render to framebufer

5 files changed, 138 insertions, 17 deletions

diff --git a/shaders/fbo_frag.glsl b/shaders/fbo_frag.glsl
new file mode 100644
index 0000000..cf1fafa
--- /dev/null
+++ b/shaders/fbo_frag.glsl
@@ -0,0 +1,13 @@
+#version 330 core

+out vec4 FragColor;

+  

+in vec2 TexCoords;

+

+uniform sampler2D screenTexture;

+

+void main()

+{ 

+    FragColor = vec4(

+        texture(screenTexture, TexCoords).rgb,

+        1.0);

+}

diff --git a/shaders/fbo_vert.glsl b/shaders/fbo_vert.glsl
new file mode 100644
index 0000000..fb80df5
--- /dev/null
+++ b/shaders/fbo_vert.glsl
@@ -0,0 +1,11 @@
+#version 330 core

+layout (location = 0) in vec2 aPos;

+layout (location = 1) in vec2 aTexCoords;

+

+out vec2 TexCoords;

+

+void main()

+{

+    gl_Position = vec4(aPos.x, aPos.y, 0.0, 1.0); 

+    TexCoords = aTexCoords;

+}

diff --git a/shaders/frag.glsl b/shaders/frag.glsl
index a92699c..a70915a 100644
--- a/shaders/frag.glsl
+++ b/shaders/frag.glsl
@@ -8,6 +8,7 @@ out vec4 FragColor;
 uniform vec3 objectColor;

 uniform vec3 lightColor;

 uniform vec3 lightPos;

+uniform vec3 viewPos;

 

 void main()

 {

@@ -20,6 +21,12 @@ void main()
   float ambientStrength = 0.1;

   vec3 ambient = ambientStrength * lightColor;

 

-  vec3 result = (ambient + diffuse) * objectColor;

+  float specularStrength = 0.5;

+  vec3 viewDir = normalize(viewPos - FragPos);

+  vec3 reflectDir = reflect(-lightDir, norm);

+  float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);

+  vec3 specular = specularStrength * spec * lightColor;

+

+  vec3 result = (ambient + diffuse + specular) * objectColor;

   FragColor = vec4(result, 1.0f);

-}
\ No newline at end of file
+}

diff --git a/shaders/vert.glsl b/shaders/vert.glsl
index fc3721a..6f48573 100644
--- a/shaders/vert.glsl
+++ b/shaders/vert.glsl
@@ -15,4 +15,4 @@ void main()
   gl_Position = projection * view * model * vec4(pos, 1.0);

   FragPos = vec3(model * vec4(pos, 1));

   Normal = normal;

-}
\ No newline at end of file
+}

diff --git a/src/main.cpp b/src/main.cpp
index c05d25e..41d5e76 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -51,10 +51,10 @@ private:
     glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLuint) * indices.size(),

                 indices.data(), GL_STATIC_DRAW);

 

-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, (void*)(0));

     glEnableVertexAttribArray(0);

-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, (void*)(sizeof(float) * 3));

+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, (void*)(0));

     glEnableVertexAttribArray(1);

+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(float) * 6, (void*)(sizeof(float) * 3));

 

     glBindVertexArray(0);

   }

@@ -142,6 +142,16 @@ struct arccam {
       rot.y = glm::radians(minY) * angleFactor;

   }

 

+  glm::vec3 getPos() {

+    float angle = rot.y / angleFactor;

+  

+    float camY = sin(angle) * exp(radius);

+    float camZ = cos(angle) * exp(radius);

+

+    glm::vec3 result(0.0, camY, camZ);

+    return glm::rotate(result, -rot.x / angleFactor, glm::vec3(0, 1, 0));

+  }

+

   glm::mat4 getViewMatrix() {

     float angle = rot.y / angleFactor;

   

@@ -160,14 +170,10 @@ private:
 

 std::string readFile(std::string filename) {

   std::ifstream ifs(filename, std::ios::binary);

-  ifs.seekg(0, ifs.end);

-  long length = ifs.tellg();

-  ifs.seekg(0, ifs.beg);

-  char *buffer = (char*)malloc(length);

-  ifs.read(buffer, length);

-  ifs.close();

-  std::string result(buffer);

-  free(buffer);

+  std::string result, line;

+  while (std::getline(ifs, line))

+    result += line + "\n";

+

   return result;

 }

 

@@ -213,7 +219,7 @@ GLuint compileShaders(const char *vertFilename, const char *fragFilename) {
   glGetShaderiv(vertShader, GL_COMPILE_STATUS, &success);

   if (!success) {

     glGetShaderInfoLog(vertShader, 512, NULL, infoLog);

-    printf("Error compiling vertex shader: %s\n", infoLog);

+    printf("Error compiling vertex shader(%s): %s\n", vertFilename, infoLog);

   }

 

   GLuint fragShader = glCreateShader(GL_FRAGMENT_SHADER);

@@ -225,7 +231,7 @@ GLuint compileShaders(const char *vertFilename, const char *fragFilename) {
   glGetShaderiv(fragShader, GL_COMPILE_STATUS, &success);

   if (!success) {

     glGetShaderInfoLog(fragShader, 512, NULL, infoLog);

-    printf("Error compiling fragment shader: %s\n", infoLog);

+    printf("Error compiling fragment shader(%s): %s\n", fragFilename, infoLog);

   }

 

   // Link Shader Program

@@ -251,6 +257,8 @@ GLuint compileShaders(const char *vertFilename, const char *fragFilename) {
 int main() {

   // Window Setup

 

+  const int width = 1600, height = 900;

+

   sf::ContextSettings settings;

   settings.depthBits = 24;

   settings.antialiasingLevel = 0;

@@ -285,6 +293,69 @@ int main() {
 

   glm::mat4 proj = glm::perspective(glm::radians(45.0f), (float)window.getSize().x / window.getSize().y, 0.001f, 1000.0f);

 

+  // Framebuffer

+  GLuint fbo;

+  glGenFramebuffers(1, &fbo);

+  glBindFramebuffer(GL_FRAMEBUFFER, fbo);

+  

+  GLuint renderTexture;

+  glGenTextures(1, &renderTexture);

+  glBindTexture(GL_TEXTURE_2D, renderTexture);

+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);

+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

+  //glBindTexture(GL_TEXTURE_2D, 0);

+  glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, renderTexture, 0);

+

+  GLuint rbo;

+  glGenRenderbuffers(1, &rbo);

+  glBindRenderbuffer(GL_RENDERBUFFER, rbo);

+  glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);

+  //glBindRenderbuffer(GL_RENDERBUFFER, 0);

+  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);

+

+  if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE) {

+    printf("Successfully created framebuffer\n");

+  }

+  glBindFramebuffer(GL_FRAMEBUFFER, 0);

+  

+  GLuint screenShaderProgram = compileShaders("shaders/fbo_vert.glsl", "shaders/fbo_frag.glsl");

+  glUseProgram(screenShaderProgram);

+  glUniform1i(glGetUniformLocation(screenShaderProgram, "screenTexture"), 0);

+

+  // Screen VAO

+  

+  GLuint screenVBO;

+  glGenBuffers(1, &screenVBO);

+

+  GLuint screenVAO;

+  glGenVertexArrays(1, &screenVAO);

+

+  glBindVertexArray(screenVAO);

+

+  float screenVerts[] = {

+    -1.0f, +1.0f, +0.0f, +1.0f,

+    -1.0f, -1.0f, +0.0f, +0.0f,

+    +1.0f, -1.0f, +1.0f, +0.0f,

+ 

+    -1.0f, +1.0f, +0.0f, +1.0f,

+    +1.0f, -1.0f, +1.0f, +0.0f,

+    +1.0f, +1.0f, +1.0f, +1.0f,

+  };

+

+  glBindBuffer(GL_ARRAY_BUFFER, screenVBO);

+  glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4,

+              screenVerts, GL_STATIC_DRAW);

+

+  glEnableVertexAttribArray(0);

+  glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, (void*)(0));

+  glEnableVertexAttribArray(1);

+  glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(float) * 4, (void*)(sizeof(float) * 2));

+

+  glBindVertexArray(0);

+

+  // Config

+

   struct {

     bool wireframe = false;

     bool freecam = false;

@@ -343,10 +414,11 @@ int main() {
 

     prevMouse = sf::Mouse::isButtonPressed(sf::Mouse::Right);

 

-    // Render

+    // Render to fbo

 

+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);

+    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);

     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

-

     glEnable(GL_DEPTH_TEST);

 

     if (options.wireframe)

@@ -380,11 +452,27 @@ int main() {
     glUniform3fv(

       glGetUniformLocation(shaderProgram, "lightPos"),

       1, glm::value_ptr(lightPos));

+    glUniform3fv(

+      glGetUniformLocation(shaderProgram, "viewPos"),

+      1, glm::value_ptr(options.freecam ? freeCam.pos : arcCam.getPos()));

 

     m.draw();

+

+    // Render fbo to screen

     

     glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);

 

+    glBindFramebuffer(GL_FRAMEBUFFER, 0);

+    glDisable(GL_DEPTH_TEST);

+    glClearColor(1.0f, 1.0f, 1.0f, 1.0f);

+    glClear(GL_COLOR_BUFFER_BIT);

+    glUseProgram(screenShaderProgram);

+

+    glBindVertexArray(screenVAO);

+    glBindTexture(GL_TEXTURE_2D, renderTexture);

+    glDrawArrays(GL_TRIANGLES, 0, 6);

+    glBindVertexArray(0);

+

     ImGui::SFML::Update(window, deltaClock.restart());

 

     ImGui::Begin("Options");

@@ -412,5 +500,7 @@ int main() {
     window.display();

   }

 

+  glDeleteFramebuffers(1, &fbo);

+

   return 0;

 }
\ No newline at end of file