Add belly to triangle
[opengl.git] / main.cpp
index 99312d384ed00ea36ff83640f32d5621201704fd..67c3ebeeae849482ba27d7ea0f9be79cd76c70f7 100644 (file)
--- a/main.cpp
+++ b/main.cpp
 
 using namespace std;
 
-GLuint* vaos;
-GLuint progId;
+GLuint pyramidVao, lightVao;
+GLuint gradientProgId, solidProgId;
 glm::vec3 camPos   = glm::vec3(0.0f, 0.0f,  -5.0f);
 glm::vec3 camFront = glm::vec3(0.0f, 0.0f, 1.0f);
 glm::vec3 camUp    = glm::vec3(0.0f, 1.0f,  0.0f);
 float yaw = 1.57, pitch = 0;
 bool doScale, doRotate, doTranslate;
 
-void display() {
-       glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
-       glUseProgram(progId);
-       glBindVertexArray(vaos[0]);
-       for (int i = 0; i < 100; i++) {
-
+void setProjectionAndViewUniforms(GLuint progId) {
        GLuint projId = glGetUniformLocation(progId, "projection");
        glm::mat4 proj = glm::perspective(glm::radians(45.f), 1.33f, 0.01f, 10000.f);
        glUniformMatrix4fv(projId, 1, GL_FALSE, glm::value_ptr(proj));
@@ -40,12 +35,42 @@ void display() {
        GLuint viewId = glGetUniformLocation(progId, "view");
        glm::mat4 view = glm::lookAt(camPos, camPos + camFront, camUp);
        glUniformMatrix4fv(viewId, 1, GL_FALSE, glm::value_ptr(view));
+}
+
+void drawLight(float d, glm::vec3 lightPos) {
+       glUseProgram(solidProgId);
+       glBindVertexArray(lightVao);
+       setProjectionAndViewUniforms(solidProgId);
+       glm::mat4 model = glm::translate(glm::mat4(1.f), lightPos);
+       model = glm::scale(model, glm::vec3(0.2));
+       GLuint modelId = glGetUniformLocation(solidProgId, "model");
+       glUniformMatrix4fv(modelId, 1, GL_FALSE, glm::value_ptr(model));
+
+       GLuint colorLoc = glGetUniformLocation(solidProgId, "color");
+       glm::vec3 color = glm::vec3(1, 1, 1);
+       glUniform3fv(colorLoc, 1, glm::value_ptr(color));
+               
+       glDrawArrays(GL_TRIANGLES, 0, 36);
+};
+
+void drawPyramids(float d, glm::vec3 lightPos) {
+       glUseProgram(gradientProgId);
+       glBindVertexArray(pyramidVao);
+       setProjectionAndViewUniforms(gradientProgId);
+
+       GLuint lightPosLoc = glGetUniformLocation(gradientProgId, "lightPos");
+       glUniform3fv(lightPosLoc, 1, glm::value_ptr(lightPos));
+       
+       GLuint viewPosLoc = glGetUniformLocation(gradientProgId, "viewPos");
+       glUniform3fv(viewPosLoc, 1, glm::value_ptr(camPos));
+
+       GLuint modelId = glGetUniformLocation(gradientProgId, "model");
+
+       for (int i = 0; i < 10; i++) {
 
-               GLuint modelId = glGetUniformLocation(progId, "model");
                glm::mat4 model = glm::mat4(1.f);
 
-               float d = (float)glutGet(GLUT_ELAPSED_TIME) * 0.001f;
-               model = glm::translate(model, glm::vec3(sin(i * 30) * 10, cos(i * 30) * 10, i * 2));
+               model = glm::translate(model, glm::vec3(sin(i * 30) * 10, 0, i * 2 - 10));
                
                if (doRotate) {
                        model = glm::rotate(model, d * glm::radians(30.f), glm::vec3(0.f, 1.f, 0.f));
@@ -61,8 +86,20 @@ void display() {
 
                glUniformMatrix4fv(modelId, 1, GL_FALSE, glm::value_ptr(model));
                
-               glDrawArrays(GL_TRIANGLES, 0, 12);
+               glDrawArrays(GL_TRIANGLES, 0, 18);
        }
+
+};
+
+void display() {
+       glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
+       float d = (float)glutGet(GLUT_ELAPSED_TIME) * 0.001f;
+
+       glm::vec3 lightPos = glm::vec3(sin(d) * 10, 0, cos(d) * 10);
+
+       drawPyramids(d, lightPos);
+       drawLight(d, lightPos);
+
        glutSwapBuffers();
 }
 
@@ -114,7 +151,7 @@ GLuint compileShaders(char* vertexShader, char* fragmentShader) {
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
-GLuint setupBuffers(GLfloat* vertices, GLuint progId) {
+GLuint setupBuffers(glm::vec3* vertices, glm::vec3* normals, GLuint progId) {
 
        GLfloat colors[] = {
                0, 1, 0, 1,
@@ -129,12 +166,20 @@ GLuint setupBuffers(GLfloat* vertices, GLuint progId) {
                1, 0, 0, 1,
                0, 0, 1, 1,
 
+               0, 1, 0, 1,
+               1, 0, 0, 1,
+               0, 0, 1, 1,
+
+               0, 1, 0, 1,
+               1, 0, 0, 1,
+               0, 0, 1, 1,
+               
                0, 1, 0, 1,
                1, 0, 0, 1,
                0, 0, 1, 1
        };
 
-       GLuint numVerts = 12;
+       GLuint numVerts = 18;
 
        GLuint vbo;
        glGenBuffers(1, &vbo);
@@ -144,26 +189,118 @@ GLuint setupBuffers(GLfloat* vertices, GLuint progId) {
 
        GLuint posId = glGetAttribLocation(progId, "vPosition");
        GLuint colorId = glGetAttribLocation(progId, "vColor");
+       GLuint normalLoc = glGetAttribLocation(progId, "vNormal");
 
        GLuint vertsLen = numVerts * 3 * sizeof(GLfloat);
        GLuint colorsLen = numVerts * 4 * sizeof(GLfloat);
+       GLuint normalLen = numVerts * 3 * sizeof(GLfloat);
 
        glBindBuffer(GL_ARRAY_BUFFER, vbo);
-       glBufferData(GL_ARRAY_BUFFER, vertsLen + colorsLen, NULL, GL_STATIC_DRAW);
+       glBufferData(GL_ARRAY_BUFFER, vertsLen + colorsLen + normalLen, NULL, GL_STATIC_DRAW);
 
-       glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, vertices);
+       glBufferSubData(GL_ARRAY_BUFFER, 0, vertsLen, glm::value_ptr(vertices[0]));
        glBufferSubData(GL_ARRAY_BUFFER, vertsLen, colorsLen, colors);
+       glBufferSubData(GL_ARRAY_BUFFER, vertsLen + colorsLen, normalLen, glm::value_ptr(normals[0]));
        
        glBindVertexArray(vao);
+
        glEnableVertexAttribArray(posId);
        glVertexAttribPointer(posId, 3, GL_FLOAT, GL_FALSE, 0, 0);
 
        glEnableVertexAttribArray(colorId);
-       glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(numVerts * 3 * sizeof(GLfloat)));
+       glVertexAttribPointer(colorId, 4, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen));
+
+       glEnableVertexAttribArray(normalLoc);
+       glVertexAttribPointer(normalLoc, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(vertsLen + colorsLen));
 
        return vao;
 }
 
+vector<glm::vec3> quadToTriangles(glm::vec3 *quads) {
+       vector<glm::vec3> triangles(6);
+       triangles[0] = quads[0];
+       triangles[1] = quads[1];
+       triangles[2] = quads[2];
+       triangles[3] = quads[2];
+       triangles[4] = quads[3];
+       triangles[5] = quads[0];
+       return triangles;
+}
+
+template <typename T>
+void append(vector<T> &a, vector<T> &b) {
+       a.insert(a.end(), b.begin(), b.end());
+};
+
+void setupLightBuffers(GLuint progId) {
+       vector<glm::vec3> vertices;
+       glm::vec3 front[] = {
+               glm::vec3(1, -1, -1),
+               glm::vec3(-1, -1, -1),
+               glm::vec3(-1, 1, -1),
+               glm::vec3(1, 1, -1)
+       };
+       vector<glm::vec3> frontTriangles = quadToTriangles(front);
+       append(vertices, frontTriangles);
+
+       glm::vec3 back[] = {
+               glm::vec3(1, 1, 1),
+               glm::vec3(-1, 1, 1),
+               glm::vec3(-1, -1, 1),
+               glm::vec3(1, -1, 1)
+       };
+       vector<glm::vec3> backQuads = quadToTriangles(back);
+       append(vertices, backQuads);
+
+       glm::vec3 top[] = {
+               glm::vec3(1, 1, -1),
+               glm::vec3(-1, 1, -1),
+               glm::vec3(-1, 1, 1),
+               glm::vec3(1, 1, 1)
+       };
+       vector<glm::vec3> topTriangles = quadToTriangles(top);
+       append(vertices, topTriangles);
+
+       glm::vec3 bottom[] = {
+               glm::vec3(1, -1, 1),
+               glm::vec3(-1, -1, 1),
+               glm::vec3(-1, -1, -1),
+               glm::vec3(1, -1, -1)
+       };
+       vector<glm::vec3> bottomTriangles = quadToTriangles(bottom);
+       append(vertices, bottomTriangles);
+
+       glm::vec3 left[] = {
+               glm::vec3(-1, 1, 1),
+               glm::vec3(-1, 1, -1),
+               glm::vec3(-1, -1, -1),
+               glm::vec3(-1, -1, 1)
+       };
+       vector<glm::vec3> leftTriangles = quadToTriangles(left);
+       append(vertices, leftTriangles);
+
+       glm::vec3 right[] = {
+               glm::vec3(1, 1, -1),
+               glm::vec3(1, 1, 1),
+               glm::vec3(1, -1, 1),
+               glm::vec3(1, -1, -1)
+       };
+       vector<glm::vec3> rightTriangles = quadToTriangles(right);
+       append(vertices, rightTriangles);
+       GLuint verticesSize = 36 * 3 * sizeof(GLfloat);
+
+       glGenVertexArrays(1, &lightVao);
+       GLuint vbo;
+       glBindVertexArray(lightVao);
+       glGenBuffers(1, &vbo);
+       glBindBuffer(GL_ARRAY_BUFFER, vbo);
+       glBufferData(GL_ARRAY_BUFFER, verticesSize, NULL, GL_STATIC_DRAW);
+       glBufferSubData(GL_ARRAY_BUFFER, 0, verticesSize, glm::value_ptr(vertices[0]));
+       GLuint posLoc = glGetAttribLocation(progId, "vPosition");
+       glEnableVertexAttribArray(posLoc);
+       glVertexAttribPointer(posLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
+}
+
 void validateProgram(GLuint progId) {
        glValidateProgram(progId);
        
@@ -178,33 +315,57 @@ void validateProgram(GLuint progId) {
 }
 
 void init() {
-       GLfloat vertices[9*4] = {
-               -1.0f, -1.0f, -1.0f,
-               1.0f, -1.0f, -1.0f,
-               0.0f, 1.0f, 0.0f,
-
-               -1.0f, -1.0f, 1.0f,
-               1.0f, -1.0f, 1.0f,
-               0.0f, 1.0f, 0.0f,
-
-               -1.0f, -1.0f, -1.0f,
-               -1.0f, -1.0f, 1.0f,
-               0.0f, 1.0f, 0.0f,
-
-               1.0f, -1.0f, -1.0f,
-               1.0f, -1.0f, 1.0f,
-               0.0f, 1.0f, 0.0f
-
+       glm::vec3 vertices[18] = {
+               glm::vec3(0.0f, 1.0f, 0.0f),
+               glm::vec3(1.0f, -1.0f, -1.0f),
+               glm::vec3(-1.0f, -1.0f, -1.0f),
+
+               glm::vec3(0.0f, 1.0f, 0.0f),
+               glm::vec3(-1.0f, -1.0f, 1.0f),
+               glm::vec3(1.0f, -1.0f, 1.0f),
+
+               glm::vec3(0.0f, 1.0f, 0.0f),
+               glm::vec3(-1.0f, -1.0f, -1.0f),
+               glm::vec3(-1.0f, -1.0f, 1.0f),
+
+               glm::vec3(0.0f, 1.0f, 0.0f),
+               glm::vec3(1.0f, -1.0f, 1.0f),
+               glm::vec3(1.0f, -1.0f, -1.0f),
+
+               glm::vec3(1, -1, 1),
+               glm::vec3(-1, -1, 1),
+               glm::vec3(-1, -1, -1),
+               glm::vec3(-1, -1, -1),
+               glm::vec3(1, -1, -1),
+               glm::vec3(1, -1, 1)
        };
 
-       vaos = new GLuint[2];
+       // work out the normals
+       glm::vec3 normals[18];
+       for (int i = 0; i < 6; i++) {
+               glm::vec3 a = vertices[i * 3];
+               glm::vec3 b = vertices[i * 3 + 1];
+               glm::vec3 c = vertices[i * 3 + 2];
+               glm::vec3 u = glm::normalize(a - c);
+               glm::vec3 v = glm::normalize(b - c);
+               glm::vec3 norm = glm::normalize(glm::cross(v, u));
+               for(int j = 0; j < 3; j++) {
+                       normals[i * 3 + j] = glm::vec3(norm);
+               }
+       }
+
+       gradientProgId = compileShaders((char*)"vertex.glsl", (char*)"fragment.glsl");
+       glUseProgram(gradientProgId);
+       pyramidVao = setupBuffers(vertices, normals, gradientProgId);
+       validateProgram(gradientProgId);
 
-       progId = compileShaders((char*)"vertex.glsl", (char*)"fragment.glsl");
-       glUseProgram(progId);
-       vaos[0] = setupBuffers(vertices, progId);
-       validateProgram(progId);
+       solidProgId = compileShaders((char*)"solidvertex.glsl", (char*)"solidfrag.glsl");
+       glUseProgram(solidProgId);
+       setupLightBuffers(solidProgId);
+       validateProgram(solidProgId);
 
        glEnable(GL_DEPTH_TEST); 
+       glEnable(GL_CULL_FACE); 
 }
 
 bool* keyStates = new bool[256];
@@ -242,7 +403,7 @@ void timer(int _) {
        camPos.y += ySpeed;
        camPos.z += zSpeed * sin(yaw) - xSpeed * cos(yaw);
        glutPostRedisplay();
-       glutTimerFunc(16, idle, 0);
+       glutTimerFunc(16, timer, 0);
 }
 
 int prevMouseX, prevMouseY;