Stencil Testing

SeriousSamV · Feb 27, 2017 · 05d54fe · 05d54fe
1 parent 93b0afc
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diff --git a/16/16.fragment.glsl b/16/16.fragment.glsl
@@ -0,0 +1,8 @@
+#version 330 core
+
+out vec4 outColor;
+
+void main()
+{
+	outColor = vec4(0.04, 0.28, 0.26, 1.0);
+}
diff --git a/16/16.vertex.glsl b/16/16.vertex.glsl
@@ -0,0 +1,15 @@
+#version 330 core
+layout(location = 0) in vec3 position;
+layout(location = 1) in vec2 texCoords;
+
+out vec2 TexCoords;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+	gl_Position = projection * view * model * vec4(position, 1.0f);
+	TexCoords = texCoords;
+}
diff --git a/16/stencil_testing_example_app.cpp b/16/stencil_testing_example_app.cpp
@@ -0,0 +1,251 @@
+#include "c:/Users/samuel vishesh paul/documents/visual studio 2015/Projects/OpenGL Playground/OpenGL Playground/stdafx.h"
+
+class StencilTestingApp : public mylib::App
+{
+public:
+	std::vector<GLfloat> cubeVertices = {
+		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
+		0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
+		0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+		0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
+
+		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+		0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+		0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
+		0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
+		-0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
+		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+
+		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+		-0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+
+		0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+		0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+		0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+		0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+		0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+		0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+
+		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+		0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
+		0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+		0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
+		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
+		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
+
+		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
+		0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
+		0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+		0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
+		-0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
+		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f
+	};
+	std::vector<GLfloat> planeVertices = {
+		// Positions        // Texture Coords (note we set these higher 
+		// than 1 that together with GL_REPEAT as 
+		// texture wrapping mode will cause the 
+		// floor texture to repeat)
+		5.0f,  -0.5f,  5.0f,  2.0f, 0.0f,
+		-5.0f, -0.5f,  5.0f,  0.0f, 0.0f,
+		-5.0f, -0.5f, -5.0f,  0.0f, 2.0f,
+
+		5.0f,  -0.5f,  5.0f,  2.0f, 0.0f,
+		-5.0f, -0.5f, -5.0f,  0.0f, 2.0f,
+		5.0f,  -0.5f, -5.0f,  2.0f, 2.0f
+	};
+	GLuint VAO[2]{ 0 }, VBO[2]{ 0 };
+	GLuint &cubeVAO = VAO[0], &planeVAO = VAO[1],
+		&cubeVBO = VBO[0], &planeVBO = VBO[1];
+	mylib::Shader shader, singleColorShader;
+	mylib::Shader *activeShader{ nullptr };
+	GLuint cubeTex, floorTex;
+	mylib::Camera camera;
+	mylib::CameraController cameraController;
+	glm::mat4 model, view, projection;
+
+	int option{ 0 };
+
+	StencilTestingApp(mylib::Window&& window) : mylib::App(std::move(window))
+	{}
+
+	void startup() override
+	{
+		singleColorShader = mylib::Shader({
+			std::make_pair(
+				"C:/Users/Samuel Vishesh Paul/Documents/GitHub/My-Jolly-journey/16/16.vertex.glsl",
+				GL_VERTEX_SHADER),
+			std::make_pair(
+				"C:/Users/Samuel Vishesh Paul/Documents/GitHub/My-Jolly-journey/16/16.fragment.glsl",
+				GL_FRAGMENT_SHADER)
+		});
+		shader = mylib::Shader({
+			std::make_pair(
+				"C:/Users/Samuel Vishesh Paul/Documents/GitHub/My-Jolly-journey/15/15.vertex.glsl",
+				GL_VERTEX_SHADER),
+			std::make_pair(
+				"C:/Users/Samuel Vishesh Paul/Documents/GitHub/My-Jolly-journey/15/15.fragment.glsl",
+				GL_FRAGMENT_SHADER)
+		});
+
+		glGenVertexArrays(2, VAO);
+		glGenBuffers(2, VBO);
+		glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+		glBufferData(GL_ARRAY_BUFFER,
+			cubeVertices.size() * sizeof(*(cubeVertices.data())),
+			cubeVertices.data(),
+			GL_STATIC_DRAW);
+		glBindBuffer(GL_ARRAY_BUFFER, planeVBO);
+		glBufferData(GL_ARRAY_BUFFER,
+			planeVertices.size() * sizeof(*(planeVertices.data())),
+			planeVertices.data(),
+			GL_STATIC_DRAW);
+
+		// cube
+		glBindVertexArray(cubeVAO);
+		glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+		glEnableVertexAttribArray(0);
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,
+			5 * sizeof(*(cubeVertices.data())),
+			ML_BUFFER_OFFSET(0));
+		glEnableVertexAttribArray(1);
+		glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE,
+			5 * sizeof(*(cubeVertices.data())),
+			ML_BUFFER_OFFSET(3 * sizeof(*(cubeVertices.data()))));
+		glBindVertexArray(0);
+		// plane
+		glBindVertexArray(planeVAO);
+		glBindBuffer(GL_ARRAY_BUFFER, planeVBO);
+		glEnableVertexAttribArray(0);
+		glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE,
+			5 * sizeof(*(planeVertices.data())),
+			ML_BUFFER_OFFSET(0));
+		glEnableVertexAttribArray(1);
+		glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE,
+			5 * sizeof(*(planeVertices.data())),
+			ML_BUFFER_OFFSET(3 * sizeof(*(planeVertices.data()))));
+		glBindVertexArray(0);
+
+		cubeTex = mylib::loadTexture(
+			"C:/Users/Samuel Vishesh Paul/Documents/GitHub/LearnOpenGL/resources/textures/marble.jpg");
+		floorTex = mylib::loadTexture(
+			"C:/Users/Samuel Vishesh Paul/Documents/GitHub/LearnOpenGL/resources/textures/metal.png");
+
+		camera = mylib::Camera(
+			glm::vec3(0.0f, 0.0f, 3.0f),	// cameraPos
+			glm::vec3(0.0f, 1.0f, 0.0f));	// cmaeraUp
+		cameraController = mylib::CameraController(
+			&camera, &window);
+
+		glEnable(GL_DEPTH_TEST);
+		glEnable(GL_STENCIL_TEST);
+		glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
+		//glStencilOp(GL_KEEP, GL_REPLACE, GL_REPLACE);
+	}
+
+	void update(double time) override
+	{
+		cameraController.update(cameraController, time);
+		view = cameraController.camera->getViewMatrix();
+		projection = glm::perspective(
+			camera.zoom,
+			static_cast<GLfloat>(window.width) / window.height,
+			0.1f, 100.0f);
+
+		activeShader = &shader;
+		activeShader->use();
+		glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "projection"),
+			1, GL_FALSE, glm::value_ptr(projection));
+		glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "view"),
+			1, GL_FALSE, glm::value_ptr(view));
+		activeShader = &singleColorShader;
+		activeShader->use();
+		glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "projection"),
+			1, GL_FALSE, glm::value_ptr(projection));
+		glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "view"),
+			1, GL_FALSE, glm::value_ptr(view));
+	}
+
+	void render() override
+	{
+		glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+		// Floor
+		//	Draw floor as normal, we only care about the containers. 
+		//	The floor should NOT fill the stencil buffer so we set its mask to 0x00
+		glStencilMask(0x00);
+		activeShader = &shader;
+		activeShader->use();
+		glBindVertexArray(planeVAO);
+		glBindTexture(GL_TEXTURE_2D, floorTex);
+		model = glm::translate(glm::mat4(), glm::vec3(0));
+		glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "model"),
+			1, GL_FALSE, glm::value_ptr(model));
+		glDrawArrays(GL_TRIANGLES, 0, 6);
+		glBindVertexArray(0);
+		// clear stencil buffer to 0s and for boxes we update the stencil buffer to 1 for 
+		// each fragment drawn
+		// // 1st. Render pass, draw objects as normal, filling the stencil buffer
+		glStencilFunc(GL_ALWAYS, 1, 0xFF); // All fragments should update the stencil buffer
+		glStencilMask(0xFF); // Enable writing to the stencil buffer
+		// draw boxes
+		{
+			activeShader->use();
+			glBindVertexArray(cubeVAO);
+			glBindTexture(GL_TEXTURE_2D, cubeTex);
+			model = glm::translate(glm::mat4(), glm::vec3(-1.0f, 0.0f + 0.0001f, -1.0f));
+			glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "model"),
+				1, GL_FALSE, glm::value_ptr(model));
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+			model = glm::translate(glm::mat4(), glm::vec3(2.0f, 0.0f + 0.0001f, 0.0f));
+			glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "model"),
+				1, GL_FALSE, glm::value_ptr(model));
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+			glBindVertexArray(0);
+		}
+		// Stencil Render Pass
+		//	2nd. Render pass, now draw slightly scaled versions of the objects, 
+		//	this time disabling stencil writing.
+		//	Because stencil buffer is now filled with several 1s. 
+		//	The parts of the buffer that are 1 are now not drawn, thus only drawing 
+		//	the objects' size differences, making it look like borders.
+		glStencilFunc(GL_NOTEQUAL, 1, 0xFF);
+		glStencilMask(0x00);	// disable writing to the stencil buffer
+		glDisable(GL_DEPTH_TEST);
+		// draw border boxes
+		{
+			activeShader = &singleColorShader;
+			activeShader->use();
+			glBindVertexArray(cubeVAO);
+			glBindTexture(GL_TEXTURE_2D, cubeTex);
+			model = glm::translate(glm::mat4(), glm::vec3(-1.0f, 0.0f + 0.0001f, -1.0f));
+			model = glm::scale(model, glm::vec3(1.1));
+			glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "model"),
+				1, GL_FALSE, glm::value_ptr(model));
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+			model = glm::translate(glm::mat4(), glm::vec3(2.0f, 0.0f + 0.0001f, 0.0f));
+			model = glm::scale(model, glm::vec3(1.1));
+			glUniformMatrix4fv(glGetUniformLocation(activeShader->program, "model"),
+				1, GL_FALSE, glm::value_ptr(model));
+			glDrawArrays(GL_TRIANGLES, 0, 36);
+			glBindVertexArray(0);
+		}
+		glStencilMask(0xFF);
+		glEnable(GL_DEPTH_TEST);
+	}
+
+	void shutdown() override
+	{
+		glDeleteVertexArrays(2, VAO);
+		glDeleteBuffers(2, VBO);
+	}
+
+private:
+
+};