From 0bf4ad9e4a9e1c97e92aa23a365405dfef89bd7c Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 17 Jan 2021 19:36:30 +0000
Subject: Big reshuffle

Fixes code quality warnings now picked up.
---
 gfx/gl/shader.cpp | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 gfx/gl/shader.cpp

(limited to 'gfx/gl/shader.cpp')

diff --git a/gfx/gl/shader.cpp b/gfx/gl/shader.cpp
new file mode 100644
index 0000000..33fdf61
--- /dev/null
+++ b/gfx/gl/shader.cpp
@@ -0,0 +1,100 @@
+#include "shader.h"
+#include "transform.h"
+#include <gfx/gl/shaders/fs-basicShader.h>
+#include <gfx/gl/shaders/vs-basicShader.h>
+#include <glm/glm.hpp>
+#include <stdexcept>
+
+Shader::Shader(const std::string &) :
+	m_program {glCreateProgram()}, m_shaders {CreateShader(
+													  (GLchar *)(basicShader_vs), basicShader_vs_len, GL_VERTEX_SHADER),
+										   CreateShader(
+												   (GLchar *)basicShader_fs, basicShader_fs_len, GL_FRAGMENT_SHADER)},
+	m_uniforms {}
+{
+	for (auto m_shader : m_shaders) {
+		glAttachShader(m_program, m_shader);
+	}
+
+	glBindAttribLocation(m_program, 0, "position");
+	glBindAttribLocation(m_program, 1, "texCoord");
+	glBindAttribLocation(m_program, 2, "normal");
+
+	glLinkProgram(m_program);
+	CheckShaderError(m_program, GL_LINK_STATUS, true, "Error linking shader program");
+
+	glValidateProgram(m_program);
+	CheckShaderError(m_program, GL_VALIDATE_STATUS, true, "Invalid shader program");
+
+	m_uniforms = {glGetUniformLocation(m_program, "MVP"), glGetUniformLocation(m_program, "Normal"),
+			glGetUniformLocation(m_program, "lightDirection")};
+}
+
+Shader::~Shader()
+{
+	for (auto m_shader : m_shaders) {
+		glDetachShader(m_program, m_shader);
+		glDeleteShader(m_shader);
+	}
+
+	glDeleteProgram(m_program);
+}
+
+void
+Shader::Bind() const
+{
+	glUseProgram(m_program);
+}
+
+void
+Shader::Update(const Transform & transform, const Camera & camera) const
+{
+	glm::mat4 MVP = transform.GetMVP(camera);
+	glm::mat4 Normal = transform.GetModel();
+
+	glUniformMatrix4fv(m_uniforms[0], 1, GL_FALSE, &MVP[0][0]);
+	glUniformMatrix4fv(m_uniforms[1], 1, GL_FALSE, &Normal[0][0]);
+	glUniform3f(m_uniforms[2], 0.0F, 0.0F, 1.0F);
+}
+
+void
+Shader::CheckShaderError(GLuint shader, GLuint flag, bool isProgram, const std::string & errorMessage)
+{
+	GLint success = 0;
+	std::array<GLchar, 1024> error {};
+
+	if (isProgram) {
+		glGetProgramiv(shader, flag, &success);
+	}
+	else {
+		glGetShaderiv(shader, flag, &success);
+	}
+
+	if (success == GL_FALSE) {
+		if (isProgram) {
+			glGetProgramInfoLog(shader, error.size(), nullptr, error.data());
+		}
+		else {
+			glGetShaderInfoLog(shader, error.size(), nullptr, error.data());
+		}
+
+		throw std::runtime_error {errorMessage + ": '" + std::string {error.data(), error.size()} + "'"};
+	}
+}
+
+GLuint
+Shader::CreateShader(const GLchar * text, GLint len, unsigned int type)
+{
+	GLuint shader = glCreateShader(type);
+
+	if (shader == 0) {
+		throw std::runtime_error {"Error compiling shader type " + std::to_string(type)};
+	}
+
+	glShaderSource(shader, 1, &text, &len);
+	glCompileShader(shader);
+
+	CheckShaderError(shader, GL_COMPILE_STATUS, false, "Error compiling shader!");
+
+	return shader;
+}
-- 
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