I hyper-focued on refactoring again

- I put a cool-sounding "we are number one" remix on repeat and straight
  up grinded the entire repository to a better state until 03:09 AM. I
  guess I have something wrong in my brain that makes me do this shit

1 files changed, 223 insertions, 0 deletions

diff --git a/game/client/program.cc b/game/client/program.cc
new file mode 100644
index 0000000..7b908af
--- /dev/null
+++ b/game/client/program.cc
@@ -0,0 +1,223 @@
+#include "client/pch.hh"
+
+#include "client/program.hh"
+
+#include "core/utils/string.hh"
+
+// This fills up the array of source lines and figures out
+// which lines are to be dynamically resolved as variant macros
+static void parse_source(const char* source, std::vector<std::string>& out_lines, std::vector<GL_VariedMacro>& out_variants)
+{
+    std::string line;
+    std::istringstream stream = std::istringstream(source);
+    unsigned long line_number = 0UL;
+
+    out_lines.clear();
+    out_variants.clear();
+
+    while(std::getline(stream, line)) {
+        unsigned int macro_index = {};
+        char macro_name[128] = {};
+
+        if(std::sscanf(line.c_str(), " # pragma variant [ %u ] %127[^, \"\t\r\n]", &macro_index, &macro_name) == 2) {
+            if(out_variants.size() <= macro_index) {
+                out_variants.resize(macro_index + 1U);
+            }
+
+            out_variants[macro_index].name = macro_name;
+            out_variants[macro_index].line = line_number;
+            out_variants[macro_index].value = std::numeric_limits<unsigned int>::max();
+
+            out_lines.push_back(std::string());
+            line_number += 1UL;
+        } else {
+            out_lines.push_back(line);
+            line_number += 1UL;
+        }
+    }
+}
+
+static GLuint compile_shader(const char* path, const char* source, GLenum shader_stage)
+{
+    GLuint shader = glCreateShader(shader_stage);
+    glShaderSource(shader, 1, &source, nullptr);
+    glCompileShader(shader);
+
+    GLint info_log_length;
+    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &info_log_length);
+
+    if(info_log_length >= 2) {
+        std::basic_string<GLchar> info_log;
+        info_log.resize(info_log_length);
+        glGetShaderInfoLog(shader, info_log_length, nullptr, info_log.data());
+        spdlog::info("gl_program: {}: shader information:", path);
+        spdlog::info(info_log);
+    }
+
+    GLint compile_status;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
+
+    if(!compile_status) {
+        glDeleteShader(shader);
+        return 0;
+    }
+
+    return shader;
+}
+
+bool GL_Program::setup(const char* vpath, const char* fpath)
+{
+    destroy();
+
+    vert_path = std::string(vpath);
+    frag_path = std::string(fpath);
+
+    auto vfile = PHYSFS_openRead(vpath);
+
+    if(vfile == nullptr) {
+        spdlog::warn("gl_program: {}: {}", vpath, PHYSFS_getErrorByCode(PHYSFS_getLastErrorCode()));
+        return false;
+    }
+
+    auto vsource = std::string(PHYSFS_fileLength(vfile), char(0x00));
+    PHYSFS_readBytes(vfile, vsource.data(), vsource.size());
+    PHYSFS_close(vfile);
+
+    auto ffile = PHYSFS_openRead(fpath);
+
+    if(ffile == nullptr) {
+        spdlog::warn("gl_program: {}: {}", fpath, PHYSFS_getErrorByCode(PHYSFS_getLastErrorCode()));
+        return false;
+    }
+
+    auto fsource = std::string(PHYSFS_fileLength(ffile), char(0x00));
+    PHYSFS_readBytes(ffile, fsource.data(), fsource.size());
+    PHYSFS_close(ffile);
+
+    parse_source(vsource.c_str(), vert_source, vert_variants);
+    parse_source(fsource.c_str(), frag_source, frag_variants);
+
+    needs_update = true;
+    handle = 0;
+
+    return true;
+}
+
+bool GL_Program::update(void)
+{
+    if(!needs_update) {
+        // The program is already up to
+        // date with the internal state
+        return true;
+    }
+
+    for(const auto& macro : vert_variants)
+        vert_source[macro.line] = std::format("#define {} {}", macro.name, macro.value);
+    for(const auto& macro : frag_variants)
+        frag_source[macro.line] = std::format("#define {} {}", macro.name, macro.value);
+
+    std::string vsource(utils::join(vert_source, "\r\n"));
+    std::string fsource(utils::join(frag_source, "\r\n"));
+
+    GLuint vert = compile_shader(vert_path.c_str(), vsource.c_str(), GL_VERTEX_SHADER);
+    GLuint frag = compile_shader(frag_path.c_str(), fsource.c_str(), GL_FRAGMENT_SHADER);
+
+    if(!vert || !frag) {
+        // needs_update = false;
+        glDeleteShader(frag);
+        glDeleteShader(vert);
+        return false;
+    }
+
+    handle = glCreateProgram();
+    glAttachShader(handle, vert);
+    glAttachShader(handle, frag);
+    glLinkProgram(handle);
+
+    GLint info_log_length;
+    glGetProgramiv(handle, GL_INFO_LOG_LENGTH, &info_log_length);
+
+    if(info_log_length >= 2) {
+        std::basic_string<GLchar> info_log;
+        info_log.resize(info_log_length);
+        glGetProgramInfoLog(handle, info_log_length, nullptr, info_log.data());
+        spdlog::info("gl_program: [{}; {}]: program information", vert, frag);
+        spdlog::info(info_log);
+    }
+
+    glDeleteShader(frag);
+    glDeleteShader(vert);
+
+    GLint link_status;
+    glGetProgramiv(handle, GL_LINK_STATUS, &link_status);
+
+    if(!link_status) {
+        // needs_update = false;
+        glDeleteProgram(handle);
+        return false;
+    }
+
+    for(auto& uniform : uniforms) {
+        // NOTE: GL seems to silently ignore invalid uniform
+        // locations (-1); should we write something into logs about this?
+        uniform.location = glGetUniformLocation(handle, uniform.name.c_str());
+    }
+
+    needs_update = false;
+    return true;
+}
+
+void GL_Program::destroy(void)
+{
+    if(handle) {
+        glDeleteProgram(handle);
+        handle = 0;
+    }
+
+    uniforms.clear();
+
+    frag_variants.clear();
+    frag_source.clear();
+    frag_path = std::string();
+
+    vert_variants.clear();
+    vert_source.clear();
+    vert_path = std::string();
+
+    needs_update = false;
+}
+
+std::size_t GL_Program::add_uniform(const char* name)
+{
+    for(std::size_t i = 0; i < uniforms.size(); ++i) {
+        if(!uniforms[i].name.compare(name)) {
+            return i;
+        }
+    }
+
+    const std::size_t index = uniforms.size();
+    uniforms.push_back(GL_Uniform());
+    uniforms[index].location = -1;
+    uniforms[index].name = name;
+    return index;
+}
+
+void GL_Program::set_variant_vert(unsigned int variant, unsigned int value)
+{
+    if(variant < vert_variants.size()) {
+        if(value != vert_variants[variant].value) {
+            vert_variants[variant].value = value;
+            needs_update = true;
+        }
+    }
+}
+
+void GL_Program::set_variant_frag(unsigned int variant, unsigned int value)
+{
+    if(variant < frag_variants.size()) {
+        if(value != frag_variants[variant].value) {
+            frag_variants[variant].value = value;
+            needs_update = true;
+        }
+    }
+}