Transformations etc

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "extern/stb"]
 	path = extern/stb
 	url = https://github.com/nothings/stb.git
+[submodule "lib/glm"]
+	path = lib/glm
+	url = https://github.com/g-truc/glm.git

CMakeLists.txt

@@ -2,10 +2,13 @@ cmake_minimum_required(VERSION 3.24.2)
 
 project(Hohmann VERSION 1.0)
 
+#### Sources
 file(GLOB SOURCES src/*.cpp headers/*.hpp)
 add_executable(Hohmann ${SOURCES})
 
-# GLFW submodule
+
+#### Libs
+# GLFW 
 set(GLFW_BUILD_DOCS OFF CACHE BOOL "" FORCE)
 set(GLFW_BUILD_TESTS OFF CACHE BOOL "" FORCE)
 set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
@@ -14,10 +17,13 @@ add_subdirectory(lib/glfw)
 # GLAD
 add_subdirectory(lib/glad)
 
-# External headers & sources
+# GLM
+add_subdirectory(lib/glm)
+
+#### External headers & sources
 file(GLOB EXTERN_SOURCES extern/*)
 include_directories(${EXTERN_SOURCES})
 link_directories(${EXTERN_SOURCES})
 
-# Linking
-target_link_libraries(Hohmann PRIVATE glfw glad)
+#### Linking
+target_link_libraries(Hohmann PRIVATE glfw glad glm)

headers/shaders.hpp

@@ -1,3 +1,4 @@
+#include "glm/fwd.hpp"
 #include <glad/glad.h>
 #include <string>
 #include <vector>
@@ -18,5 +19,9 @@ namespace Shaders {
 			void setBool(const std::string &name, bool val) const;
 			void setInt(const std::string &name, int val) const;
 			void setFloat(const std::string &name, float val) const;
+			void setMat4(const std::string &name, glm::mat4 val) const;
+
+		private:
+			unsigned int uniLocation(const std::string &name) const;
 	};
 }

headers/textures.hpp

@@ -7,7 +7,7 @@ namespace Textures {
 			unsigned int id;
 			Texture2D(const char* t_src);
 			void load();
-			void use();
+			void bind();
 		private:
 			const char* texture_src;
 			int width, height, nrChannels;

lib/glm

@@ -0,0 +1 @@
+Subproject commit 0a6d3334ea747b0023d232572d3aff61dc6b48e6

shaders/vertex.glsl

@@ -6,8 +6,15 @@ layout (location = 2) in vec2 aTexCoord;
 out vec4 VertexColor;
 out vec2 TexCoord;
 
+uniform mat4 transform = mat4(
+		1.0, 0.0, 0.0, 0.0, 
+		0.0, 1.0, 0.0, 0.0,
+		0.0, 0.0, 1.0, 0.0,
+		0.0, 0.0, 0.0, 1.0
+		);
+
 void main() {
-	gl_Position = vec4(aPos, 1.0);
+	gl_Position = transform * vec4(aPos, 1.0);
 	VertexColor = vec4(aColor, 1.0);
 	TexCoord = aTexCoord;
 } 

src/main.cpp

@@ -1,5 +1,8 @@
 #include <glad/glad.h>
 #include <GLFW/glfw3.h>
+#include <glm/glm.hpp>
+#include <glm/gtc/matrix_transform.hpp>
+#include <glm/gtc/type_ptr.hpp>
 #include <stdio.h>
 #include <vector>
 #include <math.h>
@@ -68,35 +71,30 @@ RenderObj preRenderCallback(unsigned int indices[], unsigned int indices_count,
 	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, VERTEX_ATTRIB_PTR_SIZE, (void*)(6*sizeof(float)));
 	glEnableVertexAttribArray(2);
 
-
 	Shaders::Shader shader(VERT_SHADER_SRC_FILE, FRAG_SHADER_SRC_FILE);
 	Textures::Texture2D texture(RUSTY_METAL_TEXTURE);
 
 	return RenderObj {EBO, shader, texture};
 }
 
-void renderCallback(RenderObj ro) {
-	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+void renderCallback() {
+	// Make background
+	glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
 	glClear(GL_COLOR_BUFFER_BIT);
+}
 
-	float time = glfwGetTime();
-	float gVal = (sin(time) / 1.5f) + 0.5f;
-
-
-	ro.shader.use();
-	ro.shader.setFloat("r", gVal);
-	ro.shader.setFloat("g", gVal);
-	ro.shader.setFloat("b", gVal);
+void renderObject(RenderObj ro, glm::mat4 T) {
+	// Bind the texture
+	ro.texture.bind();
 
-	ro.texture.use();
+	ro.shader.setMat4("transform", T);
 
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ro.EBO);
 	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
 }
 
 int main() {
-	glfwInit();
-	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwInit(); glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
 	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
@@ -116,9 +114,9 @@ int main() {
 
 	float verts[] = {
 		 0.5f,  0.5f, 0.0f, 1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 
-		 0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f,
-		-0.5f, -0.5f, 0.0f, 1.0f, 1.0f, 0.0f, -1.0f, -1.0f,
-		-0.5f,  0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, -1.0f
+		 0.5f, -0.5f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,
+		-0.5f, -0.5f, 0.0f, 1.0f, 1.0f, 1.0f, -1.0f, -1.0f,
+		-0.5f,  0.5f, 0.0f, 1.0f, 1.0f, 1.0f, 1.0f, -1.0f
 	};
 	// Vert struc: x y z  r g b  tx ty
 
@@ -140,7 +138,31 @@ int main() {
 		processInput(win);
 
 		// rendering
-		renderCallback(ro);
+		renderCallback();
+
+		/* OBJECT RENDERING */
+		float time = glfwGetTime();
+		float gVal = (sin(time) / 1.5f) + 0.5f;
+
+		// Coloring uniform
+		ro.shader.use();
+		// ro.shader.setFloat("r", gVal);
+		// ro.shader.setFloat("g", gVal);
+		// ro.shader.setFloat("b", gVal);
+
+		// Transformation
+		float rotang = time;
+
+		glm::mat4 T = glm::mat4(1.0f);
+		T = glm::rotate(T, rotang, glm::vec3(0.0, 0.707, 0.707));
+		T = glm::scale(T, glm::vec3(0.5, 0.5, 0.5));
+		renderObject(ro, T);
+
+		glm::mat4 T2 = glm::mat4(1.0f);
+		T2 = glm::translate(T2, glm::vec3(-0.5, 0.4, 0.0));
+		T2 = glm::rotate(T2, rotang, glm::vec3(0.707, 0.707, 0.0));
+		T2 = glm::scale(T2, glm::vec3(0.5, 0.5, 0.2));
+		renderObject(ro, T2);
 
 		// glfw
 		glfwSwapBuffers(win);

src/shaders.cpp

@@ -7,6 +7,8 @@
 
 #include "../headers/shaders.hpp"
 
+#include <glm/gtc/type_ptr.hpp>
+
 namespace Shaders {
 	std::string loadSourceFromFile(const char* fp) {
 		std::string src;
@@ -88,14 +90,23 @@ namespace Shaders {
 	void Shader::use() { glUseProgram(id); }
 
 	void Shader::setInt(const std::string &name, int val) const {
-		glUniform1i(glGetUniformLocation(id, name.c_str()), val);
+		glUniform1i(uniLocation(name), val);
 	}
 
 	void Shader::setFloat(const std::string &name, float val) const {
-		glUniform1f(glGetUniformLocation(id, name.c_str()), val);
+		glUniform1f(uniLocation(name), val);
 	}
 
 	void Shader::setBool(const std::string &name, bool val) const {
-		glUniform1i(glGetUniformLocation(id, name.c_str()), (int)val)	;
+		glUniform1i(uniLocation(name), (int)val);
+	}
+
+	void Shader::setMat4(const std::string &name, glm::mat4 val) const {
+		glUniformMatrix4fv(uniLocation(name), 1, GL_FALSE, glm::value_ptr(val));
+	};
+
+	// Private stuff
+	unsigned int Shader::uniLocation(const std::string &name) const {
+		return glGetUniformLocation(id, name.c_str());
 	}
 }

src/textures.cpp

@@ -40,7 +40,7 @@ namespace Textures {
 		stbi_image_free(data);
 	}
 
-	void Texture2D::use() {
+	void Texture2D::bind() {
 		glBindTexture(GL_TEXTURE_2D, id);
 	}
 }