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diff --git a/dev/MinGfx/src/shader_program.cc b/dev/MinGfx/src/shader_program.cc
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+++ b/dev/MinGfx/src/shader_program.cc
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+/*
+ Copyright (c) 2017,2018 Regents of the University of Minnesota.
+ All Rights Reserved.
+ See corresponding header file for details.
+ */
+
+#include "shader_program.h"
+
+#include "opengl_headers.h"
+
+#include <vector>
+#include <fstream>
+
+
+namespace mingfx {
+
+
+ShaderProgram::ShaderProgram() : vertexShader_(0), fragmentShader_(0), program_(0) {
+}
+
+ShaderProgram::~ShaderProgram() {
+}
+
+bool ShaderProgram::initialized() {
+ return (program_ != 0);
+}
+
+bool ShaderProgram::AddVertexShaderFromSource(const std::string &vertexSource) {
+ // https://www.khronos.org/opengl/wiki/Shader_Compilation
+
+ // Create an empty vertex shader handle
+ vertexShader_ = glCreateShader(GL_VERTEX_SHADER);
+
+ // Send the vertex shader source code to GL
+ // Note that std::string's .c_str is NULL character terminated.
+ const GLchar *source = (const GLchar *)vertexSource.c_str();
+ glShaderSource(vertexShader_, 1, &source, 0);
+
+ // Compile the vertex shader
+ glCompileShader(vertexShader_);
+
+ GLint isCompiled = 0;
+ glGetShaderiv(vertexShader_, GL_COMPILE_STATUS, &isCompiled);
+ if (isCompiled == GL_FALSE) {
+ GLint maxLength = 0;
+ glGetShaderiv(vertexShader_, GL_INFO_LOG_LENGTH, &maxLength);
+
+ // The maxLength includes the NULL character
+ std::vector<GLchar> infoLog(maxLength);
+ glGetShaderInfoLog(vertexShader_, maxLength, &maxLength, &infoLog[0]);
+
+ // We don't need the shader anymore.
+ glDeleteShader(vertexShader_);
+
+ std::cerr << "ShaderProgram: Error compiling vertex shader program: " << std::endl;
+ std::cerr << &infoLog[0] << std::endl;
+ std::cerr << vertexSource << std::endl;
+ return false;
+ }
+ return true;
+}
+
+bool ShaderProgram::AddVertexShaderFromFile(const std::string &file) {
+ std::cout << "Loading vertex shader from file: " << file << std::endl;
+ std::string source;
+ std::string line;
+ std::ifstream myfile (file);
+ if (myfile.is_open()) {
+ while (std::getline(myfile, line)) {
+ source += line + "\n";
+ }
+ myfile.close();
+ return AddVertexShaderFromSource(source);
+ }
+ else {
+ std::cerr << "ShaderProgram: Cannot open file " << file << std::endl;
+ return false;
+ }
+}
+
+
+
+bool ShaderProgram::AddFragmentShaderFromSource(const std::string &fragmentSource) {
+ // https://www.khronos.org/opengl/wiki/Shader_Compilation
+
+ // Create an empty fragment shader handle
+ fragmentShader_ = glCreateShader(GL_FRAGMENT_SHADER);
+
+ // Send the fragment shader source code to GL
+ // Note that std::string's .c_str is NULL character terminated.
+ const GLchar *source = (const GLchar *)fragmentSource.c_str();
+ glShaderSource(fragmentShader_, 1, &source, 0);
+
+ // Compile the fragment shader
+ glCompileShader(fragmentShader_);
+
+ GLint isCompiled = 0;
+ glGetShaderiv(fragmentShader_, GL_COMPILE_STATUS, &isCompiled);
+ if (isCompiled == GL_FALSE) {
+ GLint maxLength = 0;
+ glGetShaderiv(fragmentShader_, GL_INFO_LOG_LENGTH, &maxLength);
+
+ // The maxLength includes the NULL character
+ std::vector<GLchar> infoLog(maxLength);
+ glGetShaderInfoLog(fragmentShader_, maxLength, &maxLength, &infoLog[0]);
+
+ // We don't need the shader anymore.
+ glDeleteShader(fragmentShader_);
+
+ std::cerr << "ShaderProgram: Error compiling fragment shader program: " << std::endl;
+ std::cerr << &infoLog[0] << std::endl;
+ std::cerr << fragmentSource << std::endl;
+ return false;
+ }
+ return true;
+}
+
+
+bool ShaderProgram::AddFragmentShaderFromFile(const std::string &file) {
+ std::cout << "Loading fragment shader from file: " << file << std::endl;
+ std::string source;
+ std::string line;
+ std::ifstream myfile (file);
+ if (myfile.is_open()) {
+ while (std::getline(myfile, line)) {
+ source += line + "\n";
+ }
+ myfile.close();
+ return AddFragmentShaderFromSource(source);
+ }
+ else {
+ std::cerr << "ShaderProgram: Cannot open file " << file << std::endl;
+ return false;
+ }
+}
+
+
+bool ShaderProgram::LinkProgram() {
+ if (!vertexShader_) {
+ std::cerr << "ShaderProgram: Error linking program. A vertex shader must be added and successfully compiled before the program can be linked." << std::endl;
+ return false;
+ }
+ if (!fragmentShader_) {
+ std::cerr << "ShaderProgram: Error linking program. A fragment shader must be added and successfully compiled before the program can be linked." << std::endl;
+ return false;
+ }
+
+ // Vertex and fragment shaders are successfully compiled.
+ // Now time to link them together into a program.
+ // Get a program object.
+ program_ = glCreateProgram();
+
+ // Attach our shaders to our program
+ glAttachShader(program_, vertexShader_);
+ glAttachShader(program_, fragmentShader_);
+
+ // Link our program
+ glLinkProgram(program_);
+
+ // Note the different functions here: glGetProgram* instead of glGetShader*.
+ GLint isLinked = 0;
+ glGetProgramiv(program_, GL_LINK_STATUS, (int *)&isLinked);
+ if (isLinked == GL_FALSE) {
+ GLint maxLength = 0;
+ glGetProgramiv(program_, GL_INFO_LOG_LENGTH, &maxLength);
+
+ // The maxLength includes the NULL character
+ std::vector<GLchar> infoLog(maxLength);
+ glGetProgramInfoLog(program_, maxLength, &maxLength, &infoLog[0]);
+
+ // We don't need the program anymore.
+ glDeleteProgram(program_);
+ // Don't leak shaders either.
+ glDeleteShader(vertexShader_);
+ glDeleteShader(fragmentShader_);
+
+ std::cerr << "ShaderProgram: Error linking program: " << std::endl;
+ std::cerr << &infoLog[0] << std::endl;
+ return false;
+ }
+
+ // Always detach shaders after a successful link.
+ glDetachShader(program_, vertexShader_);
+ glDetachShader(program_, fragmentShader_);
+
+ return true;
+}
+
+
+void ShaderProgram::UseProgram() {
+ if (!initialized()) {
+ std::cerr << "ShaderProgram: Warning cannot UseProgram() until it shaders have been added and linked. Calling LinkProgram() for you now." << std::endl;
+ LinkProgram();
+ }
+ glUseProgram(program_);
+}
+
+
+void ShaderProgram::StopProgram() {
+ glUseProgram(0);
+}
+
+
+// MinGfx math types
+void ShaderProgram::SetUniform(const std::string &name, const Point2 &p) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform2f(loc, p[0], p[1]);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, const Vector2 &v) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform2f(loc, v[0], v[1]);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, const Point3 &p) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform3f(loc, p[0], p[1], p[2]);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, const Vector3 &v) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform3f(loc, v[0], v[1], v[2]);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, const Matrix4 &m) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniformMatrix4fv(loc, 1, GL_FALSE, m.value_ptr());
+}
+
+void ShaderProgram::SetUniform(const std::string &name, const Color &c) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform4f(loc, c[0], c[1], c[2], c[3]);
+}
+
+
+// built-in types
+void ShaderProgram::SetUniform(const std::string &name, int i) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1i(loc, i);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, unsigned int ui) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1ui(loc, ui);
+}
+
+void ShaderProgram::SetUniform(const std::string &name, float f) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1f(loc, f);
+}
+
+
+
+// built-in types - arrays
+void ShaderProgram::SetUniformArray1(const std::string &name, int *i, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1iv(loc, count, i);
+}
+
+void ShaderProgram::SetUniformArray1(const std::string &name, unsigned int *ui, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1uiv(loc, count, ui);
+}
+
+void ShaderProgram::SetUniformArray1(const std::string &name, float *f, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1fv(loc, count, f);
+}
+
+
+void ShaderProgram::SetUniformArray2(const std::string &name, int *i, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform2iv(loc, count, i);
+}
+
+void ShaderProgram::SetUniformArray2(const std::string &name, unsigned int *ui, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform2uiv(loc, count, ui);
+}
+
+void ShaderProgram::SetUniformArray2(const std::string &name, float *f, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform2fv(loc, count, f);
+}
+
+
+void ShaderProgram::SetUniformArray3(const std::string &name, int *i, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform3iv(loc, count, i);
+}
+
+void ShaderProgram::SetUniformArray3(const std::string &name, unsigned int *ui, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform3uiv(loc, count, ui);
+}
+
+void ShaderProgram::SetUniformArray3(const std::string &name, float *f, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform3fv(loc, count, f);
+}
+
+
+void ShaderProgram::SetUniformArray4(const std::string &name, int *i, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform4iv(loc, count, i);
+}
+
+void ShaderProgram::SetUniformArray4(const std::string &name, unsigned int *ui, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform4uiv(loc, count, ui);
+}
+
+void ShaderProgram::SetUniformArray4(const std::string &name, float *f, int count) {
+ UseProgram();
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform4fv(loc, count, f);
+}
+
+
+
+void ShaderProgram::BindTexture(const std::string &name, const Texture2D &tex) {
+ UseProgram();
+
+ int texUnit = 0;
+
+ std::map<std::string,int>::const_iterator it = texBindings_.find(name);
+ if (it != texBindings_.end()) {
+ // Found: This sampler was already bound to a tex unit, so use the same one
+ texUnit = texBindings_[name];
+ }
+ else {
+ // Not found: This sampler was not already bound to a tex unit, so loop through the
+ // past/current bindings and pick the next available texUnit
+ std::map<std::string,int>::const_iterator it2;
+ for (it2 = texBindings_.begin(); it2 != texBindings_.end(); ++it2) {
+ if (texUnit <= it2->second) {
+ texUnit = it2->second + 1;
+ }
+ }
+ // save it for future reference
+ texBindings_[name] = texUnit;
+ }
+
+ // associate the named shader program sampler variable with the selected texture unit
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1i(loc, texUnit);
+ // bind the opengl texture handle to the same texture unit
+ glActiveTexture(GL_TEXTURE0 + texUnit);
+ glBindTexture(GL_TEXTURE_2D, tex.opengl_id());
+}
+
+void ShaderProgram::BindTexture(const std::string &name, const Texture2D &tex, int texUnit) {
+ UseProgram();
+
+ texBindings_[name] = texUnit;
+
+ // associate the named shader program sampler variable with the selected texture unit
+ GLint loc = glGetUniformLocation(program_, name.c_str());
+ glUniform1i(loc, texUnit);
+ // bind the opengl texture handle to the same texture unit
+ glActiveTexture(GL_TEXTURE0 + texUnit);
+ glBindTexture(GL_TEXTURE_2D, tex.opengl_id());
+}
+
+
+
+} // end namespace
+
+