Implement alpha blending

cw 6/shaders/shader_tex.frag

@@ -11,9 +11,11 @@ in float visibility;
 void main()
 {
 	vec2 modifiedTexCoord = vec2(interpTexCoord.x, 1.0 - interpTexCoord.y); // Poprawka dla tekstur Ziemi, ktore bez tego wyswietlaja sie 'do gory nogami'
-	vec3 color = texture2D(textureSampler, modifiedTexCoord).rgb;
+	vec4 rgba = texture2D(textureSampler, modifiedTexCoord).rgba;
+	if(rgba.a < 0.1) discard; // don't render the pixel if it's transparent
+
 	vec3 normal = normalize(interpNormal);
 	float diffuse = max(dot(normal, -lightDir), 0.0);
-	gl_FragColor = vec4(color * diffuse, 1.0);
+	gl_FragColor = rgba * diffuse;
 	gl_FragColor = mix(vec4(skyColor, 1.0), gl_FragColor, visibility);
 }

cw 6/src/main_6_1.cpp

@@ -56,6 +56,7 @@ GLuint textureSecondFish;
 GLuint textureThirdFish;
 GLuint textureSeaTurtle;
 GLuint textureCrab;
+GLuint bubbleTexture;
 
 void keyboard(unsigned char key, int x, int y)
 {
@@ -143,6 +144,15 @@ void drawObjectTexture(Core::RenderContext context, glm::mat4 modelMatrix, GLuin
 
 	glUseProgram(0);
 }
+
+void drawTranslucentObjects() {
+	glEnable(GL_BLEND); // enable blending
+
+	drawObjectTexture(sphereContext, glm::translate(glm::vec3(0, 5, 0)) * glm::scale(glm::vec3(5.0f, 5.0f, 5.0f)), bubbleTexture);
+
+	glDisable(GL_BLEND); // disable blending
+}
+
 void renderScene()
 {
 	// Aktualizacja macierzy widoku i rzutowania
@@ -150,7 +160,7 @@ void renderScene()
 	perspectiveMatrix = Core::createPerspectiveMatrix();
 
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-	glClearColor(0.0f, 0.1f, 0.3f, 1.0f);
+	glClearColor(skyColor.x, skyColor.y, skyColor.z, 1.0f);
 
 	float time = glutGet(GLUT_ELAPSED_TIME) / 1000.f;
 
@@ -174,6 +184,8 @@ void renderScene()
 	drawObjectColor(coralContext, glm::translate(glm::vec3(0, -14, 8)) * glm::rotate(glm::radians(270.f), glm::vec3(1, 0, 0)) * glm::scale(glm::vec3(0.1f)), glm::vec3(0.85f, 0.0255f, 0.6027f));
 	drawObjectColor(gorgonianCoralContext, glm::translate(glm::vec3(0, -14, 16)) * glm::rotate(glm::radians(270.f), glm::vec3(1, 0, 0)) * glm::scale(glm::vec3(0.07f)), glm::vec3(0.f, 1.f, 0.f));
 
+	drawTranslucentObjects();
+
 	glutSwapBuffers();
 }
 
@@ -194,8 +206,11 @@ void init()
 {
 	srand(time(0));
 	glEnable(GL_DEPTH_TEST);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
 	programColor = shaderLoader.CreateProgram("shaders/shader_color.vert", "shaders/shader_color.frag");
 	programTexture = shaderLoader.CreateProgram("shaders/shader_tex.vert", "shaders/shader_tex.frag");
+	loadModelToContext("models/sphere.obj", sphereContext);
 	loadModelToContext("models/ship.obj", shipContext);
 	loadModelToContext("models/seafloor.obj", seafloorContext);
 	loadModelToContext("models/skybox.obj", skyboxContext);
@@ -207,6 +222,7 @@ void init()
 	loadModelToContext("models/coral_tree.obj", coralTreeContext);
 	loadModelToContext("models/coral.obj", coralContext);
 	loadModelToContext("models/gorgonian_coral.obj", gorgonianCoralContext);
+	bubbleTexture = Core::LoadTexture("textures/bubble.png");
 	textureSkybox = Core::LoadTexture("textures/skybox.png");
 	textureFirstFish = Core::LoadTexture("textures/first_fish.png");
 	textureSecondFish = Core::LoadTexture("textures/second_fish.png");