From 4cf0dc230be536094671b6c3fd70ecbe40144b5d Mon Sep 17 00:00:00 2001
From: karl <karl.bittner@hexaquo.at>
Date: Sun, 30 May 2021 20:33:10 +0200
Subject: [PATCH] Add heightmap and apply it in tessellation shader

---
 Shader/terrain.fs       |  6 +++---
 Shader/terrain.tcs      |  8 ++++----
 Shader/terrain.tes      | 11 ++++++++++-
 Shader/terrain.vs       |  7 +------
 test/full-demo/main.cpp |  6 +++++-
 5 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/Shader/terrain.fs b/Shader/terrain.fs
index 804a588..1799ceb 100644
--- a/Shader/terrain.fs
+++ b/Shader/terrain.fs
@@ -5,11 +5,11 @@ in PipelineData {
     vec2 texture_coordinate;
 } fs_in;
 
-uniform sampler2D diffuse_texture;
+layout (binding = 0) uniform sampler2D heightmap;
 
 out vec4 color;
 
 void main() {
-    vec4 diffuse_texel = texture(diffuse_texture, fs_in.texture_coordinate);
-    color = vec4(1.0); // color = vec4(diffuse_texel);
+    vec4 diffuse_texel = texture(heightmap, fs_in.texture_coordinate);
+    color = vec4(diffuse_texel);
 }
\ No newline at end of file
diff --git a/Shader/terrain.tcs b/Shader/terrain.tcs
index ecd980d..f1a8659 100644
--- a/Shader/terrain.tcs
+++ b/Shader/terrain.tcs
@@ -16,8 +16,8 @@ void main() {
     tc_out[gl_InvocationID].texture_coordinate = tc_in[gl_InvocationID].texture_coordinate;
     tc_out[gl_InvocationID].position = tc_in[gl_InvocationID].position;
 
-    gl_TessLevelInner[0] = 12;
-    gl_TessLevelOuter[0] = 12;
-    gl_TessLevelOuter[1] = 12;
-    gl_TessLevelOuter[2] = 12;
+    gl_TessLevelInner[0] = 32;
+    gl_TessLevelOuter[0] = 32;
+    gl_TessLevelOuter[1] = 32;
+    gl_TessLevelOuter[2] = 32;
 }
\ No newline at end of file
diff --git a/Shader/terrain.tes b/Shader/terrain.tes
index 48509e3..b54b395 100644
--- a/Shader/terrain.tes
+++ b/Shader/terrain.tes
@@ -2,6 +2,12 @@
 
 layout(triangles) in;
 
+layout (binding = 0) uniform sampler2D heightmap;
+
+uniform mat4 model;
+uniform mat4 projection;
+uniform mat4 view;
+
 in PipelineData {
     vec4 position;
     vec2 texture_coordinate;
@@ -21,5 +27,8 @@ void main() {
     te_out.position += gl_TessCoord.y * te_in[1].position;
     te_out.position += gl_TessCoord.z * te_in[2].position;
 
-    gl_Position = te_out.position;
+    te_out.position.y += texture(heightmap, te_out.texture_coordinate).r;
+
+    mat4 pvm = projection * view * model;
+    gl_Position = pvm * te_out.position;
 }
\ No newline at end of file
diff --git a/Shader/terrain.vs b/Shader/terrain.vs
index a6f7e11..b2fce37 100644
--- a/Shader/terrain.vs
+++ b/Shader/terrain.vs
@@ -6,20 +6,15 @@ layout (location = 2) in vec2 texture_coordinate;
 layout (location = 3) in vec3 aTangent;
 layout (location = 4) in vec3 aBitangent;
 
-uniform mat4 model;
-uniform mat4 projection;
-uniform mat4 view;
-
 out PipelineData {
     vec4 position;
     vec2 texture_coordinate;
 } vs_out;
 
 void main() {
-    mat4 pvm = projection * view * model;
     vs_out.texture_coordinate = texture_coordinate;
     vec4 homogenous_position = vec4(position, 1.0);
-    vs_out.position = pvm * homogenous_position;
+    vs_out.position = homogenous_position;
 
     gl_Position = vs_out.position;
 }
\ No newline at end of file
diff --git a/test/full-demo/main.cpp b/test/full-demo/main.cpp
index 15b2102..09f2980 100644
--- a/test/full-demo/main.cpp
+++ b/test/full-demo/main.cpp
@@ -26,7 +26,8 @@ class FullDemo : public Gedeng::Application {
           particle_tex1("Resources/Textures/Particles/circle.png", Gedeng::Texture::Settings()),
           particle_tex2("Resources/Textures/Particles/magic.png", Gedeng::Texture::Settings()),
           particle_tex3("Resources/Textures/Particles/smoke.png", Gedeng::Texture::Settings()),
-          quad_mesh(Gedeng::QuadMesh(10.0)), light(glm::vec3(0.57735, -0.57735, 0.57735)),
+          heightmap("Resources/Textures/terrain.png", Gedeng::Texture::Settings()), quad_mesh(Gedeng::QuadMesh(10.0)),
+          light(glm::vec3(0.57735, -0.57735, 0.57735)),
           mesh1("Resources/Meshes/Monkey.obj", Gedeng::ObjMesh::Settings()),
           mesh2("Resources/Meshes/bench.obj", Gedeng::ObjMesh::Settings()),
           mesh3("Resources/Meshes/ring.obj", Gedeng::ObjMesh::Settings()) {
@@ -126,6 +127,7 @@ class FullDemo : public Gedeng::Application {
 
         // Terrain
         terrain_shader.use();
+        heightmap.bind_to(0);
         terrain_shader.setMat4("projection", camera.get_projection());
         terrain_shader.setMat4("view", camera.get_view());
         terrain_mesh.render_patches(terrain_shader);
@@ -157,6 +159,8 @@ class FullDemo : public Gedeng::Application {
     Gedeng::Texture particle_tex2;
     Gedeng::Texture particle_tex3;
 
+    Gedeng::Texture heightmap;
+
     Gedeng::QuadMesh quad_mesh;
     Gedeng::QuadMesh terrain_mesh;