Fix another set of test breakages on NVIDIA.

[movit] / effect_chain.h

diff --git a/effect_chain.h b/effect_chain.h
index dc5e3c4aeb96ca0c585ee63d3c31350c2d6e60c8..716a970a3ab59748e99d94da43b2a9239fdca871 100644 (file)
--- a/effect_chain.h
+++ b/effect_chain.h
@@ -389,6 +389,27 @@ public:
        // the current viewport.
        void render_to_fbo(GLuint fbo, unsigned width, unsigned height);
 
+       // Render the effect chain to the given set of textures. This is equivalent
+       // to render_to_fbo() with a freshly created FBO bound to the given textures,
+       // except that it is more efficient if the last phase contains a compute shader.
+       // Thus, prefer this to render_to_fbo() where possible.
+       //
+       // Only one destination texture is supported. This restriction will be lifted
+       // in the future.
+       //
+       // All destination textures must be exactly of size <width> x <height>,
+       // and must either come from the same ResourcePool the effect uses, or outlive
+       // the EffectChain (otherwise, we could be allocating FBOs that end up being
+       // stale). Textures must also have valid state; in particular, they must either
+       // be mipmap complete or have a non-mipmapped minification mode.
+       //
+       // width and height can not be zero.
+       struct DestinationTexture {
+               GLuint texnum;
+               GLenum format;
+       };
+       void render_to_texture(const std::vector<DestinationTexture> &destinations, unsigned width, unsigned height);
+
        Effect *last_added_effect() {
                if (nodes.empty()) {
                        return nullptr;
@@ -457,9 +478,19 @@ private:
        // as the last effect. Also pushes all phases in order onto <phases>.
        Phase *construct_phase(Node *output, std::map<Node *, Phase *> *completed_effects);
 
+       // Do the actual rendering of the chain. If <dest_fbo> is not (GLuint)-1,
+       // renders to that FBO. If <destinations> is non-empty, render to that set
+       // of textures (last phase, save for the dummy phase, must be a compute shader),
+       // with x/y ignored. Having both set is an error.
+       void render(GLuint dest_fbo, const std::vector<DestinationTexture> &destinations,
+                   unsigned x, unsigned y, unsigned width, unsigned height);
+
        // Execute one phase, ie. set up all inputs, effects and outputs, and render the quad.
-       void execute_phase(Phase *phase, bool last_phase,
-                          std::map<Phase *, GLuint> *output_textures,
+       // If <destinations> is empty, uses whatever output is current (and the phase must not be
+       // a compute shader).
+       void execute_phase(Phase *phase,
+                          const std::map<Phase *, GLuint> &output_textures,
+                          const std::vector<DestinationTexture> &destinations,
                           std::set<Phase *> *generated_mipmaps);
 
        // Set up uniforms for one phase. The program must already be bound.
@@ -539,6 +570,12 @@ private:
        bool finalized;
        GLuint vbo;  // Contains vertex and texture coordinate data.
 
+       // Whether the last effect (which will then be in a phase all by itself)
+       // is a dummy effect that is only added because the last phase uses a compute
+       // shader, which cannot output directly to the backbuffer. This means that
+       // the phase can be skipped if we are _not_ rendering to the backbuffer.
+       bool has_dummy_effect = false;
+
        ResourcePool *resource_pool;
        bool owns_resource_pool;