namespace {
-// An effect that does nothing.
-class IdentityEffect : public Effect {
+// An effect whose only purpose is to sit in a phase on its own and take the
+// texture output from a compute shader and display it to the normal backbuffer
+// (or any FBO). That phase can be skipped when rendering using render_to_textures().
+class ComputeShaderOutputDisplayEffect : public Effect {
public:
- IdentityEffect() {}
- virtual string effect_type_id() const { return "IdentityEffect"; }
- string output_fragment_shader() { return read_file("identity.frag"); }
+ ComputeShaderOutputDisplayEffect() {}
+ string effect_type_id() const override { return "ComputeShaderOutputDisplayEffect"; }
+ string output_fragment_shader() override { return read_file("identity.frag"); }
+ bool needs_texture_bounce() const override { return true; }
};
} // namespace
node->output_alpha_type = ALPHA_INVALID;
node->needs_mipmaps = false;
node->one_to_one_sampling = false;
+ node->strong_one_to_one_sampling = false;
nodes.push_back(node);
node_map[effect] = node;
Node *node = phase->effects[i];
const string effect_id = phase->effect_ids[node];
if (node->incoming_links.size() == 1) {
- frag_shader += string("#define INPUT ") + phase->effect_ids[node->incoming_links[0]] + "\n";
+ Node *input = node->incoming_links[0];
+ if (i != 0 && input->effect->is_compute_shader()) {
+ // First effect after the compute shader reads the value
+ // that cs_output() wrote to a global variable.
+ frag_shader += string("#define INPUT(tc) CS_OUTPUT_VAL\n");
+ } else {
+ frag_shader += string("#define INPUT ") + phase->effect_ids[input] + "\n";
+ }
} else {
for (unsigned j = 0; j < node->incoming_links.size(); ++j) {
+ assert(!node->incoming_links[j]->effect->is_compute_shader());
char buf[256];
sprintf(buf, "#define INPUT%d %s\n", j + 1, phase->effect_ids[node->incoming_links[j]].c_str());
frag_shader += buf;
}
frag_shader += "\n";
}
- frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
+ if (phase->is_compute_shader) {
+ frag_shader += string("#define INPUT ") + phase->effect_ids[phase->compute_shader_node] + "\n";
+ if (phase->compute_shader_node == phase->effects.back()) {
+ // No postprocessing.
+ frag_shader += "#define CS_POSTPROC(tc) CS_OUTPUT_VAL\n";
+ } else {
+ frag_shader += string("#define CS_POSTPROC ") + phase->effect_ids[phase->effects.back()] + "\n";
+ }
+ } else {
+ frag_shader += string("#define INPUT ") + phase->effect_ids[phase->effects.back()] + "\n";
+ }
// If we're the last phase, add the right #defines for Y'CbCr multi-output as needed.
vector<string> frag_shader_outputs; // In order.
}
if (phase->is_compute_shader) {
- frag_shader.append(read_file("footer.compute"));
- phase->output_node->effect->register_uniform_vec2("inv_output_size", (float *)&phase->inv_output_size);
- phase->output_node->effect->register_uniform_vec2("output_texcoord_adjust", (float *)&phase->output_texcoord_adjust);
+ frag_shader.append(read_file("footer.comp"));
+ phase->compute_shader_node->effect->register_uniform_vec2("inv_output_size", (float *)&phase->inv_output_size);
+ phase->compute_shader_node->effect->register_uniform_vec2("output_texcoord_adjust", (float *)&phase->output_texcoord_adjust);
} else {
frag_shader.append(read_file("footer.frag"));
}
Phase *phase = new Phase;
phase->output_node = output;
- phase->is_compute_shader = output->effect->is_compute_shader();
+ phase->is_compute_shader = false;
+ phase->compute_shader_node = nullptr;
// If the output effect has one-to-one sampling, we try to trace this
// status down through the dependency chain. This is important in case
// output size); if we have one-to-one sampling, we don't have to break
// the phase.
output->one_to_one_sampling = output->effect->one_to_one_sampling();
+ output->strong_one_to_one_sampling = output->effect->strong_one_to_one_sampling();
// Effects that we have yet to calculate, but that we know should
// be in the current phase.
Node *node = effects_todo_this_phase.top();
effects_todo_this_phase.pop();
+ assert(node->effect->one_to_one_sampling() >= node->effect->strong_one_to_one_sampling());
+
if (node->effect->needs_mipmaps()) {
node->needs_mipmaps = true;
}
}
phase->effects.push_back(node);
+ if (node->effect->is_compute_shader()) {
+ phase->is_compute_shader = true;
+ phase->compute_shader_node = node;
+ }
// Find all the dependencies of this effect, and add them to the stack.
vector<Node *> deps = node->incoming_links;
start_new_phase = true;
}
- // Compute shaders currently always end phases.
- // (We might loosen this up in some cases in the future.)
- if (deps[i]->effect->is_compute_shader()) {
- start_new_phase = true;
- }
-
// Propagate information about needing mipmaps down the chain,
// breaking the phase if we notice an incompatibility.
//
}
}
- if (deps[i]->effect->sets_virtual_output_size()) {
+ if (deps[i]->effect->is_compute_shader()) {
+ // Only one compute shader per phase; we should have been stopped
+ // already due to the fact that compute shaders are not one-to-one.
+ assert(!phase->is_compute_shader);
+
+ // If all nodes so far are strong one-to-one, we can put them after
+ // the compute shader (ie., process them on the output).
+ start_new_phase = !node->strong_one_to_one_sampling;
+ } else if (deps[i]->effect->sets_virtual_output_size()) {
assert(deps[i]->effect->changes_output_size());
// If the next effect sets a virtual size to rely on OpenGL's
// bilinear sampling, we'll really need to break the phase here.
// Propagate the one-to-one status down through the dependency.
deps[i]->one_to_one_sampling = node->one_to_one_sampling &&
deps[i]->effect->one_to_one_sampling();
+ deps[i]->strong_one_to_one_sampling = node->strong_one_to_one_sampling &&
+ deps[i]->effect->strong_one_to_one_sampling();
}
}
}
void EffectChain::add_dummy_effect_if_needed()
{
Node *output = find_output_node();
- if (output->effect->is_compute_shader()) {
- Node *dummy = add_node(new IdentityEffect());
+
+ // See if the last effect that's not strong one-to-one is a compute shader.
+ Node *last_effect = output;
+ while (last_effect->effect->num_inputs() == 1 &&
+ last_effect->effect->strong_one_to_one_sampling()) {
+ last_effect = last_effect->incoming_links[0];
+ }
+ if (last_effect->effect->is_compute_shader()) {
+ Node *dummy = add_node(new ComputeShaderOutputDisplayEffect());
connect_nodes(output, dummy);
has_dummy_effect = true;
}
set<Phase *> generated_mipmaps;
- // We choose the simplest option of having one texture per output,
- // since otherwise this turns into an (albeit simple) register allocation problem.
+ // We keep one texture per output, but only for as long as we actually have any
+ // phases that need it as an input. (We don't make any effort to reorder phases
+ // to minimize the number of textures in play, as register allocation can be
+ // complicated and we rarely have much to gain, since our graphs are typically
+ // pretty linear.)
map<Phase *, GLuint> output_textures;
+ map<Phase *, int> ref_counts;
+ for (Phase *phase : phases) {
+ for (Phase *input : phase->inputs) {
+ ++ref_counts[input];
+ }
+ }
size_t num_phases = phases.size();
if (destinations.empty()) {
assert(num_phases >= 2);
assert(!phases.back()->is_compute_shader);
assert(phases.back()->effects.size() == 1);
- assert(phases.back()->effects[0]->effect->effect_type_id() == "IdentityEffect");
+ assert(phases.back()->effects[0]->effect->effect_type_id() == "ComputeShaderOutputDisplayEffect");
// We are rendering to a set of textures, so we can run the compute shader
// directly and skip the dummy phase.
// Find a texture for this phase.
inform_input_sizes(phase);
find_output_size(phase);
- GLuint tex_num = 0;
+ vector<DestinationTexture> phase_destinations;
if (!last_phase) {
- tex_num = resource_pool->create_2d_texture(intermediate_format, phase->output_width, phase->output_height);
- assert(tex_num != 0);
+ GLuint tex_num = resource_pool->create_2d_texture(intermediate_format, phase->output_width, phase->output_height);
output_textures.insert(make_pair(phase, tex_num));
+ phase_destinations.push_back(DestinationTexture{ tex_num, intermediate_format });
// The output texture needs to have valid state to be written to by a compute shader.
glActiveTexture(GL_TEXTURE0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
check_error();
} else if (phase->is_compute_shader) {
- // TODO: Support more than one destination.
assert(!destinations.empty());
- tex_num = destinations[0].texnum;
- assert(destinations[0].format == GL_RGBA16F);
- assert(destinations[0].texnum != 0);
+ phase_destinations = destinations;
}
- execute_phase(phase, output_textures, tex_num, &generated_mipmaps);
+ execute_phase(phase, output_textures, phase_destinations, &generated_mipmaps);
if (do_phase_timing) {
glEndQuery(GL_TIME_ELAPSED);
}
+
+ // Drop any input textures we don't need anymore.
+ for (Phase *input : phase->inputs) {
+ assert(ref_counts[input] > 0);
+ if (--ref_counts[input] == 0) {
+ resource_pool->release_2d_texture(output_textures[input]);
+ output_textures.erase(input);
+ }
+ }
}
for (const auto &phase_and_texnum : output_textures) {
void EffectChain::execute_phase(Phase *phase,
const map<Phase *, GLuint> &output_textures,
- GLuint dest_texture,
+ const std::vector<DestinationTexture> &destinations,
set<Phase *> *generated_mipmaps)
{
// Set up RTT inputs for this phase.
// And now the output.
GLuint fbo = 0;
if (phase->is_compute_shader) {
- assert(dest_texture != 0);
+ assert(!destinations.empty());
// This is currently the only place where we use image units,
- // so we can always use 0.
+ // so we can always start at 0. TODO: Support multiple destinations.
phase->outbuf_image_unit = 0;
- glBindImageTexture(phase->outbuf_image_unit, dest_texture, 0, GL_FALSE, 0, GL_WRITE_ONLY, GL_RGBA16F);
+ glBindImageTexture(phase->outbuf_image_unit, destinations[0].texnum, 0, GL_FALSE, 0, GL_WRITE_ONLY, destinations[0].format);
check_error();
phase->inv_output_size.x = 1.0f / phase->output_width;
phase->inv_output_size.y = 1.0f / phase->output_height;
phase->output_texcoord_adjust.x = 0.5f / phase->output_width;
phase->output_texcoord_adjust.y = 0.5f / phase->output_height;
- } else if (dest_texture != 0) {
- fbo = resource_pool->create_fbo(dest_texture);
+ } else if (!destinations.empty()) {
+ assert(destinations.size() == 1);
+ fbo = resource_pool->create_fbo(destinations[0].texnum);
glBindFramebuffer(GL_FRAMEBUFFER, fbo);
glViewport(0, 0, phase->output_width, phase->output_height);
}
projects / movit / blobdiff