build visualisation for lookAt and projection

src/main.c

@@ -15,17 +15,27 @@
 #define STATUS_INTERVAL 0.5
 #define PI 3.14159f
 
+GLFWwindow* window;
+
 GLuint program;
+GLuint originProgram;
+GLuint floorProgram;
 
 GLuint vertexArrayObject;
 
+GLuint originVAO;
+
 GLuint indexBuffer;
+GLuint lineIndexBuffer;
+GLuint floorIndexBuffer;
 
 GLuint initialWindowWidth = 800;
 GLuint initialWindowHeight = 600;
 
 GLfloat aspect;
-mat4 projectionMatrix;
+mat4 realProjectionMatrix;
+
+GLfloat currentHue = 0.0f;
 
 int frameCount = 0;
 struct timespec last_time, current_time;
@@ -77,19 +87,19 @@ void updateStatusDisplay() {
 		double fps = frameCount / elapsed;
 		frameCount = 0;
 		last_time = current_time;
-		printf("\rFPS: %.2f ", fps);
+		printf("\rFPS: %5.2f - currentValue: %5.2f", fps, currentHue);
 		fflush(stdout);
 	}
 }
 
 void recalculateProjectionMatrix() {
-	mat4BuildPerspective(projectionMatrix, 60 * M_PI / 180, aspect, 0.1, 10);
+	mat4BuildPerspective(realProjectionMatrix, 90 * M_PI / 180, aspect, 0.1, 50);
 	DEBUG("Recalculating Projection Matrix");
 }
 
 void init(void) {
 
-	INFO("Building Programs...");
+	INFO("Building main program...");
 	ProgramLinkResult linkResult = buildShaderProgram("src/shaders/vertex.glsl", "src/shaders/fragment.glsl");
 	if (!linkResult.success) {
 		FATAL("Failed to link Program");
@@ -98,6 +108,25 @@ void init(void) {
 
 	program = linkResult.program;
 
+
+	INFO("Building origin program...");
+	linkResult = buildShaderProgram("src/shaders/origin-vertex.glsl", "src/shaders/origin-fragment.glsl");
+	if (!linkResult.success) {
+		FATAL("Failed to link Program");
+		exit(1);
+	}
+
+	originProgram = linkResult.program;
+
+	INFO("Building floor program...");
+	linkResult = buildShaderProgram("src/shaders/floor-vertex.glsl", "src/shaders/floor-fragment.glsl");
+	if (!linkResult.success) {
+		FATAL("Failed to link Program");
+		exit(1);
+	}
+
+	floorProgram = linkResult.program;
+
 	INFO("Shader Program Done.");
 
 	// create triangle buffer
@@ -158,6 +187,32 @@ void init(void) {
 		7, 3, 6
 	};
 
+	GLuint lineIndices[] = {
+		0, 1,
+		0, 2,
+		0, 4,
+
+		1, 3,
+		1, 5,
+
+		2, 3,
+		2, 6,
+
+		3, 7,
+
+		4, 5,
+		4, 6,
+
+		5, 7,
+
+		6, 7
+	};
+
+	GLuint floorIndices[] = {
+		2, 3, 6,
+		3, 7, 6
+	};
+
 	DEBUG("Creating vertext buffer");
 	GLuint vertexBuffer;
 	glGenBuffers(1, &vertexBuffer);
@@ -181,24 +236,79 @@ void init(void) {
 		0 // start offset
 	);
 	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(
+		1, // shader location
+		3, // number of values to read
+		GL_FLOAT, // type of value
+		GL_FALSE, // if values are normalised
+		3 * sizeof(GLfloat), // stride - distance between vertices
+		0 // start offset
+	);
+	glEnableVertexAttribArray(1);
+
+	DEBUG("Creating index buffers");
+
 
-	DEBUG("Creating index buffer");
 	glGenBuffers(1, &indexBuffer);
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+
+
+	glGenBuffers(1, &lineIndexBuffer);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, lineIndexBuffer);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(lineIndices), lineIndices, GL_STATIC_DRAW);
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+
+
+	glGenBuffers(1, &floorIndexBuffer);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, floorIndexBuffer);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(floorIndices), floorIndices, GL_STATIC_DRAW);
+
+
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 	glBindVertexArray(0);
 
-	glClearColor(0.0f, 0.0f, 0.0f, 0.3f);
+
+	glClearColor(0.3f, 0.3f, 0.4f, 1.0f);
 	glViewport(0, 0, initialWindowWidth, initialWindowHeight);
 
-	glEnable(GL_CULL_FACE);
+	// glEnable(GL_CULL_FACE);
 	glFrontFace(GL_CCW);
 
 	glEnable(GL_DEPTH_TEST);
 
+	glEnable(GL_BLEND);
+	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+	DEBUG("Creating origin vertex buffer");
+	GLfloat originVertices[] = {
+	//  X     Y     Z     R     G     B
+		0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
+		1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f,
+		0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f,
+		0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,
+		0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f,
+		0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f
+	};
+	GLuint originVBO;
+	glGenBuffers(1, &originVBO);
+	glBindBuffer(GL_ARRAY_BUFFER, originVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(originVertices), originVertices, GL_STATIC_DRAW);
+
+	glGenVertexArrays(1, &originVAO);
+	glBindVertexArray(originVAO);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), 0);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 6 * sizeof(GLfloat), (void*)(3 * sizeof(GLfloat)));
+	glEnableVertexAttribArray(1);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+
 	initialiseStatusDisplay();
 
 	recalculateProjectionMatrix();
@@ -206,15 +316,8 @@ void init(void) {
 	INFO("--- Initialisation done ---");
 }
 
-GLfloat currentHue = 0.0f;
+void drawCube(mat4 modelMatrix, mat4 viewMatrix) {
-
-void drawCube(vec3 position, mat4 initialModelMatrix, mat4 viewMatrix) {
-	mat4 modelMatrix;
 	mat4 modelViewMatrix;
-
-	mat4Translate(modelMatrix, initialModelMatrix, position);
-
-	// combine model and view matrix to model-view matrix
 	mat4Multiply(modelViewMatrix, viewMatrix, modelMatrix);
 
 	// send modelView and projection matrix to shader
@@ -227,54 +330,198 @@ void drawCube(vec3 position, mat4 initialModelMatrix, mat4 viewMatrix) {
 	glDrawElements(GL_TRIANGLES, 48, GL_UNSIGNED_INT, 0);
 }
 
+GLfloat clamp(GLfloat d, GLfloat min, GLfloat max) {
+	const GLfloat t = d < min ? min : d;
+	return t > max ? max : t;
+}
+
+GLfloat mapTo01(GLfloat d, GLfloat min, GLfloat max) {
+	return (clamp(d, min, max) - min) * (1 / (max - min));
+}
+
 void draw(void) {
+	// 0.0: virtual view
+	// 0.1 transition to real view
+	// 0.15 done
+	// 0.3 start view transformation
+	// 0.35 done
+	// 0.4 start projection
+	// 0.45 done
 	updateStatusDisplay();
 
+	mat4 identity;
+	mat4Identity(identity);
+
+	mat4 projectionMatrix;
+	// mat4Interpolate(projectionMatrix, identity, projectionMatrix, mapTo01(currentHue, 0.0f, 0.1f));
+
 	// counter for animation
-	currentHue += 0.0005f;
+	currentHue += 0.0001f;
+	int state = glfwGetKey(window, GLFW_KEY_SPACE);
+	if (state == GLFW_PRESS)
+	{
+		currentHue += 0.001f;
+	}
 	if (currentHue > 1.0) currentHue = 0.0f;
 
 	// clear colour and depth buffer
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-	// select program
-	glUseProgram(program);
 
 	// build view matrix
 	mat4 viewMatrix;
 
 	// mat4Identity(viewMatrix);
-	vec3 cameraPos = {0.0f, 1.0f, 1.3f};
+	vec3 cameraPos = {cos(currentHue * 6 * M_PI) * 3.0f, 3.0f + sin(currentHue * 12 * M_PI) * 0.5, sin(currentHue * 6 * M_PI) * 3.0f};
-	vec3 cameraLookAt = {0.0f, 0.2f, 0.0f};
+	vec3 cameraLookAt = {0.0f, 0.0f, 0.0f};
 	vec3 cameraUp = {0.0f, 1.0f, 0.0f};
 	mat4BuildLookAt(viewMatrix, cameraPos, cameraLookAt, cameraUp);
 
+
+	vec3 virtualCameraPosition = {1.5f, 1.0f, 1.0f};
+	vec3 virtualCameraLookAt = {0.0f, 0.0f, -1.0f};
+
+	// calculate virtual lookAt and projection
+	mat4 virtualCameraMatrix;
+	mat4 virtualProjectionMatrix;
+	mat4BuildLookAt(virtualCameraMatrix, virtualCameraPosition, virtualCameraLookAt, cameraUp);
+	mat4BuildPerspective(virtualProjectionMatrix, 60 * M_PI / 180, aspect, 1, 4);
+
+	mat4 viewFrustumModelView;
+	mat4Inverse(viewFrustumModelView, virtualProjectionMatrix);
+
+	mat3 mat3CameraRotationMatrix;
+	mat3From4(mat3CameraRotationMatrix, virtualCameraMatrix);
+	mat3Inverse(mat3CameraRotationMatrix, mat3CameraRotationMatrix);
+	mat4 cameraRotationMatrix;
+	mat4From3(cameraRotationMatrix, mat3CameraRotationMatrix);
+
+	mat4Interpolate(projectionMatrix, virtualProjectionMatrix, realProjectionMatrix, mapTo01(currentHue, 0.1f, 0.15f));
+	mat4Interpolate(viewMatrix, virtualCameraMatrix, viewMatrix, mapTo01(currentHue, 0.1f, 0.15f));
+
+	mat4Interpolate(projectionMatrix, projectionMatrix, virtualProjectionMatrix, mapTo01(currentHue, 0.7f, 0.75f));
+	mat4Interpolate(viewMatrix, viewMatrix, virtualCameraMatrix, mapTo01(currentHue, 0.7f, 0.75f));
+
+	mat4Interpolate(virtualCameraMatrix, identity, virtualCameraMatrix, mapTo01(currentHue, 0.3f, 0.35f));
+	mat4Interpolate(virtualProjectionMatrix, identity, virtualProjectionMatrix, mapTo01(currentHue, 0.4f, 0.45f) * mapTo01(currentHue, 0.4f, 0.45f));
+
+	mat4Interpolate(virtualCameraMatrix, virtualCameraMatrix, identity, mapTo01(currentHue, 0.7f, 0.75f));
+	mat4Interpolate(virtualProjectionMatrix, virtualProjectionMatrix, identity, mapTo01(currentHue, 0.7f, 0.75f));
+
+
+
+	glUseProgram(program);
+
+	GLuint brightnessLocation = glGetUniformLocation(program, "uBrightness");
+
 	GLuint projectionLocation = glGetUniformLocation(program, "uProjection");
 	glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, projectionMatrix);
 
-
+	// cubes.
-	// build model Matrix
 	mat4 modelMatrix;
 	vec3 scale;
 	vec3 position;
 
-	float scales[] = {0.5f, 0.4f, 0.3f, 0.2f, 0.1f, 0.09f, 0.08f, 0.07f, 0.06f, 0.05f};
+	// cube 1
-	for (int i = 0; i < 10; i++) {
+	mat4Identity(modelMatrix);
-		mat4Identity(modelMatrix);
 
-		vec3Set(scale, scales[i], 0.05f, scales[i]);
+	vec3Set(scale, 0.5f, 0.5f, 0.5f);
-		mat4Scale(modelMatrix, modelMatrix, scale);
+	mat4Scale(modelMatrix, modelMatrix, scale);
 
-		mat4RotateY(modelMatrix, modelMatrix, currentHue * 2 * M_PI + (i / 5.0f * M_PI));
+	mat4RotateY(modelMatrix, modelMatrix, 0.5f);
 
-		vec3Set(position, 0.0f, i * 0.05f, 0.0f);
+	vec3Set(position, -0.3f, 0.5f, -0.4f);
-		mat4Translate(modelMatrix, modelMatrix, position);
+	mat4Translate(modelMatrix, modelMatrix, position);
 
-		drawCube(position, modelMatrix, viewMatrix);
+	mat4Multiply(modelMatrix, virtualCameraMatrix, modelMatrix);
+	mat4Multiply(modelMatrix, virtualProjectionMatrix, modelMatrix);
+
+	glUniform1f(brightnessLocation, 1.0f);
+	drawCube(modelMatrix, viewMatrix);
+
+	// cube 2
+	mat4Identity(modelMatrix);
+
+	vec3Set(scale, 0.3f, 0.3f, 0.3f);
+	mat4Scale(modelMatrix, modelMatrix, scale);
+
+	mat4RotateY(modelMatrix, modelMatrix, 0.5f);
+
+	vec3Set(position, -0.9f, 0.3f, -3.8f);
+	mat4Translate(modelMatrix, modelMatrix, position);
+
+	mat4Multiply(modelMatrix, virtualCameraMatrix, modelMatrix);
+	mat4Multiply(modelMatrix, virtualProjectionMatrix, modelMatrix);
+
+	glUniform1f(brightnessLocation, 1.0f);
+	drawCube(modelMatrix, viewMatrix);
+
+
+	// draw virtual camera
+	mat4Identity(modelMatrix);
+
+	vec3Set(scale, 0.2f, 0.15f, 0.05f);
+	mat4Scale(modelMatrix, modelMatrix, scale);
+
+	// apply rotations to camera
+
+	mat4Multiply(modelMatrix, cameraRotationMatrix, modelMatrix);
+
+	mat4Translate(modelMatrix, modelMatrix, virtualCameraPosition);
+	mat4Multiply(modelMatrix, virtualCameraMatrix, modelMatrix);
+
+	glUniform1f(brightnessLocation, 0.0f);
+	
+	if (currentHue < 0.37f) {
+		drawCube(modelMatrix, viewMatrix);
 	}
 
 
 
+	glUseProgram(originProgram);
+
+	projectionLocation = glGetUniformLocation(originProgram, "uProjection");
+	glUniformMatrix4fv(projectionLocation, 1, GL_FALSE, projectionMatrix);
+
+	GLuint modelViewLocation = glGetUniformLocation(originProgram, "uModelView");
+	glUniformMatrix4fv(modelViewLocation, 1, GL_FALSE, viewMatrix);
+
+	glBindVertexArray(originVAO);
+	glLineWidth(5.0f);
+	glDrawArrays(GL_LINES, 0, 6);
+
+	if (currentHue > 0.35f && currentHue < 0.65) {
+		mat4Multiply(viewFrustumModelView, virtualProjectionMatrix, viewFrustumModelView);
+		mat4Multiply(viewFrustumModelView, viewMatrix, viewFrustumModelView);
+
+		glUniformMatrix4fv(modelViewLocation, 1, GL_FALSE, viewFrustumModelView);
+
+		glBindVertexArray(vertexArrayObject);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, lineIndexBuffer);
+		glDrawElements(GL_LINES, 24, GL_UNSIGNED_INT, 0);
+	}
+
+	// draw floor
+	glUseProgram(floorProgram);
+	glBindVertexArray(vertexArrayObject);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, floorIndexBuffer);
+
+	glUniformMatrix4fv(glGetUniformLocation(floorProgram, "uView"), 1, GL_FALSE, viewMatrix);
+	glUniformMatrix4fv(glGetUniformLocation(floorProgram, "uProjection"), 1, GL_FALSE, projectionMatrix);
+
+	mat4 floorModelMatrix;
+	vec3 floorScale;
+	mat4Identity(floorModelMatrix);
+	vec3Set(floorScale, 10.0f, 0.01f, 10.0f);
+	mat4Scale(floorModelMatrix, floorModelMatrix, floorScale);
+
+	glUniformMatrix4fv(glGetUniformLocation(floorProgram, "uModel"), 1, GL_FALSE, floorModelMatrix);
+
+	glDepthMask(GL_FALSE);
+	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+	glDepthMask(GL_TRUE);
+
+
 }
 
 void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
@@ -303,9 +550,7 @@ int main(int argc, char const *argv[])
 	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
 	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
 
-	glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER , GLFW_TRUE);
+	window = glfwCreateWindow(initialWindowWidth, initialWindowHeight, "CG1", NULL, NULL);
-
-	GLFWwindow* window = glfwCreateWindow(initialWindowWidth, initialWindowHeight, "CG1", NULL, NULL);
 
 	aspect = (float)initialWindowWidth / initialWindowHeight;
 	if (!window) {

src/shaders/floor-fragment.glsl

@@ -0,0 +1,8 @@
+#version 330 core
+
+in vec4 vPosition;
+
+void main() {
+	gl_FragColor = mix(vec4(1,1,1,0.5), vec4(0.8,0.8,0.8,0.5), step(0, sin(vPosition.x * 3.14159) * sin(vPosition.z * 3.14159)));
+	// gl_FragColor = vec4(1,0,0,1);
+}

src/shaders/floor-vertex.glsl

@@ -0,0 +1,14 @@
+#version 330 core
+
+layout (location = 0) in vec3 aPosition;
+
+uniform mat4 uModel;
+uniform mat4 uView;
+uniform mat4 uProjection;
+
+out vec4 vPosition;
+
+void main() {
+	vPosition = uModel * vec4(aPosition, 1);
+	gl_Position = uProjection * uView * vPosition;
+}

src/shaders/fragment.glsl

@@ -8,8 +8,10 @@ vec3 colors[6] = vec3[6](
 	vec3(0.5, 1.0, 1.0) 
 );
 
+uniform float uBrightness;
+
 void main() {
 	// hacky solution to give each side a different colour
 	int side = gl_PrimitiveID / 2;
-	gl_FragColor = vec4(colors[side], 1.0);
+	gl_FragColor = vec4(colors[side] * uBrightness, 1.0);
 }

src/shaders/origin-fragment.glsl

@@ -0,0 +1,7 @@
+#version 330 core
+
+in vec3 vertexColor;
+
+void main() {
+	gl_FragColor = vec4(vertexColor, 1.0);
+}

src/shaders/origin-vertex.glsl

@@ -0,0 +1,13 @@
+#version 330 core
+layout (location = 0) in vec3 aPosition;
+layout (location = 1) in vec3 aColor;
+
+uniform mat4 uModelView;
+uniform mat4 uProjection;
+
+out vec3 vertexColor;
+
+void main() {
+	vertexColor = aColor;
+	gl_Position = uProjection * uModelView * vec4(aPosition, 1.0);
+}