231,8 +295,33 @@ osg::Node* createPreRenderSubGraph(osg::Node* subgraph, unsigned tex_width, unsi
// tell the camera to use OpenGL frame buffer object where supported.
camera->setRenderTargetImplementation(renderImplementation);
// attach the texture and use it as the color buffer.
camera->attach(osg::CameraNode::COLOR_BUFFER, texture);
if (useImage)
{
osg::Image* image = new osg::Image;
image->allocateImage(tex_width, tex_height, 1, GL_RGBA, GL_UNSIGNED_BYTE);
// attach the image so its copied on each frame.
camera->attach(osg::CameraNode::COLOR_BUFFER, image);
camera->setPostDrawCallback(new MyCameraPostDrawCallback(image));
// Rather than attach the texture directly to illustrate the texture's ability to
// detect an image update and to subload the image onto the texture. You needn't
// do this when using an Image for copying to, as a seperate camera->attach(..)
// would suffice as well, but we'll do it the long way round here just for demonstation
// purposes (long way round meaning we'll need to copy image to main memory, then
// copy it back to the graphics card to the texture in one frame).
// The long way round allows us to mannually modify the copied image via the callback
// and then let this modified image by reloaded back.
texture->setImage(0, image);
}
else
{
// attach the texture and use it as the color buffer.
camera->attach(osg::CameraNode::COLOR_BUFFER, texture);
}
// add subgraph to render
camera->addChild(subgraph);
@ -289,6 +378,12 @@ int main( int argc, char **argv )
while (arguments.read("--fb")) { renderImplementation = osg::CameraNode::FRAME_BUFFER; }
while (arguments.read("--window")) { renderImplementation = osg::CameraNode::SEPERATE_WINDOW; }
bool useImage = false;
while (arguments.read("--image")) { useImage = true; }
bool useTextureRectangle = false;
while (arguments.read("--texture-rectangle")) { useTextureRectangle = true; }
// any option left unread are converted into errors to write out later.
arguments.reportRemainingOptionsAsUnrecognized();
@ -322,7 +417,7 @@ int main( int argc, char **argv )
loadedModelTransform->setUpdateCallback(nc);
osg::Group* rootNode = new osg::Group();
rootNode->addChild(createPreRenderSubGraph(loadedModelTransform,tex_width,tex_height, renderImplementation));
rootNode->addChild(createPreRenderSubGraph(loadedModelTransform,tex_width,tex_height, renderImplementation, useImage, useTextureRectangle));
// add model to the viewer.