Add multiple particle textures and more variety to types

Shader/particle_render.fs

@@ -1,13 +1,19 @@
 #version 430
 
-layout (binding = 0) uniform sampler2D texture;
+layout (binding = 0) uniform sampler2D texture1;
+layout (binding = 1) uniform sampler2D texture2;
+layout (binding = 2) uniform sampler2D texture3;
 
 smooth in vec2 tex_coords;
 flat in vec4 color_part;
+in float type;
 
 out vec4 FragColor;
 
 void main()
 {
-  FragColor = texture2D(texture, tex_coords) * color_part;
+  FragColor = texture2D(texture1, tex_coords) * color_part * float(abs(type - 1.0) < 0.1)
+   + texture2D(texture2, tex_coords) * color_part * float(abs(type - 2.0) < 0.1)
+   + texture2D(texture3, tex_coords) * color_part * float(abs(type - 3.0) < 0.1);
+
 }

Shader/particle_render.gs

@@ -17,11 +17,14 @@ in float type_pass[];
 
 smooth out vec2 tex_coords;
 flat out vec4 color_part;
+out float type;
 
 void main() {
   if(type_pass[0] != 0.0) {
     // This is not a generator particle
 
+    type = type_pass[0];
+
     vec3 old_pos = gl_in[0].gl_Position.xyz;
     float size = size_pass[0];
     mat4 view_projection_matrix = projection * view;

Shader/particle_update.gs

@@ -91,17 +91,17 @@ void main() {
       EndPrimitive(); 
   } else if (type_out == 1.0) {
     // The lifetime is over -- transform this particle in a new one or discard
-    for(int i = 0; i < 5; i++) {
+    for(int i = 0; i < 15; i++) {
       // Keep the position
-      velocity_out = spawn_velocity_min + vec3(
+      velocity_out = (spawn_velocity_min + vec3(
           spawn_velocity_range.x * random_zero_to_one(),
           spawn_velocity_range.y * random_zero_to_one(),
           spawn_velocity_range.z * random_zero_to_one()
-      );
+      )) * 0.75;
 
       color_out = vec3(1.0, 0, 0);
       lifetime_out = spawn_lifetime_min + spawn_lifetime_range * random_zero_to_one();
-      size_out = spawn_size;
+      size_out = spawn_size * 2.0;
       type_out = 2.0;
 
       EmitVertex();
@@ -109,17 +109,17 @@ void main() {
     } 
   } else if (type_out == 2.0) {
     // The lifetime is over -- transform this particle in a new one or discard
-    for(int i = 0; i < 5; i++) {
+    for(int i = 0; i < 10; i++) {
       // Keep the position
-      velocity_out = spawn_velocity_min + vec3(
+      velocity_out = (spawn_velocity_min + vec3(
           spawn_velocity_range.x * random_zero_to_one(),
           spawn_velocity_range.y * random_zero_to_one(),
           spawn_velocity_range.z * random_zero_to_one()
-      );
+      )) * 0.5;
 
       color_out = vec3(0.0, 1.0, 0);
-      lifetime_out = spawn_lifetime_min + spawn_lifetime_range * random_zero_to_one();
-      size_out = spawn_size;
+      lifetime_out = (spawn_lifetime_min + spawn_lifetime_range * random_zero_to_one()) * 0.3;
+      size_out = spawn_size * 0.75;
       type_out = 3.0;
 
       EmitVertex();

cpp/ParticleSystem.cpp

@@ -122,7 +122,9 @@ void ParticleSystem::render() {
     render_shader.setVec3("quad1", quad1);
     render_shader.setVec3("quad2", quad2);
 
-    texture->bind_to(0);
+    texture1->bind_to(0);
+    texture2->bind_to(1);
+    texture3->bind_to(2);
 
     glBindVertexArray(vao[current_read_buffer]);
     glDisableVertexAttribArray(1); // Disable velocity, because we don't need it for rendering
@@ -159,8 +161,10 @@ void ParticleSystem::set_interval(float interval) {
 void ParticleSystem::set_number_of_particles(int number) {
     this->target_particle_count = number;
 }
-void ParticleSystem::set_texture(Texture *texture) {
-    this->texture = texture;
+void ParticleSystem::set_textures(Texture *texture1, Texture *texture2, Texture *texture3) {
+    this->texture1 = texture1;
+    this->texture2 = texture2;
+    this->texture3 = texture3;
 }
 
 } // namespace Gedeng

cpp/Texture.cpp

@@ -37,8 +37,7 @@ uint Texture::load_texture(const std::string &path, Settings settings) {
         else if (nrChannels == 4)
             glChannels = GL_RGBA;
 
-        glTexImage2D(GL_TEXTURE_2D, 0, glChannels, width, height, 0, glChannels, GL_UNSIGNED_BYTE,
-                     data);
+        glTexImage2D(GL_TEXTURE_2D, 0, glChannels, width, height, 0, glChannels, GL_UNSIGNED_BYTE, data);
 
         if (settings.mipmaps) {
             glGenerateMipmap(GL_TEXTURE_2D);
@@ -57,4 +56,4 @@ void Texture::bind_to(int unit) {
     glBindTexture(GL_TEXTURE_2D, id);
 }
 
-}
+} // namespace Gedeng

include/Gedeng/ParticleSystem.h

@@ -30,7 +30,7 @@ class ParticleSystem {
     void set_size(float size);
     void set_interval(float interval);
     void set_number_of_particles(int number);
-    void set_texture(Texture *texture);
+    void set_textures(Texture *texture1, Texture *texture2, Texture *texture3);
 
     void clear();
     void release();
@@ -49,7 +49,9 @@ class ParticleSystem {
 
     GLuint query;
 
-    Texture *texture;
+    Texture *texture1;
+    Texture *texture2;
+    Texture *texture3;
 
     int current_read_buffer;
     int current_particle_count;

test/particle-demo/main.cpp

@@ -12,13 +12,16 @@ class ParticleApp : public Gedeng::Application {
   public:
     ParticleApp(unsigned long ms_per_update, unsigned int window_size_x, unsigned int window_size_y,
                 Gedeng::String window_name)
-        : Application(ms_per_update, window_size_x, window_size_y, window_name), particle_interval(0.1),
+        : Application(ms_per_update, window_size_x, window_size_y, window_name), particle_interval(0.2),
           number_of_steps(10.0), number_of_refinement_steps(10.0), bump_depth(0.1),
           render_shader(Gedeng::Shader("Shader/bump.vs", "Shader/bump.fs")),
           camera(Gedeng::FPSCamera(90, 1920, 1080, 0.1, 1000.0)),
           albedo("Resources/Textures/PavingStones/PavingStones070_2K_Color.jpg", Gedeng::Texture::Settings()),
           bump("Resources/Textures/PavingStones/PavingStones070_2K_Displacement.jpg", Gedeng::Texture::Settings()),
           normal("Resources/Textures/PavingStones/PavingStones070_2K_Normal.jpg", Gedeng::Texture::Settings()),
+          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)) {
         particles.set_position(glm::vec3(0.0f, 0.0f, -10.0f));
         particles.set_velocity(glm::vec3(-2, 4, -2), glm::vec3(2, 6, 2));
@@ -28,7 +31,7 @@ class ParticleApp : public Gedeng::Application {
         particles.set_size(0.1);
         particles.set_interval(particle_interval);
         particles.set_number_of_particles(1);
-        particles.set_texture(&albedo);
+        particles.set_textures(&particle_tex1, &particle_tex2, &particle_tex3);
 
         camera.translate(glm::vec3(0.0, 2.0, 1.0));
         // camera.rotate(30, glm::vec3(1.0, 0.0, 0.0));
@@ -97,6 +100,10 @@ class ParticleApp : public Gedeng::Application {
     Gedeng::Texture bump;
     Gedeng::Texture normal;
 
+    Gedeng::Texture particle_tex1;
+    Gedeng::Texture particle_tex2;
+    Gedeng::Texture particle_tex3;
+
     Gedeng::QuadMesh quad_mesh;
 
     Gedeng::ParticleSystem particles;