Update uniform handling

CHANGELOG.md

@@ -0,0 +1,3 @@
+## [v0.1.1] - 2024-08-25
+### Changed
+- Refactored uniform handling in the initial geometry pass to improve maintainability.

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.10)
-project(TerraVisor VERSION 0.0.1)
+project(TerraVisor VERSION 0.0.2)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)

include/uniforms.h

@@ -2,6 +2,7 @@
 
 #include <GL/glew.h>
 #include <glm/glm.hpp>
+#include <string>
 
 namespace Uniforms
 {
@@ -15,6 +16,17 @@ namespace Uniforms
         glm::vec4 eye_w = glm::vec4(0.0f, 0.0f, 3.0f, 1.0f);	//world-space eye position
     };
 
+    struct GeoUniforms
+    {
+        glm::mat4 PV;
+        glm::mat4 M;
+        
+        float minTessellation =     1.0f;
+        float maxTessellation =     32.0f;
+        float displacementScale =   0.007f;
+        int gridDensity =           16;
+    };
+
     struct LightUniforms
     {
         glm::vec4 La = glm::vec4(0.5f, 0.5f, 0.55f, 1.0f);	//ambient light color
@@ -34,11 +46,13 @@ namespace Uniforms
     extern SceneUniforms SceneData;
     extern LightUniforms LightData;
     extern MaterialUniforms MaterialData;
+    extern GeoUniforms GeoData;
 
     //IDs for the buffer objects holding the uniform block data
-    extern GLuint scene_ubo;
+    extern GLuint sceneUbo;
-    extern GLuint light_ubo;
+    extern GLuint lightUbo;
-    extern GLuint material_ubo;
+    extern GLuint materialUbo;
+    extern GLuint geoUbo;
 
     namespace UboBinding
     {
@@ -46,6 +60,7 @@ namespace Uniforms
         extern int scene;
         extern int light;
         extern int material;
+        extern int geo;
     };
 
     //Locations for the uniforms which are not in uniform blocks

shaders/fragment.glsl

@@ -9,12 +9,6 @@ in TE_OUT {
     vec3 normal;
 } fs_in;
 
-layout(std140, binding = 0) uniform SceneUniforms
-{
-    mat4 PV;	//camera projection * view matrix
-    vec4 eye_w;	//world-space eye position
-};
-
 layout(location = 0) out vec4 albedoGbuffer;
 layout(location = 1) out vec4 positionGbuffer;
 layout(location = 2) out vec4 normalGbuffer;

shaders/tessellation_ctrl.glsl

@@ -2,6 +2,20 @@
 
 layout(vertices = 4) out;
 
+layout(binding = 0) uniform sampler2D heightTexture;
+uniform float tessellationFactor;
+
+layout(std140, binding = 4) uniform GeoUniforms
+{
+    mat4 PV;
+    mat4 M;
+    
+    float minTessellation;
+    float maxTessellation;
+    float displacementScale;
+    int gridDensity;
+};
+
 in VS_OUT {
     vec3 position;
     vec2 texCoord;
@@ -12,21 +26,19 @@ out TC_OUT {
     vec2 texCoord;
 } tc_out[];
 
-uniform float tessellationFactor;
-
 void main() {
-    // Set tessellation levels
-    if (gl_InvocationID == 0) {
-        gl_TessLevelOuter[0] = tessellationFactor; // Level of tessellation along one edge
-        gl_TessLevelOuter[1] = tessellationFactor; // Level of tessellation along another edge
-        gl_TessLevelOuter[2] = tessellationFactor; // Level of tessellation along the other edge
-        gl_TessLevelOuter[3] = tessellationFactor; // Level of tessellation along the other edge
-
-        gl_TessLevelInner[0] = tessellationFactor; // Level of tessellation for the inner part
-        gl_TessLevelInner[1] = tessellationFactor; // Level of tessellation for the inner part
-    }
-
     // Pass through position and texture coordinates to the tessellation evaluation shader
     tc_out[gl_InvocationID].position = tc_in[gl_InvocationID].position;
     tc_out[gl_InvocationID].texCoord = tc_in[gl_InvocationID].texCoord;
+
+    // Set tessellation levels
+    if (gl_InvocationID == 0) {
+        gl_TessLevelOuter[0] = maxTessellation; 
+        gl_TessLevelOuter[1] = maxTessellation; 
+        gl_TessLevelOuter[2] = maxTessellation; 
+        gl_TessLevelOuter[3] = maxTessellation; 
+
+        gl_TessLevelInner[0] = maxTessellation; 
+        gl_TessLevelInner[1] = maxTessellation; 
+    }
 }

shaders/tessellation_eval.glsl

@@ -3,15 +3,16 @@
 layout(quads, fractional_even_spacing, cw) in;
 
 layout(binding = 0) uniform sampler2D heightTexture;
-layout(location = 0) uniform mat4 M;
 
-uniform float displacementScale = 0.025f;
+layout(std140, binding = 4) uniform GeoUniforms
-uniform float tessellationFactor;
-
-layout(std140, binding = 0) uniform SceneUniforms
 {
-    mat4 PV;	//camera projection * view matrix
+    mat4 PV;
-    vec4 eye_w;	//world-space eye position
+    mat4 M;
+    
+    float minTessellation;
+    float maxTessellation;
+    float displacementScale;
+    int gridDensity;
 };
 
 in TC_OUT {
@@ -30,13 +31,16 @@ float getHeight(vec2 uv) {
 }
 
 vec3 calculateSmoothNormal(vec3 pos, vec2 coord) {
-    float step = 1.0f / (16.0f * tessellationFactor + 1.0f);
+    // Currently hardcoded to match patch density
+    float step = 1.0f / (float(gridDensity) * maxTessellation + 1.0f);
 
+    // Find surrounding heights
     float hLeft = getHeight(coord + vec2(-step, 0.0f));
     float hRight = getHeight(coord + vec2(step, 0.0f));
     float hUp = getHeight(coord + vec2(0.0f, step));
     float hDown = getHeight(coord + vec2(0.0f, -step));
     
+    // Calculate tangents
     vec3 tangentX = normalize(vec3(step, hRight - hLeft, 0.0));
     vec3 tangentY = normalize(vec3(0.0, hUp - hDown, step));
 

shaders/vertex.glsl

@@ -1,7 +1,7 @@
 #version 450 core
 
-layout(location = 0) in vec3 inPosition;
+layout(location = 0) in vec3 posAttrib;
-layout(location = 1) in vec2 inTexCoord;
+layout(location = 1) in vec2 texCoordAttrib;
 
 out VS_OUT {
     vec3 position;
@@ -9,6 +9,6 @@ out VS_OUT {
 } vs_out;
 
 void main() {
-    vs_out.position = (vec4(inPosition, 1.0f)).xyz;
+    vs_out.position = (vec4(posAttrib, 1.0f)).xyz;
-    vs_out.texCoord = inTexCoord;
+    vs_out.texCoord = texCoordAttrib;
 }

source/InitShader.cpp

@@ -160,13 +160,13 @@ GLuint InitShader(const char* vShaderFile, const char* fShaderFile)
     }
 
     //set shader attrib locations
-   const int pos_loc = 0;
+    const int posLoc = 0;
-   const int tex_coord_loc = 1;
+    const int texCoordLoc = 1;
-   const int normal_loc = 2;
+    const int normalLoc = 2;
 
-   glBindAttribLocation(program, pos_loc, "pos_attrib");
+    glBindAttribLocation(program, posLoc, "posAttrib");
-   glBindAttribLocation(program, tex_coord_loc, "tex_coord_attrib");
+    glBindAttribLocation(program, texCoordLoc, "texCoordAttrib");
-   glBindAttribLocation(program, normal_loc, "normal_attrib");
+    glBindAttribLocation(program, normalLoc, "normalAttrib");
 
     /* link  and error check */
     glLinkProgram(program);
@@ -238,13 +238,13 @@ GLuint InitShader(const char* vShaderFile, const char* gShaderFile, const char*
     }
 
     //set shader attrib locations
-   const int pos_loc = 0;
+    const int posLoc = 0;
-   const int tex_coord_loc = 1;
+    const int texCoordLoc = 1;
-   const int normal_loc = 2;
+    const int normalLoc = 2;
 
-   glBindAttribLocation(program, pos_loc, "pos_attrib");
+    glBindAttribLocation(program, posLoc, "posAttrib");
-   glBindAttribLocation(program, tex_coord_loc, "tex_coord_attrib");
+    glBindAttribLocation(program, texCoordLoc, "texCoordAttrib");
-   glBindAttribLocation(program, normal_loc, "normal_attrib");
+    glBindAttribLocation(program, normalLoc, "normalAttrib");
 
     /* link  and error check */
     glLinkProgram(program);
@@ -315,6 +315,13 @@ GLuint InitShader( const char* vShaderFile, const char* tcShader, const char* te
         glAttachShader( program, shader );
     }
 
+    //set shader attrib locations
+    const int posLoc = 0;
+    const int texCoordLoc = 1;
+
+    glBindAttribLocation(program, posLoc, "posAttrib");
+    glBindAttribLocation(program, texCoordLoc, "texCoordAttrib");
+
     /* link  and error check */
     glLinkProgram(program);
 

source/scene.cpp

@@ -25,7 +25,7 @@
 
 #include "scene.h"
 #include "camera.h"
-#include "Uniforms.h"
+#include "uniforms.h"
 #include "InitShader.h" 
 #include "DebugCallback.h"
 #include "load_texture.h"
@@ -139,7 +139,7 @@ void Scene::GenerateGrid(int divisions, std::vector<Vertex>& verts, std::vector<
 
 // Currently creates a test triangle and initializes its buffers
 void Scene::InitBuffers() {
-    int divisions = 16;  // Number of divisions along one axis of the grid
+    int divisions = Uniforms::GeoData.gridDensity;  // Number of divisions along one axis of the grid
     GenerateGrid(divisions, vertices, indices);
 
     // Create and bind VAO, VBO, and EBO, and pass the data to OpenGL
@@ -225,11 +225,10 @@ void Scene::Display(GLFWwindow* window) {
 
     //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 
-    Uniforms::SceneData.PV = projection_matrix_ * CameraControls::GetViewMatrix(activeCamera_); // Projection-View matrix
+    Uniforms::GeoData.PV = projection_matrix_ * CameraControls::GetViewMatrix(activeCamera_); // Projection-View matrix
     Uniforms::BufferSceneData();
 
-    glm::mat4 model_matrix = glm::rotate(angle_, glm::vec3(1.0f, 0.0f, 0.0f)) * glm::scale(glm::vec3(scale_));
+    Uniforms::GeoData.M = glm::rotate(angle_, glm::vec3(1.0f, 0.0f, 0.0f)) * glm::scale(glm::vec3(scale_));
-    glUniformMatrix4fv(Uniforms::UniformLocs::M, 1, false, glm::value_ptr(model_matrix));
 
     glActiveTexture(GL_TEXTURE0);
     glBindTexture(GL_TEXTURE_2D, tex_id);
@@ -336,7 +335,8 @@ void Scene::DrawGui(GLFWwindow* window) {
 
     ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
 
-    ImGui::SliderFloat("Tessellation Level", &tessellationFactor, 1.0f, 64.0f);
+    ImGui::SliderFloat("Tessellation Level", &Uniforms::GeoData.maxTessellation, 1.0f, 64.0f);
+    ImGui::SliderInt("Patch Grid Density", &Uniforms::GeoData.gridDensity, 1, 24);
     ImGui::End();
 
     // Draw FBO to ImGui window

source/uniforms.cpp

@@ -1,4 +1,4 @@
-#include "Uniforms.h"
+#include "uniforms.h"
 #include <GL/glew.h>
 
 namespace Uniforms
@@ -6,11 +6,13 @@ namespace Uniforms
     SceneUniforms SceneData;
     LightUniforms LightData;
     MaterialUniforms MaterialData;
+    GeoUniforms GeoData;
 
     //IDs for the buffer objects holding the uniform block data
-    GLuint scene_ubo = -1;
+    GLuint sceneUbo = 0;
-    GLuint light_ubo = -1;
+    GLuint lightUbo = 0;
-    GLuint material_ubo = -1;
+    GLuint materialUbo = 0;
+    GLuint geoUbo = 0;
 
     namespace UboBinding
     {
@@ -18,6 +20,7 @@ namespace Uniforms
         int scene = 0;
         int light = 1;
         int material = 2;
+        int geometry = 4;
     };
 
     //Locations for the uniforms which are not in uniform blocks
@@ -30,28 +33,37 @@ namespace Uniforms
     void Init()
     {
         //Create and initialize uniform buffers
-        glGenBuffers(1, &Uniforms::scene_ubo);
+        glGenBuffers(1, &Uniforms::sceneUbo);
-        glBindBuffer(GL_UNIFORM_BUFFER, scene_ubo);
+        glBindBuffer(GL_UNIFORM_BUFFER, sceneUbo);
         glBufferData(GL_UNIFORM_BUFFER, sizeof(SceneUniforms), nullptr, GL_STREAM_DRAW); //Allocate memory for the buffer, but don't copy (since pointer is null).
-        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::scene, scene_ubo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
+        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::scene, sceneUbo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
 
-        glGenBuffers(1, &light_ubo);
+        glGenBuffers(1, &lightUbo);
-        glBindBuffer(GL_UNIFORM_BUFFER, light_ubo);
+        glBindBuffer(GL_UNIFORM_BUFFER, lightUbo);
         glBufferData(GL_UNIFORM_BUFFER, sizeof(LightUniforms), &LightData, GL_STREAM_DRAW); //Allocate memory for the buffer, but don't copy (since pointer is null).
-        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::light, light_ubo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
+        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::light, lightUbo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
 
-        glGenBuffers(1, &material_ubo);
+        glGenBuffers(1, &materialUbo);
-        glBindBuffer(GL_UNIFORM_BUFFER, material_ubo);
+        glBindBuffer(GL_UNIFORM_BUFFER, materialUbo);
         glBufferData(GL_UNIFORM_BUFFER, sizeof(MaterialUniforms), &MaterialData, GL_STREAM_DRAW); //Allocate memory for the buffer, but don't copy (since pointer is null).
-        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::material, material_ubo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
+        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::material, materialUbo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
+
+        glGenBuffers(1, &geoUbo);
+        glBindBuffer(GL_UNIFORM_BUFFER, geoUbo);
+        glBufferData(GL_UNIFORM_BUFFER, sizeof(GeoUniforms), &GeoData, GL_STREAM_DRAW); //Allocate memory for the buffer, but don't copy (since pointer is null).
+        glBindBufferBase(GL_UNIFORM_BUFFER, UboBinding::geometry, geoUbo); //Associate this uniform buffer with the uniform block in the shader that has the same binding.
 
         glBindBuffer(GL_UNIFORM_BUFFER, 0);
     }
 
     void BufferSceneData()
     {
-        glBindBuffer(GL_UNIFORM_BUFFER, scene_ubo); //Bind the OpenGL UBO before we update the data.
+        glBindBuffer(GL_UNIFORM_BUFFER, sceneUbo); //Bind the OpenGL UBO before we update the data.
         glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(SceneData), &SceneData); //Upload the new uniform values.
         glBindBuffer(GL_UNIFORM_BUFFER, 0); //unbind the ubo
+
+        glBindBuffer(GL_UNIFORM_BUFFER, geoUbo); //Bind the OpenGL UBO before we update the data.
+        glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(GeoData), &GeoData); //Upload the new uniform values.
+        glBindBuffer(GL_UNIFORM_BUFFER, 0); //unbind the ubo
     }
 };