Orbiting via 3D Transformations

Models/main.cpp

@@ -7,6 +7,7 @@
 #include <glm/gtc/type_ptr.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <array>
+#include <stack>
 
 #define numVAOs 1
 #define numVBOs 2
@@ -16,11 +17,11 @@ GLuint vao[numVAOs];
 GLuint vbo[numVBOs];
 
 glm::vec3 camera;
-glm::vec3 cubeLoc,pyramidLoc;
 GLuint mvLoc,projLoc;
 int width, height;
 float aspect;
 glm::mat4 mMat, pMat, vMat, mvMat;
+std::stack<glm::mat4>transforms;
 
 void setupVertices(void) { // 36 vertices, 12 triangles, makes 2x2x2 cube placed at origin
    float cubePositions[108] = {
@@ -58,14 +59,27 @@ void setupVertices(void) { // 36 vertices, 12 triangles, makes 2x2x2 cube placed
 
 void init(GLFWwindow* window) {
     renderingProgram=utils::createShaderProgram("vertShader.glsl","fragShader.glsl");
-    camera={0.0f,0.0f,-8.0f};
-    cubeLoc={0.0f,-2.0f,0.0f};
-    pyramidLoc={4.0f,4.0f,-4.0f};
+    camera={0.0f,0.0f,-12.0f};
     setupVertices();
 }
 
 double lastTime=0;
 
+void DrawCube(){
+    glUniformMatrix4fv(mvLoc,1,GL_FALSE,glm::value_ptr(mMat));
+    glUniformMatrix4fv(projLoc,1,GL_FALSE,glm::value_ptr(pMat));
+    glBindBuffer(GL_ARRAY_BUFFER,vbo[0]);
+    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0);
+    glDrawArrays(GL_TRIANGLES,0,36);
+}
+void DrawSquarePyramid(){
+    glUniformMatrix4fv(mvLoc,1,GL_FALSE,glm::value_ptr(mMat));
+    glUniformMatrix4fv(projLoc,1,GL_FALSE,glm::value_ptr(pMat));
+    glBindBuffer(GL_ARRAY_BUFFER,vbo[1]);
+    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0);
+    glDrawArrays(GL_TRIANGLES,0,18);
+}
+
 void display(GLFWwindow* window, double currentTime) {
     double elapsedTime=currentTime-lastTime;
     lastTime=currentTime;
@@ -77,6 +91,7 @@ void display(GLFWwindow* window, double currentTime) {
     glUseProgram(renderingProgram);
     glEnable(GL_DEPTH_TEST);
     glDepthFunc(GL_LEQUAL);
+    glEnableVertexAttribArray(0);
 
     mvLoc=glGetUniformLocation(renderingProgram,"mv_matrix");
     projLoc=glGetUniformLocation(renderingProgram,"proj_matrix");
@@ -86,24 +101,37 @@ void display(GLFWwindow* window, double currentTime) {
     pMat=glm::perspective(utils::degToRad(60),aspect,0.1f,1000.f);
 
     vMat=glm::translate(glm::mat4(1.0f),glm::vec3{camera.x,camera.y,camera.z});
-    mMat=glm::translate(glm::mat4(1.0f),cubeLoc);
-    mvMat=vMat*mMat;
-
-    glUniformMatrix4fv(mvLoc,1,GL_FALSE,glm::value_ptr(mvMat));
-    glUniformMatrix4fv(projLoc,1,GL_FALSE,glm::value_ptr(pMat));
+    transforms.push(vMat);
     
-    glBindBuffer(GL_ARRAY_BUFFER,vbo[0]);
-    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0);
-    glEnableVertexAttribArray(0);
-    glDrawArrays(GL_TRIANGLES,0,36);
-
-    mMat=glm::translate(glm::mat4(1.0f),pyramidLoc);
-    mvMat=vMat*mMat;
-    glUniformMatrix4fv(mvLoc,1,GL_FALSE,glm::value_ptr(mvMat));
-    glUniformMatrix4fv(projLoc,1,GL_FALSE,glm::value_ptr(pMat));
-    glBindBuffer(GL_ARRAY_BUFFER,vbo[1]);
-    glVertexAttribPointer(0,3,GL_FLOAT,GL_FALSE,0,0);
-    glDrawArrays(GL_TRIANGLES,0,18);
+    mMat=glm::translate(transforms.top(),{0.f,0.f,0.f});
+    transforms.push(mMat);
+    mMat=glm::rotate(mMat,float(utils::degToRad(90)*currentTime),{0.f,1.f,0.f});
+    mMat=glm::rotate(mMat,float(utils::degToRad(12)),{0.f,0.f,1.f});
+    DrawSquarePyramid();
+    mMat=glm::translate(transforms.top(),{0.f,0.f,0.f});
+    mMat=glm::rotate(mMat,float(utils::degToRad(90)*currentTime),{0.f,1.f,0.f});
+    mMat=glm::rotate(mMat,float(utils::degToRad(192)),{0.f,0.f,1.f});
+    mMat=glm::translate(mMat,{0.f,2.f,0.f});
+    mMat=glm::rotate(mMat,float(utils::degToRad(270)),{0.f,1.f,0.f});
+    DrawSquarePyramid();
+
+    mMat=glm::translate(transforms.top(),{sin(currentTime*0.5)*6,sin(currentTime*0.5)*0.8-1,cos(currentTime*0.5)*6});
+    transforms.push(mMat);
+    mMat=glm::rotate(mMat,float(utils::degToRad(24)-28),{0,0,1});
+    mMat=glm::rotate(mMat,float(utils::degToRad(24)*currentTime+28),{0,1,0});
+    DrawCube();
+
+    mMat=glm::rotate(transforms.top(),utils::degToRad(90),{1,0,0});
+    mMat=glm::translate(mMat,{sin(currentTime*3)*3,0,cos(currentTime*3)*3});
+    mMat=glm::scale(mMat,{0.3,0.3,0.3});
+    mMat=glm::rotate(mMat,float(-utils::degToRad(220)*currentTime+4),{0,1,0});
+    DrawCube();
+
+    mMat=glm::rotate(transforms.top(),utils::degToRad(90),{1,1,0});
+    mMat=glm::translate(mMat,{sin(currentTime*3)*3,0,cos(currentTime*3)*3});
+    mMat=glm::scale(mMat,{0.3,0.3,0.3});
+    mMat=glm::rotate(mMat,float(utils::degToRad(120)*currentTime),{0,1,0});
+    DrawCube();
 }
 
 int main(void) {