renderer.cxx

#include "renderer.h"
#include "gl/gl_tools.h"
 
namespace cgv {
    namespace render {
        render_style::~render_style()
        {
        }
        renderer::renderer() {}
        void renderer::manage_singleton(context& ctx, const std::string& renderer_name, int& ref_count, int ref_count_change)
        {
            switch (ref_count_change) {
            case 1:
                if (ref_count == 0) {
                    if (!init(ctx))
                        ctx.error(std::string("unable to initialize ") + renderer_name + " singleton");
                }
                ++ref_count;
                break;
            case 0:
                break;
            case -1:
                if (ref_count == 0)
                    ctx.error(std::string("attempt to decrease reference count of ") + renderer_name + " singleton below 0");
                else {
                    if (--ref_count == 0)
                        clear(ctx);
                }
                break;
            default:
                ctx.error(std::string("invalid change reference count outside {-1,0,1} for ") + renderer_name + " singleton");
            }
        }
        renderer::~renderer()
        {
            if (default_render_style)
                delete default_render_style;
            default_render_style = nullptr;
        }
        bool renderer::build_shader_program(context& ctx, shader_program& prog, const shader_compile_options& options) const
        {
            std::string prog_name = get_default_prog_name();
            if(!prog_name.empty())
                return prog.build_program(ctx, prog_name, options, true);
            return false;
        }
        void renderer::enable_attribute_array_manager(const context& ctx, attribute_array_manager& aam)
        {
            aam_ptr = &aam;
            if (has_attribute(ctx, "position"))
                has_positions = true;
            if (has_attribute(ctx, "color"))
                has_colors = true;
        }
        void renderer::disable_attribute_array_manager(const context& ctx, attribute_array_manager& aam)
        {
            has_positions = false;
            has_colors = false;
            if (ctx.core_profile)
                aam_ptr = &default_aam;
            else
                aam_ptr = 0;
        }
        void renderer::set_attribute_array_manager(const context& ctx, attribute_array_manager* _aam_ptr)
        {
            if (_aam_ptr)
                enable_attribute_array_manager(ctx, *_aam_ptr);
            else
                disable_attribute_array_manager(ctx, *aam_ptr);
        }
        bool renderer::set_attribute_array(const context& ctx, const std::string& name, type_descriptor element_type, const vertex_buffer& vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes)
        {
            int loc = get_prog_attribute_location(ctx, name);
            if(loc < 0)
                return false;
            if (aam_ptr)
                return aam_ptr->set_attribute_array(ctx, loc, element_type, vbo, offset_in_bytes, nr_elements, stride_in_bytes);
            enabled_attribute_arrays.insert(loc);
            return attribute_array_binding::set_global_attribute_array(ctx, loc, element_type, vbo, offset_in_bytes, nr_elements, stride_in_bytes);
        }
        bool renderer::remove_attribute_array(const context& ctx, const std::string& name)
        {
            int loc = get_prog_attribute_location(ctx, name);
            if(loc < 0)
                return false;
            if(aam_ptr) {
                aam_ptr->remove_attribute_array(ctx, loc);
                return true;
            }
            enabled_attribute_arrays.erase(loc);
            return true;
        }
        void renderer::set_position_array(const context& ctx, type_descriptor element_type, const vertex_buffer& vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes)
        {
            has_positions = true;
            set_attribute_array(ctx, "position", element_type, vbo, offset_in_bytes, nr_elements, stride_in_bytes);
        }
        void renderer::remove_position_array(const context& ctx) {
            has_positions = false;
            remove_attribute_array(ctx, "position");
        }
        void renderer::set_color_array(const context& ctx, type_descriptor element_type, const vertex_buffer& vbo, size_t offset_in_bytes, size_t nr_elements, unsigned stride_in_bytes)
        {
            has_colors = true;
            set_attribute_array(ctx, "color", element_type, vbo, offset_in_bytes, nr_elements, stride_in_bytes);
        }
        void renderer::remove_color_array(const context& ctx) {
            has_colors = false;
            remove_attribute_array(ctx, "color");
        }
        void renderer::remove_indices(const context& ctx)
        {
            if (!has_indices())
                return;
            if (aam_ptr)
                aam_ptr->remove_indices(ctx);
            index_buffer_ptr = 0;
            indices = 0;
            index_count = 0;
            index_type = cgv::type::info::TI_UNDEF;
        }
        bool renderer::validate_attributes(const context& ctx) const
        {
            // validate set attributes
            if (!has_positions) {
                ctx.error("renderer::enable() position attribute not set");
                return false;
            }
            return true;
        }
        void renderer::set_render_style(const render_style& _rs)
        {
            rs = &_rs;
        }
 
        bool renderer::build_program(context& ctx, shader_program& prog, const render_style& _rs)
        {
            auto* tmp = rs;
            rs = &_rs;
            shader_compile_options options;
            update_shader_program_options(options);
            bool res = build_shader_program(ctx, prog, options);
            rs = tmp;
            return res;
        }
 
        const render_style* renderer::get_style_ptr() const
        {
            if (rs)
                return rs;
            if (default_render_style)
                return default_render_style;
            default_render_style = create_render_style();
            return default_render_style;
        }
        void renderer::set_prog(shader_program& one_shot_prog)
        {
            prog_ptr = &one_shot_prog;
        }
 
        bool renderer::init(context& ctx)
        {
            if (ctx.core_profile) {
                default_aam.init(ctx);
                if (!aam_ptr)
                    aam_ptr = &default_aam;
            }
 
            if (!default_render_style)
                default_render_style = create_render_style();
 
            if (!rs)
                rs = default_render_style;
 
            if(prog_ptr == &prog) {
                update_shader_program_options(prog_options);
                if(!build_shader_program(ctx, prog, prog_options))
                    return false;
                last_prog_options = prog_options;
            }
            return default_render_style != 0;
        }
 
        bool renderer::validate_and_enable(context& ctx)
        {
            if (validate_attributes(ctx))
                return enable(ctx);
            return false;
        }
 
        bool renderer::enable(context& ctx)
        {
            if(prog_ptr == &prog) {
                update_shader_program_options(prog_options);
                if(prog_options != last_prog_options) {
                    if(prog.is_created())
                        prog.destruct(ctx);
                    if(!build_shader_program(ctx, prog, prog_options))
                        return false;
#ifndef _DEBUG
                }
#else
                    if(current_prog_render_count < 10)
                        std::cerr << "Performance warning: shader is rebuild! Consider using multiple instances of the renderer." << std::endl;
                    current_prog_render_count = 0;
                }
                ++current_prog_render_count;
#endif
                last_prog_options = prog_options;
            }
            bool res = ref_prog().enable(ctx);
            if (aam_ptr)
                res = aam_ptr->enable(ctx);
            return res;             
        }
 
        bool renderer::disable(context& ctx)
        {
            bool res = true;
            if (has_aam())
                res = aam_ptr->disable(ctx);
            else {
                if (ctx.core_profile) {
                    default_aam.disable(ctx);
                    for (int loc : enabled_attribute_arrays)
                        res = default_aam.aab.disable_array(ctx, loc) && res;
                }
                else {
                    for (int loc : enabled_attribute_arrays)
                        res = attribute_array_binding::disable_global_array(ctx, loc) && res;
                }
                enabled_attribute_arrays.clear();
                has_colors = false;
                has_positions = false;
                index_count = 0;
            }
            res = ref_prog().disable(ctx) && res;
            prog_ptr = &prog;
            return res;
        }
        void renderer::draw_impl(context& ctx, PrimitiveType type, size_t start, size_t count, bool use_strips, bool use_adjacency, uint32_t strip_restart_index)
        {
            if (use_strips && has_indices()) {
                glPrimitiveRestartIndex(strip_restart_index);
                glEnable(GL_PRIMITIVE_RESTART);
            }
            if (type == PT_LINES) {
                if (use_adjacency)
                    if (use_strips)
                        type = PT_LINE_STRIP_ADJACENCY;
                    else
                        type = PT_LINES_ADJACENCY;
                else
                    if (use_strips)
                        type = PT_LINE_STRIP;
            }
            else if (type == PT_TRIANGLES)
                if (use_adjacency)
                    if (use_strips)
                        type = PT_TRIANGLE_STRIP_ADJACENCY;
                    else
                        type = PT_TRIANGLES_ADJACENCY;
                else
                    if (use_strips)
                        type = PT_TRIANGLE_STRIP;
 
            GLenum pt = gl::map_to_gl(type);
            if (has_indices()) {
                bool aam_has_index_buffer = aam_ptr && aam_ptr->has_index_buffer();
                bool use_index_buffer = index_buffer_ptr && !aam_has_index_buffer;
                bool use_indices = !index_buffer_ptr && !aam_has_index_buffer;
                if (use_index_buffer)
                    index_buffer_ptr->bind(ctx, VBT_INDICES);
                const void* offset = reinterpret_cast<const uint8_t*>(use_indices ? indices : 0)
                                                + start * cgv::type::info::get_type_size(index_type);
                glDrawElements(pt, (GLsizei)count, gl::map_to_gl(index_type), offset);
                if (use_index_buffer)
                    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
            }
            else
                glDrawArrays(pt, (GLint)start, (GLsizei)count);
        }
        void renderer::draw_impl_instanced(context& ctx, PrimitiveType type, size_t start, size_t count, size_t instance_count, bool use_strips, bool use_adjacency, uint32_t strip_restart_index)
        {
            if (use_strips && has_indices()) {
                glPrimitiveRestartIndex(strip_restart_index);
                glEnable(GL_PRIMITIVE_RESTART);
            }
            if (type == PT_LINES) {
                if (use_adjacency)
                    if (use_strips)
                        type = PT_LINE_STRIP_ADJACENCY;
                    else
                        type = PT_LINES_ADJACENCY;
                else
                    if (use_strips)
                        type = PT_LINE_STRIP;
            }
            else if (type == PT_TRIANGLES)
                if (use_adjacency)
                    if (use_strips)
                        type = PT_TRIANGLE_STRIP_ADJACENCY;
                    else
                        type = PT_TRIANGLES_ADJACENCY;
                else
                    if (use_strips)
                        type = PT_TRIANGLE_STRIP;
            
            GLenum pt = gl::map_to_gl(type);
            if (has_indices()) {
                bool aam_has_index_buffer = aam_ptr && aam_ptr->has_index_buffer();
                bool use_index_buffer = index_buffer_ptr && !aam_has_index_buffer;
                bool use_indices = !index_buffer_ptr && !aam_has_index_buffer;
                if (use_index_buffer)
                    index_buffer_ptr->bind(ctx, VBT_INDICES);
                const void* offset = reinterpret_cast<const uint8_t*>(use_indices ? indices : 0)
                    + start * cgv::type::info::get_type_size(index_type);
                glDrawElementsInstanced(pt, (GLsizei)count, gl::map_to_gl(index_type), offset, (GLsizei)instance_count);
                if (use_index_buffer)
                    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
            }
            else
                glDrawArraysInstanced(pt, (GLint)start, (GLsizei)count, (GLsizei)instance_count);
        }
        void renderer::draw(context& ctx, size_t start, size_t count,
            bool use_strips, bool use_adjacency, uint32_t strip_restart_index)
        {
            draw_impl(ctx, PT_TRIANGLES, start, count, use_strips, use_adjacency, strip_restart_index);
        }
        bool renderer::render(context& ctx, size_t start, size_t count, bool use_strips, bool use_adjacency, uint32_t strip_restart_index)
        {
            if (!validate_and_enable(ctx))
                return false;
            draw(ctx, start, count, use_strips, use_adjacency, strip_restart_index);
            return disable(ctx);
        }
        void renderer::clear(const cgv::render::context& ctx)
        {
            prog.destruct(ctx);
        }
    }
}