#include <stddef.h>
#include <list>
#include <map>
+#include <stack>
#include <string>
#include <utility>
+#include <vector>
namespace movit {
// compiled program from the cache if possible. Keeps ownership of the
// program; you must call release_glsl_program() instead of deleting it
// when you no longer want it.
- GLuint compile_glsl_program(const std::string& vertex_shader, const std::string& fragment_shader);
+ //
+ // If <fragment_shader_outputs> contains more than one value, the given
+ // outputs will be bound to fragment shader output colors in the order
+ // they appear in the vector. Otherwise, output order is undefined and
+ // determined by the OpenGL driver.
+ GLuint compile_glsl_program(const std::string& vertex_shader,
+ const std::string& fragment_shader,
+ const std::vector<std::string>& frag_shader_outputs);
void release_glsl_program(GLuint glsl_program_num);
+ // Since uniforms belong to the program and not to the context,
+ // a given GLSL program number can't be used by more than one thread
+ // at a time. Thus, if two threads want to use the same program
+ // (usually because two EffectChains share them via caching),
+ // we will need to make a clone. use_glsl_program() makes such
+ // a clone if needed, calls glUseProgram(), and returns the real
+ // program number that was used; this must be given to
+ // unuse_glsl_program() to release it. unuse_glsl_program() does not
+ // actually change any OpenGL state, though.
+ GLuint use_glsl_program(GLuint glsl_program_num);
+ void unuse_glsl_program(GLuint instance_program_num);
+
// Allocate a 2D texture of the given internal format and dimensions,
// or fetch a previous used if possible. Unbinds GL_TEXTURE_2D afterwards.
// Keeps ownership of the texture; you must call release_2d_texture() instead
// is no more than <max_length> elements long.
void shrink_fbo_freelist(void *context, size_t max_length);
+ // Link the given vertex and fragment shaders into a full GLSL program.
+ // See compile_glsl_program() for explanation of <fragment_shader_outputs>.
+ static GLuint link_program(GLuint vs_obj,
+ GLuint fs_obj,
+ const std::vector<std::string>& fragment_shader_outputs);
+
// Protects all the other elements in the class.
pthread_mutex_t lock;
std::map<GLuint, int> program_refcount;
// A mapping from program number to vertex and fragment shaders.
- std::map<GLuint, std::pair<GLuint, GLuint> > program_shaders;
+ // Contains everything needed to re-link the program.
+ struct ShaderSpec {
+ GLuint vs_obj, fs_obj;
+ std::vector<std::string> fragment_shader_outputs;
+ };
+ std::map<GLuint, ShaderSpec> program_shaders;
+
+ // For each program, a list of other programs that are exactly like it.
+ // By default, will only contain the program itself, but due to cloning
+ // (see use_glsl_program()), may grow. Programs are taken off this list
+ // while they are in use (by use_glsl_program()).
+ std::map<GLuint, std::stack<GLuint> > program_instances;
+
+ // For each program, the master program that created it
+ // (inverse of program_instances).
+ std::map<GLuint, GLuint> program_masters;
// A list of programs that are no longer in use, most recently freed first.
// Once this reaches <program_freelist_max_length>, the last element