//This is my orthographic projection window with two viewports, one looking down the x and one down the z axis.
void renderAxis() {
vec3 position;
glClearColor(0.4f, 0.4f, 0.4f, 0.0f);
glClearDepth(1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUseProgram(globals.program2);
//left side X-axis
glViewport( (int)(.1*globals.windowHalfWidth2), (int)(.1*globals.windowHeight2), (int)(.8*globals.windowHalfWidth2), (int)(.8*globals.windowHeight2) ); //Question
//set view matrix with camera looking down x-axis
glUniformMatrix4fv(globals.viewUniform2, 1, GL_FALSE, glm::value_ptr(globals.viewX));
//draw ships, save time and only draw one row, since in ortho proj we don't see anything behind since it's a parallel proj
float coord[] = { -60.0f, -20.0f, 20.0f, 60.0f };
for(int i = 0; i < 4; i++) {
position = vec3( 20.0f, 0.0f, coord[i]);
ship.render(position, globals.vaoSphere2, globals.vaoCylinder2, globals.worldUniform2, globals.fragColorUniform2);
}
//draw sphere
glPolygonMode(GL_FRONT, GL_LINE);
glPolygonMode(GL_BACK, GL_LINE);
//update uniforms
mat4 temp(1.0f);
temp[3] = vec4(-80.0f, 0.0f, 0.0f, 1.0f);
glUniformMatrix4fv(globals.worldUniform2, 1, GL_FALSE, glm::value_ptr(temp));
vec4 color(1.0f, 1.0f, 1.0f, 1.0f);
glUniform4fv(globals.fragColorUniform2, 1, glm::value_ptr(color));
glBindVertexArray(globals.vaoSphere3);
glDrawElements(GL_TRIANGLES, globals.elementSphere3.size(), GL_UNSIGNED_SHORT, 0);
//reset this so other objects get filled in
glPolygonMode(GL_FRONT, GL_FILL);
glPolygonMode(GL_BACK, GL_FILL);
glBindVertexArray(0);
//right side Z-axis
glViewport( (int)(.1*globals.windowHalfWidth2 + globals.windowHalfWidth2), (int)(.1*globals.windowHeight2), (int)(.8*globals.windowHalfWidth2), (int)(.8*globals.windowHeight2));
glUniformMatrix4fv(globals.viewUniform2, 1, GL_FALSE, glm::value_ptr(globals.viewZ));
for(int i = 0; i < 4; i++) {
position = vec3( coord[i], 0.0f, 20.0f);
ship.render(position, globals.vaoSphere1, globals.vaoCylinder1, globals.worldUniform1, globals.fragColorUniform1);
}
//draw sphere
glPolygonMode(GL_FRONT, GL_LINE);
glPolygonMode(GL_BACK, GL_LINE);
//update uniforms
temp[3] = vec4(0.0f, 0.0f, -80.0f, 1.0f);
glUniformMatrix4fv(globals.worldUniform2, 1, GL_FALSE, glm::value_ptr(temp));
color = vec4(1.0f, 1.0f, 1.0f, 1.0f);
glUniform4fv(globals.fragColorUniform2, 1, glm::value_ptr(color));
glBindVertexArray(globals.vaoSphere3);
glDrawElements(GL_TRIANGLES, globals.elementSphere3.size(), GL_UNSIGNED_SHORT, 0);
glPolygonMode(GL_FRONT, GL_FILL);
glPolygonMode(GL_BACK, GL_FILL);
glBindVertexArray(0);
glUseProgram(0);
//draw frustum
glUseProgram(globals.program3);
glBindVertexArray(globals.vaoFrustum);
//set uniforms that will be used by the frustum shader program
mat4 world(1.0f);
glUniformMatrix4fv(globals.worldUniform, 1, GL_FALSE, glm::value_ptr(world)); //world
glUniformMatrix4fv(globals.viewUniform, 1, GL_FALSE, glm::value_ptr(globals.viewX)); //view
glUniformMatrix4fv(globals.projUniform, 1, GL_FALSE, glm::value_ptr(globals.orthoProj)); //proj
mat4 inverse = CalcViewMatrix(globals.camera.camPosition, globals.camera.camTarget, globals.camera.upDirection);
inverse = glm::inverse(inverse);
glUniformMatrix4fv(globals.inverseViewUniform, 1, GL_FALSE, glm::value_ptr(inverse)); // view inverse
inverse = glm::inverse(globals.perspProj);
glUniformMatrix4fv(globals.inverseProjUniform, 1, GL_FALSE, glm::value_ptr(inverse)); //proj inverse
//use same two viewports for drawing the frustum. I do this separately because I have a particular shader program and didn't want to switch back and forth.
//left side X-axis
glViewport( (int)(.1*globals.windowHalfWidth2), (int)(.1*globals.windowHeight2), (int)(.8*globals.windowHalfWidth2), (int)(.8*globals.windowHeight2) );
glPointSize(10.0f);
glDrawElements(GL_LINES, 48, GL_UNSIGNED_SHORT, (GLvoid*)0);
//right side Z-axis
glUniformMatrix4fv(globals.viewUniform, 1, GL_FALSE, glm::value_ptr(globals.viewZ)); //view
glViewport( (int)(.1*globals.windowHalfWidth2 + globals.windowHalfWidth2), (int)(.1*globals.windowHeight2), (int)(.8*globals.windowHalfWidth2), (int)(.8*globals.windowHeight2));
glDrawElements(GL_LINES, 48, GL_UNSIGNED_SHORT, (GLvoid*)0);
glBindVertexArray(0);
glUseProgram(0);
//draw text
glViewport(0, 0, 400, 400);
const unsigned char string1[] = "Options: w - wireframe mode, m - antialiasing, t - textures";
vec3 temp2(-80.0f, -30.0f, 0.0f);
drawText(string1, temp2);
const unsigned char string2[] = "X - A X I S";
temp2 = vec3(-80.0f, -40.0f, 0.0f);
drawText(string2, temp2);
glViewport(700, 0, 800, 400);
const unsigned char string3[] = "Z - A X I S";
temp2 = vec3(-80.0f, -40.0f, 0.0f);
drawText(string3, temp2);
glutSwapBuffers();
glutPostRedisplay();
}
//This is my perspective window render fuction
void renderFPS() {
//enable options
//msaa
if(globals.msaaEnable) {
glEnable(GL_MULTISAMPLE_ARB);
} else {
glDisable(GL_MULTISAMPLE_ARB);
}
//wireframe mode
if(globals.wireframeEnable) {
glPolygonMode(GL_FRONT, GL_LINE);
glPolygonMode(GL_BACK, GL_LINE);
} else {
glPolygonMode(GL_FRONT, GL_FILL);
glPolygonMode(GL_BACK, GL_FILL);
}
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClearDepth(1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//get current view matrix from camera class
mat4 view = CalcViewMatrix(globals.camera.camPosition, globals.camera.camTarget, globals.camera.upDirection);
glUseProgram(globals.program1);
//get view matrix from camera
glUniformMatrix4fv(globals.viewUniform1, 1, GL_FALSE, glm::value_ptr(view));
//for this project, each ship is going to be the same, could either add method or parameter to pass in a "world" matrix
//or a scale/rotation matrix to alter each ship individually
//draw ships passing in the postion it should be placed
float coord[] = { -60.0f, -20.0f, 20.0f, 60.0f }; //used to place ships
vec3 position;
for(int i = 0; i < 4; i++) {
position = vec3( coord[i], 0.0f, -60.0f);
ship.render(position, globals.vaoSphere1, globals.vaoCylinder1, globals.worldUniform1, globals.fragColorUniform1);
position = vec3( coord[i], 0.0f, -20.0f);
ship.render(position, globals.vaoSphere1, globals.vaoCylinder1, globals.worldUniform1, globals.fragColorUniform1);
position = vec3( coord[i], 0.0f, 20.0f);
ship.render(position, globals.vaoSphere1, globals.vaoCylinder1, globals.worldUniform1, globals.fragColorUniform1);
position = vec3( coord[i], 0.0f, 60.0f);
ship.render(position, globals.vaoSphere1, globals.vaoCylinder1, globals.worldUniform1, globals.fragColorUniform1);
}
glUseProgram(0);
//I have this as an option since for this project we wanted to demonstrate the frustum and so I can't see all of the textured floor so I can
//turn it on and off.
if(globals.textureOn) {
//draw textured floor
glUseProgram(globals.programT);
glBindVertexArray(globals.vaoT);
glUniformMatrix4fv(globals.viewTUniform, 1, GL_FALSE, glm::value_ptr(view)); //view
mat4 world(1.0f);
world[3] = vec4(0.0f, -19.0f, 0.0f, 1.0f); //translate
world[0].x = world[2].z = 100.0f; //scale
glUniformMatrix4fv(globals.worldTUniform, 1, GL_FALSE, glm::value_ptr(world));
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, globals.texture);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, (GLubyte*)0);
glBindVertexArray(0);
glUseProgram(0);
}
//draw text
glViewport(0, 0, 400, 400); //do this so that text gets rendered to same area in window and doesn't change due to resizing
const unsigned char string1[] = "Options: w - wireframe mode, m - antialiasing, t - textures";
vec3 temp(-80.0f, -30.0f, 0.0f);
drawText(string1, temp);
const unsigned char string2[] = "PERSPECTIVE VIEW";
temp = vec3(-80.0f, -40.0f, 0.0f);
drawText(string2, temp);
glViewport(0, 0, globals.windowWidth1, globals.windowHeight1); //reset viewport back to entire screen
glutSwapBuffers();
glutPostRedisplay();
}
