fixes

source/opengl/handles/shader_program_handle.cpp

@@ -0,0 +1,152 @@
+#include "opengl/handles/shader_program_handle.hpp"
+
+#include <string_view>
+// TODO remove
+#include "opengl/error.hpp"
+#include "util/logger.hpp"
+
+namespace zgl
+{
+
+shader_program_handle::attribute_support_type shader_program_handle::check_attribute_support(
+	const std::span<const shader_program_variable> attributes
+) const {
+	auto attribute_candidates = attribute_support_type{};
+
+	auto error = std::error_code{};
+	auto check_error = [&error, ec = static_cast<GLenum>(GL_NO_ERROR)]() mutable -> std::error_code&
+	{
+		ec = glGetError();
+		if (ec != GL_NO_ERROR) {
+			error = make_error_code(ec);
+		}
+		return error;
+	};
+
+	auto curr_attribute_flag = attribute_support_type{ 1 };
+	for (const auto& attribute : attributes) {
+		const auto location = glGetAttribLocation(program_id, attribute.name);
+		if (location == attribute.info.location)
+		{
+			attribute_candidates |= curr_attribute_flag;
+		}
+		curr_attribute_flag <<= 1;
+	}
+
+	auto supported_attributes = attribute_support_type{};
+
+	GLint count;
+	glGetProgramiv(program_id, GL_ACTIVE_ATTRIBUTES, &count);
+	if (check_error()) ztu::logger::error("GL_err: %", error.message());
+
+	for (GLint i{}; i != count and attribute_candidates; ++i)
+	{
+		GLenum type;
+		GLint size;
+		GLsizei name_length;
+		auto name = std::array<char, 256>{};
+		glGetActiveAttrib(
+			program_id, i,
+			name.size(),
+			&name_length,
+			&size, &type,
+			name.data()
+		);
+		if (check_error()) ztu::logger::error("GL_err: %", error.message());
+
+		const auto name_view = std::string_view(name.data(), name_length);
+
+		auto attribute_index = attribute_support_type{};
+		for (auto candidates = attribute_candidates; candidates; candidates >>= 1) {
+			if (candidates & 1)
+			{
+				const auto& attribute = attributes[attribute_index];
+				if (type == attribute.info.type and name_view == attribute.name)
+				{
+					const auto new_uniform_flag = attribute_support_type{ 1 } << attribute_index;
+					supported_attributes |= new_uniform_flag;
+					attribute_candidates ^= new_uniform_flag;
+				}
+			}
+			++attribute_index;
+		}
+	}
+
+	return supported_attributes;
+}
+
+shader_program_handle::uniform_support_type shader_program_handle::check_uniform_support(
+	const std::span<const shader_program_variable> uniforms
+) const {
+	auto uniform_candidates = uniform_support_type{};
+
+	auto error = std::error_code{};
+	auto check_error = [&error, ec = static_cast<GLenum>(GL_NO_ERROR)]() mutable -> std::error_code&
+	{
+		ec = glGetError();
+		if (ec != GL_NO_ERROR) {
+			error = make_error_code(ec);
+		}
+		return error;
+	};
+
+	auto curr_uniform_flag = uniform_support_type{ 1 };
+	for (const auto& uniform : uniforms)
+	{
+		const auto location = glGetUniformLocation(program_id, uniform.name);
+
+		if (location == uniform.info.location)
+		{
+			uniform_candidates |= curr_uniform_flag;
+			ztu::logger::debug("[%] '%': %.", program_id, uniform.name, location);
+		}
+		else
+		{
+			ztu::logger::debug("Expected '%' at % but was %.", uniform.name, uniform.info.location, location);
+		}
+		curr_uniform_flag <<= 1;
+	}
+
+	auto supported_uniforms = uniform_support_type{};
+
+	GLint count;
+	glGetProgramiv(program_id, GL_ACTIVE_UNIFORMS, &count);
+	if (check_error()) ztu::logger::error("GL_err: %", error.message());
+
+	for (GLint i{}; i != count and uniform_candidates; ++i)
+	{
+		GLenum type;
+		GLint size;
+		GLsizei name_length;
+		auto name = std::array<char, 256>{};
+		glGetActiveUniform(
+			program_id, i,
+			name.size(),
+			&name_length,
+			&size, &type,
+			name.data()
+		);
+		if (check_error()) ztu::logger::error("GL_err: %", error.message());
+
+		const auto name_view = std::string_view(name.data(), name_length);
+
+		auto uniform_index = uniform_support_type{};
+		for (auto candidates = uniform_candidates; candidates; candidates >>= 1)
+		{
+			if (candidates & 1)
+			{
+				const auto& uniform = uniforms[uniform_index];
+				if (type == uniform.info.type and name_view == uniform.name)
+				{
+					const auto new_uniform_flag = uniform_support_type{ 1 } << uniform_index;
+					supported_uniforms |= new_uniform_flag;
+					uniform_candidates ^= new_uniform_flag;
+				}
+			}
+			++uniform_index;
+		}
+	}
+
+	return supported_uniforms;
+}
+}