4 files changed, 241 insertions, 0 deletions
diff --git a/engine/src/renderer/opengl/glsl/fragment.glsl b/engine/src/renderer/opengl/glsl/fragment.glsl
new file mode 100644
index 0000000..5bf5ff2
--- /dev/null
+++ b/engine/src/renderer/opengl/glsl/fragment.glsl
@@ -0,0 +1,73 @@
+#version 330 core
+
+#preinclude "light.glsl"
+#preinclude "vertex_data.glsl"
+
+#define MAX_LIGHT_CNT 64
+
+out vec4 FragColor;
+
+in VertexData vertex_data;
+
+uniform vec3 view_pos;
+uniform sampler2D input_texture;
+uniform Material material;
+
+uniform PointLight point_lights[MAX_LIGHT_CNT];
+uniform int point_light_cnt;
+
+uniform DirectionalLight directional_lights[MAX_LIGHT_CNT];
+uniform int directional_light_cnt;
+
+void main()
+{
+	vec3 ambient_light = calc_ambient_light(material, vertex_data.texture_coords);
+
+	vec3 directional_light_sum = vec3(0.0, 0.0, 0.0);
+
+	for (int dl_index = 0; dl_index < directional_light_cnt; dl_index++) {
+		CalculatedLight calculated_dir_light;
+
+		calc_light(
+			// Negated since we want the light to point from the light direction
+			normalize(-directional_lights[dl_index].direction),
+			directional_lights[dl_index].phong,
+			vertex_data,
+			view_pos,
+			material,
+			calculated_dir_light
+		);
+
+		directional_light_sum +=
+			calculated_dir_light.diffuse + calculated_dir_light.specular;
+	}
+
+	vec3 point_light_sum = vec3(0.0, 0.0, 0.0);
+
+	for (int pl_index = 0; pl_index < point_light_cnt; pl_index++) {
+		vec3 light_direction =
+			normalize(point_lights[pl_index].position - vertex_data.world_space_pos);
+
+		CalculatedLight calculated_point_light;
+
+		calc_light(
+			light_direction,
+			point_lights[pl_index].phong,
+			vertex_data,
+			view_pos,
+			material,
+			calculated_point_light
+		);
+
+		float attenuation =
+			calc_attenuation(point_lights[pl_index], vertex_data.world_space_pos);
+
+		calculated_point_light.diffuse *= attenuation;
+		calculated_point_light.specular *= attenuation;
+
+		point_light_sum +=
+			calculated_point_light.diffuse + calculated_point_light.specular;
+	}
+
+	FragColor = vec4((ambient_light + directional_light_sum + point_light_sum), 1.0);
+}
diff --git a/engine/src/renderer/opengl/glsl/light.glsl b/engine/src/renderer/opengl/glsl/light.glsl
new file mode 100644
index 0000000..1bc23a4
--- /dev/null
+++ b/engine/src/renderer/opengl/glsl/light.glsl
@@ -0,0 +1,133 @@
+#version 330 core
+
+#ifndef LIGHT_GLSL
+#define LIGHT_GLSL
+
+#preinclude "vertex_data.glsl"
+
+struct Material
+{
+	vec3 ambient;
+	vec3 diffuse;
+	vec3 specular;
+	sampler2D ambient_map;
+	sampler2D diffuse_map;
+	sampler2D specular_map;
+	float shininess;
+};
+
+struct LightPhong
+{
+	vec3 diffuse;
+	vec3 specular;
+};
+
+struct AttenuationProperties
+{
+	float constant;
+	float linear;
+	float quadratic;
+};
+
+struct PointLight
+{
+	LightPhong phong;
+	vec3 position;
+	AttenuationProperties attenuation_props;
+};
+
+struct DirectionalLight
+{
+	LightPhong phong;
+	vec3 direction;
+};
+
+struct CalculatedLight
+{
+	vec3 diffuse;
+	vec3 specular;
+};
+
+vec3 calc_ambient_light(in Material material, in vec2 texture_coords)
+{
+	return vec3(texture(material.ambient_map, texture_coords)) * material.ambient;
+}
+
+vec3 calc_diffuse_light(
+	in Material material,
+	in LightPhong light_phong,
+	in vec3 light_dir,
+	in vec3 norm,
+	in vec2 texture_coords
+)
+{
+	float diff = max(dot(norm, light_dir), 0.0);
+
+	return light_phong.diffuse * (
+		diff * (vec3(texture(material.diffuse_map, texture_coords)) * material.diffuse)
+	);
+}
+
+vec3 calc_specular_light(
+	in Material material,
+	in LightPhong light_phong,
+	in vec3 light_dir,
+	in vec3 norm,
+	in vec3 view_pos,
+	in vec3 frag_pos,
+	in vec2 texture_coords
+)
+{
+	vec3 view_direction = normalize(view_pos - frag_pos);
+
+	vec3 reflect_direction = reflect(-light_dir, norm);
+
+	float spec =
+		pow(max(dot(view_direction, reflect_direction), 0.0), material.shininess);
+
+	return light_phong.specular * (
+		spec * (vec3(texture(material.specular_map, texture_coords)) * material.specular)
+	);
+}
+
+float calc_attenuation(in PointLight point_light, in vec3 position)
+{
+	float light_distance = length(point_light.position - position);
+
+	return 1.0 / (point_light.attenuation_props.constant
+		+ point_light.attenuation_props.linear
+		* light_distance + point_light.attenuation_props.quadratic
+		* pow(light_distance, 2));
+}
+
+void calc_light(
+	in vec3 light_direction,
+	in LightPhong light_phong,
+	in VertexData vertex_data,
+	in vec3 view_pos,
+	in Material material,
+	out CalculatedLight calculated_light
+)
+{
+	vec3 norm = normalize(vertex_data.world_space_normal);
+
+	calculated_light.diffuse = calc_diffuse_light(
+		material,
+		light_phong,
+		light_direction,
+		norm,
+		vertex_data.texture_coords
+	);
+
+	calculated_light.specular = calc_specular_light(
+		material,
+		light_phong,
+		light_direction,
+		norm,
+		view_pos,
+		vertex_data.world_space_pos,
+		vertex_data.texture_coords
+	);
+}
+
+#endif
diff --git a/engine/src/renderer/opengl/glsl/vertex.glsl b/engine/src/renderer/opengl/glsl/vertex.glsl
new file mode 100644
index 0000000..b57caa6
--- /dev/null
+++ b/engine/src/renderer/opengl/glsl/vertex.glsl
@@ -0,0 +1,24 @@
+#version 330 core
+
+#preinclude "vertex_data.glsl"
+
+layout (location = 0) in vec3 pos;
+layout (location = 1) in vec2 texture_coords;
+layout (location = 2) in vec3 normal;
+
+out VertexData vertex_data;
+
+uniform mat4 model;
+uniform mat4 view;
+uniform mat4 projection;
+
+void main()
+{
+	gl_Position = projection * view * model * vec4(pos, 1.0);
+
+	vertex_data.world_space_pos = vec3(model * vec4(pos, 1.0));
+	vertex_data.texture_coords = texture_coords;
+
+	// TODO: Do this using CPU for performance increase
+	vertex_data.world_space_normal = mat3(transpose(inverse(model))) * normal;
+}
diff --git a/engine/src/renderer/opengl/glsl/vertex_data.glsl b/engine/src/renderer/opengl/glsl/vertex_data.glsl
new file mode 100644
index 0000000..486d445
--- /dev/null
+++ b/engine/src/renderer/opengl/glsl/vertex_data.glsl
@@ -0,0 +1,11 @@
+#ifndef VERTEX_DATA_GLSL
+#define VERTEX_DATA_GLSL
+
+struct VertexData
+{
+	vec2 texture_coords;
+	vec3 world_space_pos;
+	vec3 world_space_normal;
+};
+
+#endif