Reintegrate deferred shading

assets/shaders/forward.frag

@@ -7,8 +7,8 @@
 // By using glBindFragDataLocation(GLuint program, GLuint colorNumber, const char * name), it is not necessary to use the layout qualifier and vice-versa.
 // However, if both are used and are in conflict, the layout qualifier in the vertex shader has priority.
 layout (location = 0) out vec4 out_colour;
-layout (location = 1) out vec4 out_position;
-layout (location = 2) out vec4 out_normal;
+layout (location = 1) out vec3 out_position;
+layout (location = 2) out vec3 out_normal;
 
 // Inputs
 in io_block {
@@ -35,7 +35,7 @@ uniform vec4 u_specular_colour;
 uniform float u_gloss;
 uniform float u_displacement_scale;
 
-// Texture
+// Textures
 uniform bool u_texture_diffuse_enabled;
 uniform bool u_texture_normal_enabled;
 uniform bool u_texture_specular_enabled;
@@ -48,6 +48,10 @@ uniform sampler2D u_texture_specular;
 uniform sampler2D u_texture_gloss;
 uniform sampler2D u_texture_displacement;
 
+// Shadow
+uniform sampler2D u_texture_shadows[max_lights];
+uniform samplerCube u_cubemap_shadows[max_lights];
+
 // Light
 struct light {
     int mode_;
@@ -72,10 +76,6 @@ uniform int u_num_lights;
 uniform vec4 u_ambient_light;
 uniform light u_lights[max_lights];
 
-// Shadow
-uniform sampler2D u_texture_shadows[max_lights];
-uniform samplerCube u_cubemap_shadows[max_lights];
-
 // Includes
 vec2 parallax_occlusion(const in sampler2D _texture, const in vec2 _tex_coord, float _disp_scale, const in vec3 _frag_pos, const in mat3 _inv_tbn_matrix, const in vec3 _normal);
 
@@ -184,12 +184,12 @@ void main() {
     bool cast_shadow[max_lights];
     get_cast_shadow(normal, cast_shadow);
 
+    const vec4 ambient = get_diffuse(tex_coord) * u_ambient_light;
     const vec4 diffuse = get_diffuse(tex_coord) * get_light_diffuse(io_position, normal, cast_shadow);
     const vec4 specular = get_specular(tex_coord) * get_light_specular(io_position, normal, gloss, cast_shadow);
-    const vec4 ambient = get_diffuse(tex_coord) * u_ambient_light;
     const vec3 phong = (ambient + diffuse + specular).rgb;
 
     out_colour = vec4(phong, 1.0f);
-    out_position = vec4(io_position, 1.0f);
-    out_normal = vec4(io_normal, 1.0f);
+    out_position = io_position;
+    out_normal = io_normal;
 }

assets/shaders/forward.vert

@@ -27,18 +27,14 @@ uniform vec2 u_texture_offset;
 uniform vec2 u_texture_scale;
 
 void main() {
-    io_tex_coord = (v_tex_coord + vec3(u_texture_offset, 0.0f)) * vec3(u_texture_scale, 1.0f);
-    io_position = (u_view_matrix * v_model_matrix * vec4(v_position, 1.0f)).xyz;
-    io_normal = normalize(v_normal_matrix * v_normal);
-
-    /* This is the Gramm-Schmidt process. dot(Tangent, Normal) gives us the length of the projection of the tangent along the normal vector.
-       The product of this length by the normal itself is the component of the tangent along the normal.
-       Substract that from the tangent and we get a new vector which is perpendicular to the normal.
-       This is our new tangent. */
-    vec3 n = io_normal;
+    vec3 n = normalize(v_normal_matrix * v_normal);
     vec3 t = normalize(v_normal_matrix * v_tangent);
     t = normalize(t - dot(t, n) * n);
     vec3 b = cross(n, t);
+
+    io_tex_coord = (v_tex_coord + vec3(u_texture_offset, 0.0f)) * vec3(u_texture_scale, 1.0f);
+    io_position = (u_view_matrix * v_model_matrix * vec4(v_position, 1.0f)).xyz;
+    io_normal = n;
     io_tbn_matrix = mat3(t, b, n);
 
     gl_Position = u_projection_matrix * u_view_matrix * v_model_matrix * vec4(v_position, 1.0f);

assets/shaders/geometry.frag

@@ -1,28 +1,27 @@
 #version 460 core
 
 // IMPORTANT: All transforms in the fragment shader is in camera space, where the camera is at the origin.
-layout (location = 0) out vec4 out_position;
-layout (location = 1) out vec4 out_normal;
+layout (location = 0) out vec3 out_position;
+layout (location = 1) out vec3 out_normal;
 layout (location = 2) out vec4 out_diffuse;
 layout (location = 3) out vec4 out_specular;
 layout (location = 4) out float out_gloss;
 
 // Inputs
 in io_block {
     vec3 io_tex_coord;
-    vec3 io_position; // Vertex position in camera space.
-    vec3 io_normal; // Vertex normal in camera space.
-    mat3 io_normal_matrix;
-    mat3 io_tbn_matrix; // Converts from tangent space to camera space.
-    mat3 io_inv_tbn_matrix; // Converts from camera space to tangent space.
+    vec3 io_position;// Vertex position in camera space.
+    vec3 io_normal;// Vertex normal in camera space.
+    mat3 io_tbn_matrix;// Converts from tangent space to camera space.
 };
 
-// Uniforms
+// Material
 uniform vec4 u_diffuse_colour;
 uniform vec4 u_specular_colour;
 uniform float u_gloss;
 uniform float u_displacement_scale;
 
+// Textures
 uniform bool u_texture_diffuse_enabled;
 uniform bool u_texture_normal_enabled;
 uniform bool u_texture_specular_enabled;
@@ -35,56 +34,21 @@ uniform sampler2D u_texture_specular;
 uniform sampler2D u_texture_gloss;
 uniform sampler2D u_texture_displacement;
 
-vec2 parallax(const vec2 _tex_coord) {
-    vec3 view_direction = normalize(io_inv_tbn_matrix * io_position);
-    float depth = 1.0f - texture(u_texture_displacement, _tex_coord).r;
-    return (view_direction.xy / -view_direction.z) * depth * u_displacement_scale; // Parallax Mapping without Offset Limiting
-}
-
-vec2 parallax_occlusion(const vec2 _tex_coord) {
-    const vec2 max_uv_displacement = parallax(_tex_coord);
-    const int min_displacement_samples = 8;
-    const int max_displacement_samples = 32;
-    const float dot_product = dot(io_normal, normalize(-io_position));
-    const int num_samples = int(mix(max_displacement_samples, min_displacement_samples, dot_product));
-
-    float previous_layer_depth = 0.0f;
-    vec2 previous_uv_displacement = vec2(0.0f, 0.0f);
-    float previous_texture_depth = 0.0f;
-    for (int i = 0; i < num_samples; ++i) {
-        const float current_layer_depth = float(i)/float(num_samples);
-        const vec2 current_uv_displacement = current_layer_depth * max_uv_displacement;
-        const float current_texture_depth = 1.0f - texture(u_texture_displacement, _tex_coord + current_uv_displacement).r;
-
-        if (current_layer_depth > current_texture_depth) {
-            const float excess_depth = current_layer_depth - current_texture_depth;
-            const float lacking_depth = previous_texture_depth - previous_layer_depth;
-            return mix(previous_uv_displacement, current_uv_displacement, lacking_depth / (lacking_depth + excess_depth));
-        }
-
-        previous_layer_depth = current_layer_depth;
-        previous_uv_displacement = current_uv_displacement;
-        previous_texture_depth = current_texture_depth;
-    }
-
-    return max_uv_displacement;
-}
-
-vec2 get_tex_coord() {
-    return u_texture_displacement_enabled ? (io_tex_coord.xy + parallax_occlusion(io_tex_coord.xy)) : io_tex_coord.xy;
-}
+// Includes
+vec2 parallax_occlusion(const in sampler2D _texture, const in vec2 _tex_coord, float _disp_scale, const in vec3 _frag_pos, const in mat3 _inv_tbn_matrix, const in vec3 _normal);
 
 vec3 get_normal(const in vec2 _tex_coord) {
     if (u_texture_normal_enabled) {
-        vec3 normal = texture(u_texture_normal, _tex_coord).rgb;
-        normal *= 2.0f;
-        normal -= vec3(1.0f, 1.0f, 1.0f);
-        normal = normalize(normal);
-        return io_tbn_matrix * normal;
+        const vec3 normal = 2.0f * texture(u_texture_normal, _tex_coord).rgb - vec3(1.0f, 1.0f, 1.0f); // Convert into the [-1, 1] range.
+        return io_tbn_matrix * normal; // Convert the normal from tangent space to camera space.
     }
     return io_normal;
 }
 
+float get_gloss(const in vec2 _tex_coord) {
+    return u_texture_gloss_enabled ? texture(u_texture_gloss, _tex_coord).r * u_gloss : u_gloss;
+}
+
 vec4 get_diffuse(const in vec2 _tex_coord) {
     return u_texture_diffuse_enabled ? texture(u_texture_diffuse, _tex_coord) * u_diffuse_colour : u_diffuse_colour;
 }
@@ -93,15 +57,15 @@ vec4 get_specular(const in vec2 _tex_coord) {
     return u_texture_specular_enabled ? texture(u_texture_specular, _tex_coord) * u_specular_colour : u_specular_colour;
 }
 
-float get_gloss(const in vec2 _tex_coord) {
-    return u_texture_gloss_enabled ? texture(u_texture_gloss, _tex_coord).r * u_gloss : u_gloss;
+vec2 get_tex_coord() {
+    return u_texture_displacement_enabled ? parallax_occlusion(u_texture_displacement, io_tex_coord.xy, u_displacement_scale, io_position, io_tbn_matrix, io_normal) : io_tex_coord.xy;
 }
 
 void main() {
     const vec2 tex_coord = get_tex_coord();
 
-    out_position = vec4(io_position, 1.0f);
-    out_normal = vec4(get_normal(tex_coord), 1.0f);
+    out_position = io_position;
+    out_normal = get_normal(tex_coord);
     out_diffuse = get_diffuse(tex_coord);
     out_specular = get_specular(tex_coord);
     out_gloss = get_gloss(tex_coord);

assets/shaders/geometry.vert

@@ -17,38 +17,25 @@ out io_block {
     vec3 io_tex_coord;
     vec3 io_position; // Vertex position in camera space.
     vec3 io_normal; // Vertex normal in camera space.
-    mat3 io_normal_matrix;
     mat3 io_tbn_matrix; // Converts from tangent space to camera space.
-    mat3 io_inv_tbn_matrix; // Converts from camera space to tangent space.
 };
 
 // Uniforms
 uniform mat4 u_view_matrix;
 uniform mat4 u_projection_matrix;
-uniform mat4 u_view_projection_matrix;
 uniform vec2 u_texture_offset;
 uniform vec2 u_texture_scale;
 
 void main() {
+    vec3 n = normalize(v_normal_matrix * v_normal);
+    vec3 t = normalize(v_normal_matrix * v_tangent);
+    t = normalize(t - dot(t, n) * n);
+    vec3 b = cross(n, t);
+
     io_tex_coord = (v_tex_coord + vec3(u_texture_offset, 0.0f)) * vec3(u_texture_scale, 1.0f);
+    io_position = (u_view_matrix * v_model_matrix * vec4(v_position, 1.0f)).xyz;
+    io_normal = n;
+    io_tbn_matrix = mat3(t, b, n);
 
-    mat4 model_view_matrix = u_view_matrix * v_model_matrix;
-    io_position = (model_view_matrix * vec4(v_position, 1.0f)).xyz;
-    io_normal = normalize(v_normal_matrix * v_normal);
-    io_normal_matrix = v_normal_matrix;
-
-    // This is the Gramm-Schmidt process. dot(Tangent, Normal) gives us the length of the projection of the tangent along the normal vector.
-    // The product of this length by the normal itself is the component of the tangent along the normal.
-    // Substract that from the tangent and we get a new vector which is perpendicular to the normal.
-    // This is our new tangent (just remember to normalize it as well...).
-    vec3 tangent = normalize(v_tangent - dot(v_tangent, v_normal) * v_normal);
-    // A cross product between the tangent and the normal gives us the bitangent.
-    vec3 bitangent = normalize(cross(v_normal, tangent));
-
-    io_tbn_matrix[0] = normalize(v_normal_matrix * tangent);
-    io_tbn_matrix[1] = normalize(v_normal_matrix * bitangent);
-    io_tbn_matrix[2] = io_normal;
-    io_inv_tbn_matrix = transpose(io_tbn_matrix); // Since TBN is an orthogonal matrix, its transpose is also its inverse.
-
-    gl_Position = u_view_projection_matrix * v_model_matrix * vec4(v_position, 1.0f);
+    gl_Position = u_projection_matrix * u_view_matrix * v_model_matrix * vec4(v_position, 1.0f);
 }