Support rendering to a given FBO instead of to the screen.

[movit] / effect_chain.cpp

diff --git a/effect_chain.cpp b/effect_chain.cpp
index b5d136b275dc7d58c9791f0b58f25768afad3bb5..c3776e85f605568a51ca61e221e826b87dbc2231 100644 (file)
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -961,13 +961,21 @@ void EffectChain::finalize()
        finalized = true;
 }
 
-void EffectChain::render_to_screen()
+void EffectChain::render_to_fbo(GLuint fbo, unsigned width, unsigned height)
 {
        assert(finalized);
 
        // Save original viewport.
-       GLint viewport[4];
-       glGetIntegerv(GL_VIEWPORT, viewport);
+       GLuint x = 0, y = 0;
+
+       if (width == 0 && height == 0) {
+               GLint viewport[4];
+               glGetIntegerv(GL_VIEWPORT, viewport);
+               x = viewport[0];
+               y = viewport[1];
+               width = viewport[2];
+               height = viewport[3];
+       }
 
        // Basic state.
        glDisable(GL_BLEND);
@@ -1045,10 +1053,10 @@ void EffectChain::render_to_screen()
 
                // And now the output.
                if (phase == phases.size() - 1) {
-                       // Last phase goes directly to the screen.
-                       glBindFramebuffer(GL_FRAMEBUFFER, 0);
+                       // Last phase goes to the output the user specified.
+                       glBindFramebuffer(GL_FRAMEBUFFER, fbo);
                        check_error();
-                       glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
+                       glViewport(x, y, width, height);
                } else {
                        Node *output_node = phases[phase]->effects.back();
                        glFramebufferTexture2D(