added distance fog

[blank.git] / src / shader.cpp

diff --git a/src/shader.cpp b/src/shader.cpp
index 99bdb74dec9995727f44470b8cddd34d85489739..eb09b10bcf2e0e1933e980e41610829452e9bc3a 100644 (file)
--- a/src/shader.cpp
+++ b/src/shader.cpp
@@ -143,9 +143,11 @@ DirectionalLighting::DirectionalLighting()
 , light_color(0.9f, 0.9f, 0.9f)
 , vp(1.0f)
 , m_handle(0)
+, mv_handle(0)
 , mvp_handle(0)
 , light_direction_handle(0)
-, light_color_handle(0) {
+, light_color_handle(0)
+, fog_density_handle(0) {
        program.LoadShader(
                GL_VERTEX_SHADER,
                "#version 330 core\n"
@@ -153,11 +155,14 @@ DirectionalLighting::DirectionalLighting()
                "layout(location = 1) in vec3 vtx_color;\n"
                "layout(location = 2) in vec3 vtx_normal;\n"
                "uniform mat4 M;\n"
+               "uniform mat4 MV;\n"
                "uniform mat4 MVP;\n"
                "out vec3 frag_color;\n"
+               "out vec3 vtx_viewspace;\n"
                "out vec3 normal;\n"
                "void main() {\n"
                        "gl_Position = MVP * vec4(vtx_position, 1);\n"
+                       "vtx_viewspace = (MV * vec4(vtx_position, 1)).xyz;\n"
                        "normal = (M * vec4(vtx_normal, 0)).xyz;\n"
                        "frag_color = vtx_color;\n"
                "}\n"
@@ -166,16 +171,23 @@ DirectionalLighting::DirectionalLighting()
                GL_FRAGMENT_SHADER,
                "#version 330 core\n"
                "in vec3 frag_color;\n"
+               "in vec3 vtx_viewspace;\n"
                "in vec3 normal;\n"
                "uniform vec3 light_direction;\n"
                "uniform vec3 light_color;\n"
+               "uniform float fog_density;\n"
                "out vec3 color;\n"
                "void main() {\n"
                        "vec3 ambient = vec3(0.1, 0.1, 0.1) * frag_color;\n"
+                       // this should be the same as the clear color, otherwise looks really weird
+                       "vec3 fog_color = vec3(0, 0, 0);\n"
+                       "float e = 2.718281828;\n"
                        "vec3 n = normalize(normal);\n"
                        "vec3 l = normalize(light_direction);\n"
                        "float cos_theta = clamp(dot(n, l), 0, 1);\n"
-                       "color = ambient + frag_color * light_color * cos_theta;\n"
+                       "vec3 reflect_color = ambient + frag_color * light_color * cos_theta;\n"
+                       "float value = pow(e, -pow(fog_density * length(vtx_viewspace), 5));"
+                       "color = mix(fog_color, reflect_color, value);\n"
                "}\n"
        );
        program.Link();
@@ -185,9 +197,11 @@ DirectionalLighting::DirectionalLighting()
        }
 
        m_handle = program.UniformLocation("M");
+       mv_handle = program.UniformLocation("MV");
        mvp_handle = program.UniformLocation("MVP");
        light_direction_handle = program.UniformLocation("light_direction");
        light_color_handle = program.UniformLocation("light_color");
+       fog_density_handle = program.UniformLocation("fog_density");
 }
 
 
@@ -201,12 +215,36 @@ void DirectionalLighting::Activate() {
 }
 
 void DirectionalLighting::SetM(const glm::mat4 &m) {
+       glm::mat4 mv(view * m);
        glm::mat4 mvp(vp * m);
        glUniformMatrix4fv(m_handle, 1, GL_FALSE, &m[0][0]);
+       glUniformMatrix4fv(mv_handle, 1, GL_FALSE, &mv[0][0]);
        glUniformMatrix4fv(mvp_handle, 1, GL_FALSE, &mvp[0][0]);
 }
 
+void DirectionalLighting::SetLightDirection(const glm::vec3 &dir) {
+       light_direction = -dir;
+       glUniform3f(light_direction_handle, light_direction.x, light_direction.y, light_direction.z);
+}
+
+void DirectionalLighting::SetFogDensity(float f) {
+       fog_density = f;
+       glUniform1f(fog_density_handle, fog_density);
+}
+
+void DirectionalLighting::SetProjection(const glm::mat4 &p) {
+       projection = p;
+       vp = p * view;
+}
+
+void DirectionalLighting::SetView(const glm::mat4 &v) {
+       view = v;
+       vp = projection * v;
+}
+
 void DirectionalLighting::SetVP(const glm::mat4 &v, const glm::mat4 &p) {
+       projection = p;
+       view = v;
        vp = p * v;
 }