gamma correction, scaling renderbuffer

CMakeLists.txt

@@ -17,8 +17,8 @@ set(CMAKE_CXX_COMPILER "zig" c++ ${compile-target})
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(OpenGL_GL_PREFERENCE "GLVND")
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=undefined -g ")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=undefined -g")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g ")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g")
 
 
 project(
@@ -94,9 +94,12 @@ CPMAddPackage("gh:g-truc/glm#0.9.9.8")
 FetchContent_Declare(SDL2
   GIT_REPOSITORY https://github.com/libsdl-org/SDL
   GIT_TAG release-2.26.4
+  OVERRIDE_FIND_PACKAGE
 )
 FetchContent_MakeAvailable(SDL2)
 
+find_package(SDL2 REQUIRED)
+
 FetchContent_Declare(
         glad
         GIT_REPOSITORY https://github.com/Dav1dde/glad
@@ -111,6 +114,7 @@ if(NOT glad_POPULATED)
     add_subdirectory(${glad_SOURCE_DIR} ${glad_BINARY_DIR})
 endif()
 
+
 # https://github.com/cpm-cmake/CPM.cmake/issues/368
 add_library(imgui STATIC
     ${imgui_SOURCE_DIR}/imgui.cpp
@@ -124,8 +128,7 @@ add_library(imgui STATIC
 )
 target_include_directories(imgui PUBLIC ${imgui_SOURCE_DIR})
 target_compile_definitions(imgui PUBLIC -DIMGUI_DISABLE_OBSOLETE_FUNCTIONS) # optional imgui setting
-set_target_properties(imgui PROPERTIES FOLDER third-party) # optoinal IDE dir
-target_link_libraries(imgui PRIVATE SDL2-static)
+target_link_libraries(imgui PRIVATE SDL2)
 
 
 # ---- Declare executable ----
@@ -161,7 +164,7 @@ target_link_libraries(enttge_exe PRIVATE enttge_lib
     glm::glm
     glad
     refl-cpp
-    SDL2-static
+    SDL2
     spdlog
     imgui
     assimp)

README.md

@@ -24,10 +24,15 @@ cmake . -B build -Dcompile-target=aarch64-linux-gnu
 
 --- 
 
-- https://sketchfab.com/3d-models/maple-tree-4b27adcf92f644bdabf8ecc6c5bef399#download
-- https://sketchfab.com/3d-models/trees-low-poly-1d2dcca2ccb1496c85b7cc5789a2a261
-- https://sketchfab.com/3d-models/grass-patches-7b65ce8bc0514c75b4243c5251cd5984
-- https://sketchfab.com/3d-models/grass-c44c1f99f1f0403fb2a52a441d8af7be#download
-- https://sketchfab.com/3d-models/birch-tree-low-poly-3ef00a7105c54d37b3a0e528e1466b0b#download
-- https://sketchfab.com/3d-models/fern-515ff7eff08144e3be70a89eedbcbcc7#download
-- https://sketchfab.com/3d-models/purple-lilies-a73ee85609bf48ef98eb08b29590e40f#download
+```
+- "Xenia The Linux Mascot" (https://skfb.ly/oGJ8U) by nickisdoge is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Dry grass" (https://skfb.ly/oCWJT) by Pixel-bit is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Grass" (https://skfb.ly/oGoz6) by Luis Gustavo is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Dead Trees Demo" (https://skfb.ly/ouL8q) by Quadra3D is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+-  "Purple lilies" (https://skfb.ly/oFxXE) by MyVisoin is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Low Poly: Dead Tree" (https://skfb.ly/orGPV) by ClintonAbbott.Art is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Grass" (https://skfb.ly/oFZNX) by Luis Gustavo is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Trees Low Poly" (https://skfb.ly/6YpAS) by Igor_K. is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Dead Tree - PS1 Low Poly" (https://skfb.ly/oFnOT) by Wersaus33 is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+- "Pine Tree - PS1 Low Poly" (https://skfb.ly/oFnRn) by Wersaus33 is licensed under Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/).
+```

assets/shaders/screen.frag

@@ -5,8 +5,9 @@ in vec2 TexCoords;
 
 uniform sampler2D screenTexture;
 
-const float gamma = 2.2;
-uniform float exposure = 0.8;
+uniform float gamma = 2.2;
+uniform float exposure = 1.0;
+uniform bool use_hdr = false;
 
 layout (std140) uniform material_properties
 {
@@ -26,11 +27,15 @@ layout (std140) uniform material_properties
 void main()
 { 
     vec3 hdrcol = texture(screenTexture, TexCoords).rgb;
-    //vec3 mapped = vec3(1.0) - exp((-hdrcol) * exposure);
-    vec3 mapped = hdrcol / (hdrcol + vec3(1.0));
-    // gamma correction
-    mapped = pow(mapped, vec3(1.0 / gamma));
-
-    FragColor = vec4(mapped, 1.0);
+    if (use_hdr) {
+        vec3 mapped = vec3(1.0) - exp((-hdrcol) * exposure);
+        //vec3 mapped = hdrcol / (hdrcol + vec3(1.0));
+        // gamma correction
+        mapped = pow(mapped, vec3(1.0 / gamma));
+        FragColor = vec4(mapped, 1.0);
+        }
+    else {
+    FragColor = vec4(hdrcol, 1.0);
+    }
 
 }

source/main.cpp

@@ -151,10 +151,10 @@ struct g_buffer {
   /*
    * The output textures of the G fragment shader.
    */
-  GLuint attachments[3] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
+  GLuint attachments[3] = {GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2, GL_COLOR_ATTACHMENT3 };
 
   g_buffer(int width, int height) : g_buffer(width, height, 1) { }
-  g_buffer(int width, int height, int scaling) : screen_width(width), screen_height(height), logical_width(width), logical_height(height)  { }
+  g_buffer(int width, int height, float scaling) : screen_width(width), screen_height(height), logical_width(width*scaling), logical_height(height*scaling)  { }
 
   void create_buffers() {
 
@@ -193,7 +193,7 @@ struct g_buffer {
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, screen_x, screen_y, 0, GL_RGBA, GL_FLOAT, NULL);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, g_position, 0);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, attachments[0], GL_TEXTURE_2D, g_position, 0);
       
     // - normal color buffer
     glGenTextures(1, &g_normal);
@@ -201,7 +201,7 @@ struct g_buffer {
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, screen_x, screen_y, 0, GL_RGBA, GL_FLOAT, NULL);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D, g_normal, 0);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, attachments[1], GL_TEXTURE_2D, g_normal, 0);
       
     // - color + specular color buffer
     glGenTextures(1, &g_albedo_specular);
@@ -209,10 +209,10 @@ struct g_buffer {
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, screen_x, screen_y, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D, g_albedo_specular, 0);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, attachments[2], GL_TEXTURE_2D, g_albedo_specular, 0);
     
     // - tell OpenGL which color attachments we'll use (of this framebuffer) for rendering 
-    unsigned int attachments[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
+    //unsigned int attachments[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
     glDrawBuffers(3, attachments);
     glCheckError();
 
@@ -224,20 +224,20 @@ struct g_buffer {
   }
 
   void bind_textures() {
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(GL_TEXTURE_2D, g_position);
     glActiveTexture(GL_TEXTURE1);
-    glBindTexture(GL_TEXTURE_2D, g_normal);
+    glBindTexture(GL_TEXTURE_2D, g_position);
     glActiveTexture(GL_TEXTURE2);
+    glBindTexture(GL_TEXTURE_2D, g_normal);
+    glActiveTexture(GL_TEXTURE3);
     glBindTexture(GL_TEXTURE_2D, g_albedo_specular);
     }
 
 
   void present(std::shared_ptr<shader_handle> deferred_lighting, GLuint quad_vao) {
     bind_textures();
-    deferred_lighting->set("gPosition", 0);
-    deferred_lighting->set("gNormal", 1);
-    deferred_lighting->set("gAlbedoSpec", 2);
+    deferred_lighting->set("gPosition", 1);
+    deferred_lighting->set("gNormal", 2);
+    deferred_lighting->set("gAlbedoSpec", 3);
     deferred_lighting->use();
     glDisable(GL_DEPTH_TEST);
 
@@ -245,6 +245,7 @@ struct g_buffer {
     //glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
     //glBlitFramebuffer(0, 0, logical_width, logical_height, 0, 0, screen_width, screen_height, GL_COLOR_BUFFER_BIT, GL_NEAREST); 
 
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
     glBindVertexArray(quad_vao);
     glDrawArrays(GL_TRIANGLES, 0, 6);
     glCheckError();
@@ -253,116 +254,6 @@ struct g_buffer {
 };
 
 
-struct g_buffer_multisampled {
-  GLuint fbo;
-  int width, height;
-  // texture ids
-  GLuint g_position, g_normal, g_albedo_specular;
-  GLuint stencil_depth;
-  g_buffer g_buffer_out;
-  /*
-   * The output textures of the G fragment shader.
-   */
-  GLuint attachments[3] = {GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
-
-  g_buffer_multisampled(int width, int height) : width(width), height(height), g_buffer_out(width, height) { }
-
-  void create_out_buffers() {
-    g_buffer_out.create_buffers();
-  }
-
-  void create_buffers() {
-    GLuint samples = 2;
-
-    glGenFramebuffers(1, &fbo);
-    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-
-    int screen_x = width;
-    int screen_y = height;
-
-    // bind to the existing framebuffer
-    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
-
-    // depth test and stencil texture
-    glGenTextures(1, &stencil_depth);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, stencil_depth);
-    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE,
-                 samples,
-                 GL_DEPTH24_STENCIL8,
-                 width,
-                 height,
-                 0);
-    glCheckError();
-
-    glFramebufferTexture2D(GL_FRAMEBUFFER,
-                           GL_DEPTH_STENCIL_ATTACHMENT,
-                           GL_TEXTURE_2D_MULTISAMPLE,
-                           stencil_depth,
-                           0);
-
-    glCheckError();
-
-    // - position color buffer
-    glGenTextures(1, &g_position);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_position);
-    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA16F, screen_x, screen_y, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, g_position, 0);
-    glCheckError();
-      
-    // - normal color buffer
-    glGenTextures(1, &g_normal);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_normal);
-    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA16F, screen_x, screen_y, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D_MULTISAMPLE, g_normal, 0);
-    glCheckError();
-      
-    // - color + specular color buffer
-    glGenTextures(1, &g_albedo_specular);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_albedo_specular);
-    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA, screen_x, screen_y, 0);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT2, GL_TEXTURE_2D_MULTISAMPLE, g_albedo_specular, 0);
-    glCheckError();
-    
-    // - tell OpenGL which color attachments we'll use (of this framebuffer) for rendering 
-    unsigned int attachments[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
-    glDrawBuffers(3, attachments);
-    glCheckError();
-
-    create_out_buffers();
-
-  if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
-    throw std::runtime_error("Error creating G buffer.");
-  }
-    glBindTexture(GL_TEXTURE_2D, 0);
-
-  }
-
-  void bind() {
-    glActiveTexture(GL_TEXTURE0);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_position);
-    glActiveTexture(GL_TEXTURE1);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_normal);
-    glActiveTexture(GL_TEXTURE2);
-    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, g_albedo_specular);
-    }
-
-
-  void present(std::shared_ptr<shader_handle> deferred_lighting, GLuint quad_vao) {
-
-    glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
-    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, g_buffer_out.fbo);
-    glBlitFramebuffer(0,0,width, height, 0,0,width,height, GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT, GL_NEAREST);
-    g_buffer_out.bind_textures();
-    g_buffer_out.present(deferred_lighting, quad_vao);
-  }
-
-};
 
 void move_player(game_state &g, glm::vec3 walking_state, float time_delta) { 
 
@@ -422,6 +313,12 @@ int main_loop(game_state& g)
   SDL_Event e;
   bool quit = false;
 
+  struct {
+    float exposure = 1.0;
+    float gamma = 2.2;
+    bool use_hdr = false;
+  } tone_mapping;
+
   glCheckError();
   glClearColor(0.0F, 0.0F, 0.0F, 1.0F);
   glDisable(GL_CULL_FACE);
@@ -439,7 +336,8 @@ int main_loop(game_state& g)
                                       g.asset_dir / "shaders" / "g_frag.gl");
   auto forward_pass_shader = g_shader;
 
-  struct g_buffer G {g.render_target->width, g.render_target->height};
+  // set scaling
+  struct g_buffer G {g.render_target->width, g.render_target->height, 1.0f}; // scaling 1x
   glCheckError();
   G.create_buffers();
   glCheckError();
@@ -586,12 +484,13 @@ int main_loop(game_state& g)
 
 
     if (deferred) {
-      glBindFramebuffer(GL_FRAMEBUFFER, G.fbo);
+      glBindFramebuffer(GL_DRAW_FRAMEBUFFER, G.fbo);
+      glViewport(0,0,G.logical_width, G.logical_height);
       G.bind_textures();
       forward_pass_shader = g_shader;
     } else {
       forward_pass_shader = forward_lighting;
-      glBindFramebuffer(GL_FRAMEBUFFER, 0);
+      g.render_target->bind();
     }
 
     forward_pass_shader->use();
@@ -658,7 +557,7 @@ int main_loop(game_state& g)
       xenia_transform = glm::translate(xenia_transform, parent_transform.position);
       xenia_transform = glm::translate(xenia_transform, glm::vec3(0, -8, 0));
       xenia_transform = glm::rotate(xenia_transform, (float)M_PI, glm::vec3(1,0,0));
-      xenia_transform = glm::rotate(xenia_transform, (float)M_PI/2 - (glm::radians(cam.euler_angles[0] * walking_state.z) - glm::radians(90 * walking_state.x)), glm::vec3(0,1,0));
+      xenia_transform = glm::rotate(xenia_transform, (float)M_PI/2 - (glm::radians(cam.euler_angles[0] * walking_state.z) - glm::radians((cam.euler_angles[0] + 90) * walking_state.x)), glm::vec3(0,1,0));
       xenia_transform = glm::scale(xenia_transform, glm::vec3(0.5));
       xenia.draw(mat_ubo, model_ubo, forward_pass_shader, xenia_transform);
 
@@ -696,10 +595,10 @@ int main_loop(game_state& g)
     glCheckError();
 
     if (deferred) {
+      g.render_target->bind();
       // now draw the g buffer into the final buffer 
       //g.render_target->present(g.screen_shader);
-      glBindFramebuffer(GL_FRAMEBUFFER, 0);
-      glDisable(GL_DEPTH_TEST);
+      //glBindFramebuffer(GL_FRAMEBUFFER, 0);
       //g.screen_shader->use();
       // now execute deferred lighting shader
       deferred_lighting->use();
@@ -709,6 +608,7 @@ int main_loop(game_state& g)
       G.present(deferred_lighting, g.platonic_shapes.quad_vao);
     }
 
+    g.render_target->present(g.screen_shader);
     // forward render imgui on top of the scene
     ImGui::Begin("Trees");
     ImGui::SliderInt("Num Lights", &num_lights, 1, max_lights);
@@ -718,6 +618,9 @@ int main_loop(game_state& g)
     ImGui::Checkbox("Enable fog", (bool *)&fog_enabled);
     ImGui::Checkbox("Move lights", (bool *)&move_lights);
     ImGui::Checkbox("Deferred Shading", (bool *)&deferred);
+    ImGui::Checkbox("HDR", (bool *)&tone_mapping.use_hdr);
+    ImGui::SliderFloat("Exposure", &tone_mapping.exposure, 0, 3.0);
+    ImGui::SliderFloat("Gamma", &tone_mapping.gamma, 0, 4.0);
     ImGui::Combo("Debug shader", &debug_shader, debug_shaders, IM_ARRAYSIZE(debug_shaders));
     ImGui::End();
     ImGui::Render();
@@ -725,6 +628,9 @@ int main_loop(game_state& g)
     SDL_GL_SwapWindow(g.window);
     mat_ubo->current_lights(num_lights);
     mat_ubo->enable_fog(fog_enabled);
+    g.screen_shader->set("gamma", tone_mapping.gamma);
+    g.screen_shader->set("exposure", tone_mapping.exposure);
+    g.screen_shader->set("use_hdr", tone_mapping.use_hdr);
 
     while (SDL_PollEvent(&e) != 0) {
       ImGui_ImplSDL2_ProcessEvent(&e);

source/window.cpp

@@ -129,7 +129,7 @@ void game_state::init_renderbuffer()
       std::make_shared<shader_handle>(asset_dir / "shaders" / "screen.vert",
                                       asset_dir / "shaders" / "screen.frag");
   screen_shader->use();
-  screen_shader->set("screenTexture", 0);
+  screen_shader->set("screenTexture", 4);
 
   glCheckError();
 }
@@ -137,12 +137,14 @@ void game_state::init_renderbuffer()
 void framebuffer_render_context::bind() const
 {
   glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+  glViewport(0,0, width, height);
   glCheckError();
 }
 
 void framebuffer_render_context::unbind() const
 {
   glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  glViewport(0,0, width, height);
   glCheckError();
 }
 
@@ -167,9 +169,11 @@ void framebuffer_render_context::clear()
 void framebuffer_render_context::present(std::shared_ptr<shader_handle>& shader)
 {
   glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
   glDisable(GL_DEPTH_TEST);
   shader->use();
   glBindVertexArray(quad_vao);
+  glActiveTexture(GL_TEXTURE4);
   glBindTexture(GL_TEXTURE_2D, colour);
   glDrawArrays(GL_TRIANGLES, 0, 6);
   glCheckError();