Displaying a skybox

BaseGLProject/BaseGLProject.vcxproj

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
@@ -157,6 +157,7 @@
     <ClCompile Include="Models\Mesh.cpp" />
     <ClCompile Include="MyGLWindow.cpp" />
     <ClCompile Include="Shader.cpp" />
+    <ClCompile Include="Skybox.cpp" />
     <ClCompile Include="Source.cpp" />
     <ClCompile Include="Texture.cpp" />
     <ClCompile Include="Viewer.cpp" />
@@ -179,6 +180,7 @@
     <ClInclude Include="MyGLWindow.h" />
     <ClInclude Include="SceneContext.h" />
     <ClInclude Include="Shader.h" />
+    <ClInclude Include="Skybox.h" />
     <ClInclude Include="Texture.h" />
     <ClInclude Include="Viewer.h" />
   </ItemGroup>
@@ -189,6 +191,8 @@
     <None Include="base_light.vert" />
     <None Include="nmap.frag" />
     <None Include="nmap.vert" />
+    <None Include="skybox.frag" />
+    <None Include="skybox.vert" />
     <None Include="spotlight.frag" />
     <None Include="spotlight.vert" />
     <None Include="tex_base_light.frag" />

BaseGLProject/BaseGLProject.vcxproj.filters

@@ -66,6 +66,9 @@
     <ClCompile Include="Texture.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="Skybox.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="ModelView.h">
@@ -125,6 +128,9 @@
     <ClInclude Include="Texture.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="Skybox.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="simple.frag">
@@ -178,6 +184,12 @@
     <None Include="nmap.frag">
       <Filter>Shaders</Filter>
     </None>
+    <None Include="skybox.vert">
+      <Filter>Shaders</Filter>
+    </None>
+    <None Include="skybox.frag">
+      <Filter>Shaders</Filter>
+    </None>
   </ItemGroup>
   <ItemGroup>
     <Image Include="brick1.jpg">

BaseGLProject/MyGLWindow.cpp

@@ -129,6 +129,7 @@ void MyGlWindow::setup()
 	glEnable(GL_DEPTH_BUFFER);
 	glEnable(GL_TEXTURE_2D);
 
+	skybox.initialize("Models/Skybox/");
 	textureSetup();
 	shaderSetup();
 	lightSetup();
@@ -160,7 +161,7 @@ void MyGlWindow::setup()
 	
 	//meshes.emplace("Mountain", new Mesh("mountain/mount.blend1.obj", shaders["TexBaseLight"]));	
 
-	meshes.emplace("Sponza", new Mesh("sponza/sponza.obj", shaders["TexBaseLight"]));
+	//meshes.emplace("Sponza", new Mesh("sponza/sponza.obj", shaders["TexBaseLight"]));
 	//meshes["Sponza"]->addTranslation(glm::vec4(0, -200, 0, 1));	
 
 
@@ -206,6 +207,7 @@ void MyGlWindow::draw()
 	//_scnctx.adjustSpots();
 	for (auto it = meshes.begin(); it != meshes.end(); it++)
 		(*it).second->draw(_scnctx);
+	skybox.draw(_scnctx);
 }
 
 void MyGlWindow::resize(int w, int h)

BaseGLProject/MyGLWindow.h

@@ -4,6 +4,7 @@
 #include "GL/glew.h"
 #include <string>
 #include <vector>
+#include "Skybox.h"
 #include "Shader.h"
 #include "ModelView.h"
 #include "Viewer.h"
@@ -22,7 +23,7 @@ public:
 	MyGlWindow(int w, int h);	
 	~MyGlWindow();
 
-	void draw();
+	void draw();	
 	void setBgColor(float bgColor[3]);
 			
 	std::map<std::string, Shader *> shaders;
@@ -38,6 +39,7 @@ private:
 
 	float _bgColor[3];	
 
+	Skybox skybox;
 	GLuint _vaoHandle;
 	GLuint _iboHandle;	
 	

BaseGLProject/SceneContext.h

@@ -4,6 +4,7 @@
 #include <glm/mat4x4.hpp>
 #include <glm/vec3.hpp>
 #include "Texture.h"
+#include "Light.h"
 
 struct SceneContext
 {

BaseGLProject/Skybox.cpp

@@ -1,4 +1,5 @@
 #include "Skybox.h"
+#include "imgui/stb_image.h"
 
 Skybox::Skybox()
 {
@@ -57,40 +58,71 @@ Skybox::Skybox()
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, 36 * sizeof(GLuint), el, GL_STATIC_DRAW);
 
-	glVertexAttribPointer(4, 3, GL_FLOAT, GL_FALSE, 0, NULL);
+	//glVertexAttribPointer(4, 3, GL_FLOAT, GL_FALSE, 0, NULL);
-	glEnableVertexAttribArray(4);
+	//glEnableVertexAttribArray(4);
 
+	shader.initFromFiles("skybox.vert", "skybox.frag");
+}
+
+void Skybox::initialize(std::string skybox_dir)
+{
 	glActiveTexture(GL_TEXTURE0);
 	glGenTextures(1, &texID);  //set the texID as a member variable
 	glBindTexture(GL_TEXTURE_CUBE_MAP, texID);
 
-	const char * suffixes[] = { "left", "right", "top", "down", "back", "front" };
+
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+
+	const char * suffixes[] = { "left", "right", "top", "down", "back", "front"};
 
 	GLuint targets[] = {
 	GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
 	GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
 	GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
-	};
+	};	
 
-	for (int i = 0; i < 6; i++) {
+	for (int i = 0; i < 6; i++) {		
-		int channel;
+		int channel, width, height;
-		int width, height;
+		unsigned char *image;
 		std::string filename;
-		filename = std::string("Models/skybox/" + suffixes[i]) + string(".jpg");
+		filename = std::string(skybox_dir + suffixes[i]) + std::string(".JPG");
-		unsigned char * image = SOIL_load_image(filename.c_str(), &width, &height, &channel, SOIL_LOAD_RGB);
+		image = stbi_load(filename.c_str(), &width, &height, &channel, 0);
 		glTexImage2D(targets[i], 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
 		glGenerateMipmap(GL_TEXTURE_2D);
-		SOIL_free_image_data(image);
+		stbi_image_free(image);
 	}
 
-
+	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);	
 }
 
-
 Skybox::~Skybox()
 {
+	glDeleteBuffers(1, &vector_vbo);
+	glDeleteBuffers(1, &ibo);
+	glDeleteVertexArrays(1, &vao);	
 }
 
-void Skybox::draw()
+void Skybox::draw(SceneContext &ctx)
 {
+	shader.use();
+
+	glm::mat4x4 mvpMatrix = ctx.projectionMatrix * ctx.viewMatrix * glm::mat4(1.0);
+	glUniformMatrix4fv(shader.addUniform("mvp"), 1, GL_FALSE, glm::value_ptr(mvpMatrix));
+	glUniform1i(shader.addUniform("DrawSkyBox"), GL_TRUE);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_CUBE_MAP, texID);	
+	glUniform1i(shader.addUniform("CubeMapTex"), 0);
+	glBindVertexArray(vao);
+	
+	int size;
+	glGetBufferParameteriv(GL_ELEMENT_ARRAY_BUFFER, GL_BUFFER_SIZE, &size);
+	glDrawElements(GL_TRIANGLES, size / sizeof(GLuint), GL_UNSIGNED_INT, 0);
+
+	glBindVertexArray(0);
+	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+	shader.disable();
 }

BaseGLProject/Skybox.h

@@ -8,18 +8,22 @@
 #include <glm/mat4x4.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtc/matrix_inverse.hpp>
+#include <glm/gtc/type_ptr.hpp>
 #include "Loader.h"
+#include "SceneContext.h"
 
 class Skybox
 {
 private:
 	unsigned int vao;
 	unsigned int vector_vbo;
-	unsigned int ibo;
+	unsigned int ibo;	
 	GLuint texID;
+	ShaderProgram shader;
 public:
 	Skybox();
+	void initialize(std::string skybox_dir);
 	~Skybox();
-	void draw();
+	void draw(SceneContext &ctx);
 };
 

BaseGLProject/skybox.frag

@@ -0,0 +1,21 @@
+#version 440
+
+out vec4 FragColors;
+
+in vec3 reflectDir;
+
+uniform bool DrawSkyBox;
+uniform samplerCube CubeMapTex;
+
+float rand(vec2 co){
+    return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
+}
+
+void main()
+{ 	
+	vec4 texColor = texture(CubeMapTex, reflectDir);
+	if (DrawSkyBox == true)
+		FragColors = texColor;
+	else
+		FragColors = vec4(1, 1, rand(reflectDir.xy), 1);
+}

BaseGLProject/skybox.vert

@@ -0,0 +1,25 @@
+#version 440
+
+layout(location=0) in vec3 coord3d;
+layout(location=1) in vec3 v_normal;
+layout(location=2) in vec3 v_color;
+layout(location=3) in vec2 v_texmap;
+
+out vec3 reflectDir;
+
+uniform mat4 mvp;
+uniform bool DrawSkyBox;
+
+void main(void)
+{		
+
+
+//For drawing a mesh with reflected skybox
+//P = (vec3(ModelMAtrix * vec4(Vertexpos, 1)
+// N = normalize(ModelMatrix * VertexNormals);
+//V = normalize(WorldCamPos - worldPos);
+//ReflectDir = reflect(-worldview, worldNorm);	
+	if (DrawSkyBox == true)
+		reflectDir = coord3d;
+	gl_Position = mvp * vec4(coord3d, 1.0f);
+}