linear fog

main.cpp

@@ -44,8 +44,8 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	RECT rect;
 	rect.left = 0;
 	rect.top = 0;
-	rect.right = 800;
-	rect.bottom = 600;
+	rect.right = 1280;
+	rect.bottom = 720;
 	AdjustWindowRect(&rect, WS_OVERLAPPEDWINDOW, FALSE);
 
 	HWND hwnd = CreateWindowEx(NULL, "OpenGL", "RenderWindow", WS_OVERLAPPEDWINDOW, 100, 100, rect.right - rect.left, rect.bottom - rect.top, NULL, NULL, hInstance, NULL);
@@ -95,13 +95,16 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	gpuProgram.DetectUniform("U_Cutoff");
 	gpuProgram.DetectUniform("U_SpecularLightColor");
 	gpuProgram.DetectUniform("U_SpecularMaterial");
-	gpuProgram.DetectUniform("U_EyePos");
+	
+	gpuProgram.DetectUniform("U_FogStart");
+	gpuProgram.DetectUniform("U_FogEnd");
+	gpuProgram.DetectUniform("U_FogColor");
 
 	
 
 	//init 3d model
 	ObjModel cube;
-	cube.Init("res/model/Cube.obj");
+	cube.Init("res/model/Sphere.obj");
 
 	float identity[] = {
 		1.0f,0,0,0,
@@ -112,10 +115,10 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 
 	float ambientLightColor[] = { 0.4f,0.4f,0.4f,1.0f };
 	float ambientMaterial[] = { 0.2f,0.2f,0.2f,1.0f };
-	float diffuseLightColor[] = { 1.0f,1.0f,1.0f,1.0f };
+	float diffuseLightColor[] = { 0.1f,0.4f,0.7f,1.0f };
 	float diffuseMaterial[] = { 0.6f, 0.6f, 0.6f, 1.0f };
-	float lightPos[] = { 0.0f,1.0f,0.0f,0.0f };
-	float diffuseIntensity = 2.5f;
+	float lightPos[] = { 1.0f,1.0f,0.0f,0.0f };
+	float diffuseIntensity = 1.0f;
 
 	float spotLightDirection[] = { 0.0f, -1.0f, 0.0f, 628.0f };
 	float spotLightCutoff = 5.0f;
@@ -123,16 +126,28 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 	float specularMaterial[] = { 1.0f,1.0f,1.0f,1.0f };
 	float eyePos[] = { 0.0f,0.0f,0.0f };
 
-	glm::mat4 cubeModelMatrix = glm::translate<float>(-2.0f, 0.0f, -6.0f) * glm::rotate(-30.0f, 1.0f, 1.0f, 1.0f);
+	float fogStart = 2.0f;
+	float fogEnd = 23.0f;
+	float fogColor[] = { 0.6f, 0.6f, 0.6f, 1.0f };
+
+	glm::mat4 cubeModelMatrix = glm::translate<float>(-2.2f, 0.0f, -4.0f) * glm::rotate(-30.0f, 1.0f, 1.0f, 1.0f);
 	glm::mat4 cubeNormalMatrix = glm::inverseTranspose(cubeModelMatrix);
-	glm::mat4 viewMatrix = glm::lookAt(glm::vec3(1.0f, 0.5f, -10.0f), glm::vec3(0.0f, 0.0f, -1.0f), glm::vec3(0.0f, 1.0f, 0.0f));
-	glm::mat4 projectionMatrix = glm::perspective(50.0f, 800.0f / 600.0f, 0.1f, 1000.0f);
+
+	glm::mat4 cubeModelMatrix2 = glm::translate<float>(-2.0f, 0.0f, -12.0f) * glm::rotate(-30.0f, 1.0f, 1.0f, 1.0f);
+	glm::mat4 cubeNormalMatrix2 = glm::inverseTranspose(cubeModelMatrix);
+
+	glm::mat4 cubeModelMatrix3 = glm::translate<float>(-0.4f, 0.0f, -20.0f) * glm::rotate(-30.0f, 1.0f, 1.0f, 1.0f);
+	glm::mat4 cubeNormalMatrix3 = glm::inverseTranspose(cubeModelMatrix);
+
+
+	//glm::mat4 viewMatrix = glm::lookAt(glm::vec3(1.0f, 0.5f, -10.0f), glm::vec3(0.0f, 0.0f, -1.0f), glm::vec3(0.0f, 1.0f, 0.0f));
+	glm::mat4 projectionMatrix = glm::perspective(50.0f, (float)viewportWidth / (float)viewportHeight, 0.1f, 1000.0f);
 	
 
 	ShowWindow(hwnd, SW_SHOW);
 	UpdateWindow(hwnd);
 
-	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+	glClearColor(0.6f, 0.6f, 0.6f, 1.0f);
 	MSG msg;
 	while (true)
 	{
@@ -149,10 +164,9 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 		glUseProgram(gpuProgram.mProgram);
 
-		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix));
+		
 		glUniformMatrix4fv(gpuProgram.GetLocation("V"), 1, GL_FALSE, identity);
 		glUniformMatrix4fv(gpuProgram.GetLocation("P"), 1, GL_FALSE, glm::value_ptr(projectionMatrix));
-		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix));
 
 		glUniform4fv(gpuProgram.GetLocation("U_AmbientLightColor"), 1, ambientLightColor);
 		glUniform4fv(gpuProgram.GetLocation("U_AmbientMaterial"), 1, ambientMaterial);
@@ -165,10 +179,25 @@ INT WINAPI WinMain(_In_ HINSTANCE hInstance, _In_opt_ HINSTANCE hPrevInstance, _
 		glUniform4fv(gpuProgram.GetLocation("U_SpecularLightColor"), 1, specularLightColor);
 		glUniform4fv(gpuProgram.GetLocation("U_SpecularMaterial"), 1, specularMaterial);
 		glUniform3fv(gpuProgram.GetLocation("U_EyePos"), 1, eyePos);
+		glUniform1f(gpuProgram.GetLocation("U_FogStart"), fogStart);
+		glUniform1f(gpuProgram.GetLocation("U_FogEnd"), fogEnd);
+		glUniform4fv(gpuProgram.GetLocation("U_FogColor"), 1, fogColor);
 
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix));
+		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
+		cube.Draw();
+
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix2));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix2));
 		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
 		cube.Draw();
 
+
+		glUniformMatrix4fv(gpuProgram.GetLocation("M"), 1, GL_FALSE, glm::value_ptr(cubeModelMatrix3));
+		glUniformMatrix4fv(gpuProgram.GetLocation("NM"), 1, GL_FALSE, glm::value_ptr(cubeNormalMatrix3));
+		cube.Bind(gpuProgram.GetLocation("pos"), gpuProgram.GetLocation("texcoord"), gpuProgram.GetLocation("normal"));
+		cube.Draw();
 		glUseProgram(0);
 		glFlush();
 		SwapBuffers(dc);

res/shader/forg.fs

@@ -10,9 +10,20 @@ uniform vec3 U_EyePos;
 uniform vec4 U_SpecularLightColor;
 uniform vec4 U_SpecularMaterial;
 
+uniform float U_FogStart;
+uniform float U_FogEnd;
+uniform vec4 U_FogColor;
 
 varying vec3 V_Normal;
 varying vec3 V_WorldPos;
+varying vec4 V_EyeSpacePos;
+
+
+float calculateLinearFog(float distance){
+	float fogAlpha = (distance - U_FogStart) / (U_FogEnd - U_FogStart);
+	fogAlpha = 1.0 - clamp(fogAlpha, 0.0, 1.0);
+	return fogAlpha;
+}
 
 void main()
 {
@@ -66,5 +77,6 @@ void main()
 	vec3 VD = normalize(U_EyePos - V_WorldPos);
 	vec4 specularColor =  U_SpecularLightColor * U_SpecularMaterial * pow(max(0.0, dot(RD,VD)) ,128);
 
-	gl_FragColor = ambientColor + diffuseColor;
+	float fogAlpha = calculateLinearFog(abs(V_EyeSpacePos.z/V_EyeSpacePos.w));
+	gl_FragColor = mix(U_FogColor,ambientColor + diffuseColor + specularColor, fogAlpha);
 }

res/shader/forg.vs

@@ -9,11 +9,13 @@ uniform mat4 NM;//Normal Matrix ʹ
 
 varying vec3 V_Normal;
 varying vec3 V_WorldPos;
+varying vec4 V_EyeSpacePos;
 void main()
 {
 	V_Normal = mat3(NM)*normal;
 	vec4 worldPos = M * vec4(pos, 1.0);
 	V_WorldPos = worldPos.xyz;
+	V_EyeSpacePos = V*worldPos;
 
 	gl_Position=P*V*M*vec4(pos,1.0);
 }