From 517ffdf8b26772bfccd4d7bf95cb07be1bae650e Mon Sep 17 00:00:00 2001
From: Joseph Walton-Rivers <joseph@walton-rivers.uk>
Date: Sat, 17 Jul 2021 23:22:43 +0100
Subject: [PATCH] first attempt at lighting
---
build.sh | 3 ++
demo/data/normals_frag.glsl | 9 ++++++
demo/data/normals_geom.glsl | 30 +++++++++++++++++
demo/data/normals_vert.glsl | 18 +++++++++++
demo/data/phong_frag.glsl | 42 ++++++++++++++++++++++++
demo/data/phong_normals_frag.glsl | 41 ++++++++++++++++++++++++
demo/data/phong_vert.glsl | 34 ++++++++++++++++++++
demo/main.cpp | 53 ++++++++++++++++++++++++++++---
fggl/data/procedural.cpp | 53 +++++++++++++++++++++++++++++++
fggl/gfx/renderer.cpp | 8 +++++
fggl/gfx/shader.cpp | 2 +-
11 files changed, 287 insertions(+), 6 deletions(-)
create mode 100644 demo/data/normals_frag.glsl
create mode 100644 demo/data/normals_geom.glsl
create mode 100644 demo/data/normals_vert.glsl
create mode 100644 demo/data/phong_frag.glsl
create mode 100644 demo/data/phong_normals_frag.glsl
create mode 100644 demo/data/phong_vert.glsl
diff --git a/build.sh b/build.sh
index 3c5eda8..b9b5e31 100755
--- a/build.sh
+++ b/build.sh
@@ -6,6 +6,9 @@ then
mkdir build
fi
+# if doing shader development, disable the cache to make sure changes take affect
+rm -rf /tmp/fggl/
+
pushd build
cmake ..
make
diff --git a/demo/data/normals_frag.glsl b/demo/data/normals_frag.glsl
new file mode 100644
index 0000000..fe2187e
--- /dev/null
+++ b/demo/data/normals_frag.glsl
@@ -0,0 +1,9 @@
+#version 330 core
+// credit: https://learnopengl.com/Advanced-OpenGL/Geometry-Shader
+out vec4 FragColor;
+
+void main()
+{
+ FragColor = vec4(1.0, 1.0, 0.0, 1.0);
+}
+
diff --git a/demo/data/normals_geom.glsl b/demo/data/normals_geom.glsl
new file mode 100644
index 0000000..6f1aa16
--- /dev/null
+++ b/demo/data/normals_geom.glsl
@@ -0,0 +1,30 @@
+#version 330 core
+// credit: https://learnopengl.com/Advanced-OpenGL/Geometry-Shader
+
+layout (triangles) in;
+layout (line_strip, max_vertices = 6) out;
+
+in VS_OUT {
+ vec3 normal;
+} gs_in[];
+
+const float MAGNITUDE = 0.4;
+
+uniform mat4 projection;
+
+void GenerateLine(int index)
+{
+ gl_Position = projection * gl_in[index].gl_Position;
+ EmitVertex();
+ gl_Position = projection * (gl_in[index].gl_Position +
+ vec4(gs_in[index].normal, 0.0) * MAGNITUDE);
+ EmitVertex();
+ EndPrimitive();
+}
+
+void main()
+{
+ GenerateLine(0); // first vertex normal
+ GenerateLine(1); // second vertex normal
+ GenerateLine(2); // third vertex normal
+}
diff --git a/demo/data/normals_vert.glsl b/demo/data/normals_vert.glsl
new file mode 100644
index 0000000..36a36b7
--- /dev/null
+++ b/demo/data/normals_vert.glsl
@@ -0,0 +1,18 @@
+#version 330 core
+// credit: https://learnopengl.com/Advanced-OpenGL/Geometry-Shader
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+
+out VS_OUT {
+ vec3 normal;
+} vs_out;
+
+uniform mat4 view;
+uniform mat4 model;
+
+void main()
+{
+ gl_Position = view * model * vec4(aPos, 1.0);
+ mat3 normalMatrix = mat3(transpose(inverse(view * model)));
+ vs_out.normal = normalize(vec3(vec4(normalMatrix * aNormal, 0.0)));
+}
diff --git a/demo/data/phong_frag.glsl b/demo/data/phong_frag.glsl
new file mode 100644
index 0000000..0d4df5e
--- /dev/null
+++ b/demo/data/phong_frag.glsl
@@ -0,0 +1,42 @@
+#version 330 core
+// based on http://www.opengl-tutorial.org, WTFPL
+
+
+uniform vec3 lightPos;
+
+in vec3 normal;
+
+in vec3 pos_ws;
+in vec3 normal_cs;
+in vec3 lightdir_cs;
+in vec3 eyedir_cs;
+
+out vec4 FragColor;
+
+void main()
+{
+ vec3 lightColour = vec3( 1.0, 1.0, 1.0 );
+ vec3 objColour = vec3(1.0f, 0.6f, 0.2f);
+ float lightPower = 200.0;
+
+ // material colours
+ vec3 matDiff = vec3(1.0, 0.6, 0.2 );
+ vec3 matAmb = vec3(0.1) * matDiff;
+ vec3 matSpec = vec3(0.3);
+
+ vec3 n = normalize( normal_cs );
+ vec3 l = normalize( lightdir_cs );
+ float distance = length( lightPos - pos_ws );
+
+ vec3 e = normalize( eyedir_cs );
+ vec3 r = reflect( -l, n );
+ float cosAlpha = clamp( dot(e, r), 0, 1);
+
+ float cosTheta = clamp( dot( n, l ), 0, 1 );
+ vec3 colour =
+ ( matAmb ) +
+ ( matDiff * lightColour * lightPower * cosTheta / ( distance*distance ) ) +
+ ( matSpec * lightColour * lightPower * pow( cosAlpha, 5 ) / (distance*distance) );
+
+ FragColor = vec4(colour, 1);
+}
diff --git a/demo/data/phong_normals_frag.glsl b/demo/data/phong_normals_frag.glsl
new file mode 100644
index 0000000..f39c8fc
--- /dev/null
+++ b/demo/data/phong_normals_frag.glsl
@@ -0,0 +1,41 @@
+#version 330 core
+// based on http://www.opengl-tutorial.org, WTFPL
+
+uniform vec3 lightPos;
+
+in vec3 normal;
+
+in vec3 pos_ws;
+in vec3 normal_cs;
+in vec3 lightdir_cs;
+in vec3 eyedir_cs;
+
+out vec4 FragColor;
+
+void main()
+{
+ vec3 lightColour = vec3( 1.0, 1.0, 1.0 );
+ vec3 objColour = vec3(1.0f, 0.6f, 0.2f);
+ float lightPower = 50.0;
+
+ // material colours
+ vec3 matDiff = vec3(1.0, 0.6, 0.2 );
+ vec3 matAmb = vec3(0.1) * matDiff;
+ vec3 matSpec = vec3(0.3);
+
+ vec3 n = normalize( normal_cs );
+ vec3 l = normalize( lightdir_cs );
+ float distance = length( lightPos - pos_ws );
+
+ vec3 e = normalize( eyedir_cs );
+ vec3 r = reflect( -l, n );
+ float cosAlpha = clamp( dot(e, r), 0, 1);
+
+ float cosTheta = clamp( dot( n, l ), 0, 1 );
+// vec3 colour =
+// ( matAmb ) +
+// ( matDiff * lightColour * lightPower * cosTheta / ( distance*distance ) ) +
+// ( matSpec * lightColour * lightPower * pow( cosAlpha, 5 ) / (distance*distance) );
+
+ FragColor = vec4(normal, 1);
+}
diff --git a/demo/data/phong_vert.glsl b/demo/data/phong_vert.glsl
new file mode 100644
index 0000000..c4a5f69
--- /dev/null
+++ b/demo/data/phong_vert.glsl
@@ -0,0 +1,34 @@
+#version 330 core
+// based on http://www.opengl-tutorial.org, WTFPL
+
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec3 aNormal;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+uniform vec3 lightPos;
+
+out vec3 normal;
+
+out vec3 pos_ws;
+out vec3 normal_cs;
+out vec3 lightdir_cs;
+out vec3 eyedir_cs;
+
+void main()
+{
+ gl_Position = projection * view * model * vec4(aPos, 1.0);
+ normal = aNormal;
+
+ // world space
+ pos_ws = ( model * vec4( aPos, 1 ) ).xyz;
+
+ // camera space
+ vec3 pos_cs = ( view * model * vec4(aPos, 1) ).xyz;
+ eyedir_cs = vec3(0, 0, 0) - pos_cs;
+
+ vec3 light_cs = ( view * vec4( lightPos, 1) ).xyz;
+ lightdir_cs = light_cs + eyedir_cs;
+ normal_cs = ( view * model * vec4( aNormal, 0 ) ).xyz;
+}
diff --git a/demo/main.cpp b/demo/main.cpp
index a5a4561..324c1ac 100644
--- a/demo/main.cpp
+++ b/demo/main.cpp
@@ -1,4 +1,5 @@
#include <filesystem>
+#include <glm/trigonometric.hpp>
#include <iostream>
#include <fggl/gfx/window.hpp>
@@ -61,28 +62,46 @@ int main(int argc, char* argv[]) {
config.fragment = "unlit_frag.glsl";
auto shader = cache.load(config);
+ fggl::gfx::ShaderConfig configPhong;
+ configPhong.name = "phong";
+ configPhong.vertex = configPhong.name + "_vert.glsl";
+ configPhong.fragment = configPhong.name + "_frag.glsl";
+// configPhong.fragment = configPhong.name + "_normals_frag.glsl";
+ auto shaderPhong = cache.load(configPhong);
+
+ fggl::gfx::ShaderConfig configNormals;
+ configNormals.name = "normals";
+ configNormals.hasGeom = true;
+ configNormals.vertex = configNormals.name + "_vert.glsl";
+ configNormals.geometry = configNormals.name + "_geom.glsl";
+ configNormals.fragment = configNormals.name + "_frag.glsl";
+ auto shaderNormals = cache.load( configNormals );
+
// create ECS
fggl::ecs::ECS ecs;
ecs.registerComponent<fggl::gfx::MeshToken>();
ecs.registerComponent<fggl::math::Transform>();
- for (int i=0; i<3; i++) {
+ int nCubes = 3;
+ int nSlopes = 3;
+
+ for (int i=0; i<nCubes; i++) {
// create an entity
auto entity = ecs.createEntity();
// set the position
auto result = ecs.addComponent<fggl::math::Transform>(entity);
- result->origin( glm::vec3( 0.0f, 0.0f, i * -1.0f) );
+ result->origin( glm::vec3( 0.0f, 0.0f, i * -1.0f) );
// in a supprise to no one it's a triangle
auto mesh = fggl::data::make_cube();
auto token = meshRenderer.upload(mesh);
- token.pipeline = shader;
+ token.pipeline = shaderNormals;
ecs.addComponent<fggl::gfx::MeshToken>(entity, token);
}
constexpr float HALF_PI = M_PI / 2.0f;
- for (int i=0; i<3; i++) {
+ for (int i=0; i<nSlopes; i++) {
// create an entity
auto entity = ecs.createEntity();
@@ -94,20 +113,44 @@ int main(int argc, char* argv[]) {
// in a supprise to no one it's a triangle
auto mesh = fggl::data::make_slope();
auto token = meshRenderer.upload(mesh);
- token.pipeline = shader;
+ token.pipeline = shaderNormals;
ecs.addComponent<fggl::gfx::MeshToken>(entity, token);
}
+ float time = 0.0f;
+ float dt = 16.0f;
while( !win.closeRequested() ) {
ctx.pollEvents();
debug.frameStart();
// update step
+ time += dt;
+
+/* float amount = glm::radians( time / 2048.0f * 360.0f );
+ auto spinners = ecs.getEntityWith<fggl::math::Transform>();
+ for ( auto entity : spinners ) {
+ auto transform = ecs.getComponent<fggl::math::Transform>(entity);
+ transform->euler(glm::vec3(0.0f, amount, 0.0f));
+ }*/
// render step
ogl.clear();
+
+ // render using real shader
+ auto renderables = ecs.getEntityWith<fggl::gfx::MeshToken>();
+ for ( auto renderable : renderables ) {
+ auto token = ecs.getComponent<fggl::gfx::MeshToken>(renderable);
+ token->pipeline = shaderPhong;
+ }
meshRenderer.render(win, ecs, 16.0f);
+ // render using normals shader
+ /*for ( auto renderable : renderables ) {
+ auto token = ecs.getComponent<fggl::gfx::MeshToken>(renderable);
+ token->pipeline = shaderNormals;
+ }
+ meshRenderer.render(win, ecs, 16.0f);*/
+
debug.draw();
win.swap();
}
diff --git a/fggl/data/procedural.cpp b/fggl/data/procedural.cpp
index e9a7e82..35c26de 100644
--- a/fggl/data/procedural.cpp
+++ b/fggl/data/procedural.cpp
@@ -1,9 +1,43 @@
#include "procedural.hpp"
#include "model.hpp"
+#include <glm/geometric.hpp>
using namespace fggl::data;
+// from https://www.khronos.org/opengl/wiki/Calculating_a_Surface_Normal
+static glm::vec3 calcSurfaceNormal(glm::vec3 a, glm::vec3 b, glm::vec3 c) {
+ glm::vec3 u = b - a;
+ glm::vec3 v = c - a;
+ return glm::normalize( glm::cross( u, v ) );
+}
+
+static void computeNormals( fggl::data::Mesh& mesh, const int* idx, const int* colIdx, int points) {
+
+ // we're assuming all the normals are zero...
+ for (auto& vertex : mesh.vertexList() ) {
+ vertex.normal = glm::vec3(0.0f);
+ }
+
+ // each vertex normal should be the sum of the triangles it's part of.
+ for (int i=0; i<points; i += 3) {
+ auto& v1 = mesh.vertex( colIdx[ idx[i] ] );
+ auto& v2 = mesh.vertex( colIdx[ idx[i + 1] ] );
+ auto& v3 = mesh.vertex( colIdx[ idx[i + 2] ] );
+
+ v1.normal += calcSurfaceNormal( v1.posititon, v2.posititon, v3.posititon );
+ v2.normal += calcSurfaceNormal( v2.posititon, v3.posititon, v1.posititon );
+ v3.normal += calcSurfaceNormal( v3.posititon, v1.posititon, v2.posititon );
+// v3.normal += calcSurfaceNormal( v3.posititon, v1.posititon, v2.posititon );
+ }
+
+ // each vertex should currently be the sum of every triangle it's part of
+ // so we need to normalize them
+ for (auto& vertex : mesh.vertexList() ) {
+ vertex.normal = glm::normalize( vertex.normal );
+ }
+}
+
fggl::data::Mesh fggl::data::make_triangle() {
constexpr fggl::math::vec3 pos[]{
{-0.5f, -0.5f, 0.0f},
@@ -16,6 +50,7 @@ fggl::data::Mesh fggl::data::make_triangle() {
for (auto po : pos) {
Vertex vert{};
vert.posititon = po;
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
mesh.push(vert);
}
@@ -45,6 +80,7 @@ fggl::data::Mesh fggl::data::make_quad_xy() {
for (int i = 0; i < 4; ++i){
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex(vert);
}
@@ -73,6 +109,7 @@ fggl::data::Mesh fggl::data::make_quad_xz() {
for (int i = 0; i < 4; ++i){
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex(vert);
}
@@ -119,13 +156,17 @@ fggl::data::Mesh fggl::data::make_cube() {
for ( int i=0; i < 8; ++i ) {
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex( vert );
}
+ int tris = 0;
for ( auto i : idx ){
mesh.pushIndex( colIdx[i] );
+ tris++;
}
+ computeNormals( mesh, idx, colIdx, tris );
return mesh;
}
@@ -161,13 +202,17 @@ fggl::data::Mesh fggl::data::make_slope() {
for ( int i=0; i < 8; ++i ) {
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex( vert );
}
+ int tris = 0;
for ( auto i : idx ){
mesh.pushIndex( colIdx[i] );
+ tris++;
}
+ computeNormals( mesh, idx, colIdx, tris );
return mesh;
}
@@ -205,13 +250,17 @@ fggl::data::Mesh fggl::data::make_ditch() {
for ( int i=0; i < 8; ++i ) {
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex( vert );
}
+ int tris = 0;
for ( auto i : idx ){
mesh.pushIndex( colIdx[i] );
+ tris++;
}
+ computeNormals( mesh, idx, colIdx, tris );
return mesh;
}
@@ -244,13 +293,17 @@ fggl::data::Mesh fggl::data::make_point() {
for ( int i=0; i < 8; ++i ) {
Vertex vert{};
vert.posititon = pos[i];
+ vert.normal = glm::vec3(0.0f, 0.0f, 0.0f);
vert.colour = fggl::math::vec3(1.0f, 1.0f, 1.0f);
colIdx[ i ] = mesh.pushVertex( vert );
}
+ int tris = 0;
for ( auto i : idx ){
mesh.pushIndex( colIdx[i] );
+ tris++;
}
+ computeNormals( mesh, idx, colIdx, tris );
return mesh;
}
diff --git a/fggl/gfx/renderer.cpp b/fggl/gfx/renderer.cpp
index fe3e9d0..0a74213 100644
--- a/fggl/gfx/renderer.cpp
+++ b/fggl/gfx/renderer.cpp
@@ -74,6 +74,8 @@ void MeshRenderer::render(const Window& window, const fggl::ecs::ECS& ecs, float
glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);
+ glEnable(GL_DEPTH_TEST);
+
// make sure the correct rendering context is active
window.activate();
@@ -82,6 +84,7 @@ void MeshRenderer::render(const Window& window, const fggl::ecs::ECS& ecs, float
glm::mat4 view = glm::lookAt( glm::vec3 ( 0.0f, 3.0f, 3.0f ), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f) );
glm::mat4 proj = glm::perspective( glm::radians(45.0f), 1280.0f/720.0f, 0.1f, 100.0f);
+ glm::vec3 lightPos(20.0f, 20.0f, 15.0f);
// TODO better performance if grouped by vao first
// TODO the nvidia performance presentation said I shouldn't use uniforms for large data
@@ -99,6 +102,11 @@ void MeshRenderer::render(const Window& window, const fggl::ecs::ECS& ecs, float
glUniformMatrix4fv( glGetUniformLocation(shader, "view"), 1, GL_FALSE, glm::value_ptr( view ) );
glUniformMatrix4fv( glGetUniformLocation(shader, "projection"), 1, GL_FALSE, glm::value_ptr( proj ) );
+ // lighting
+ GLint lightID = glGetUniformLocation(shader, "lightPos");
+ if ( lightID != -1 )
+ glUniform3fv( lightID, 1, glm::value_ptr( lightPos ) );
+
glBindVertexArray( mesh->vao );
glDrawElements( GL_TRIANGLES, mesh->idxSize, GL_UNSIGNED_INT, reinterpret_cast<void*>(mesh->idxOffset) );
}
diff --git a/fggl/gfx/shader.cpp b/fggl/gfx/shader.cpp
index 7aa478c..144bfa7 100644
--- a/fggl/gfx/shader.cpp
+++ b/fggl/gfx/shader.cpp
@@ -110,7 +110,7 @@ GLuint ShaderCache::load(const ShaderConfig& config) {
GLuint geomShader;
if ( config.hasGeom ) {
geomShader = glCreateShader(GL_GEOMETRY_SHADER);
- compileShader( config.fragment, geomShader );
+ compileShader( config.geometry, geomShader );
glAttachShader(pid, geomShader);
}
--
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