more orbits and stuff

[blobs.git] / src / graphics / shader.cpp

diff --git a/src/graphics/shader.cpp b/src/graphics/shader.cpp
index b184bb98d08d6009bde2af53c30027b623f67ecc..d771d9f943385f4709108b99c2f58540cd868db2 100644 (file)
--- a/src/graphics/shader.cpp
+++ b/src/graphics/shader.cpp
@@ -1,6 +1,7 @@
 #include "PlanetSurface.hpp"
 #include "Program.hpp"
 #include "Shader.hpp"
+#include "SunSurface.hpp"
 
 #include "ArrayTexture.hpp"
 #include "../app/init.hpp"
@@ -277,5 +278,153 @@ void PlanetSurface::SetLight(const glm::vec3 &pos, const glm::vec3 &color, float
        prog.Uniform(light_strength_handle, strength);
 }
 
+
+SunSurface::SunSurface()
+: prog() {
+       prog.LoadShader(
+               GL_VERTEX_SHADER,
+               "#version 330 core\n"
+
+               "layout(location = 0) in vec3 vtx_position;\n"
+
+               "uniform mat4 M;\n"
+               "uniform mat4 MV;\n"
+               "uniform mat4 MVP;\n"
+
+               "out vec3 vtx_viewspace;\n"
+
+               "void main() {\n"
+                       "gl_Position = MVP * vec4(vtx_position, 1);\n"
+                       "vtx_viewspace = (MV * vec4(vtx_position, 1)).xyz;\n"
+               "}\n"
+       );
+       prog.LoadShader(
+               GL_FRAGMENT_SHADER,
+               "#version 330 core\n"
+
+               "in vec3 vtx_viewspace;\n"
+
+               "uniform vec3 light_color;\n"
+               "uniform float light_strength;\n"
+
+               "out vec3 color;\n"
+
+               "void main() {\n"
+                       "vec3 to_light = -vtx_viewspace;\n"
+                       "float distance = length(to_light);\n"
+                       //"vec3 light_dir = normalize(to_light);\n"
+                       "float attenuation = light_strength / (distance * distance);\n"
+                       "color = attenuation * light_color;\n"
+               "}\n"
+       );
+       prog.Link();
+       if (!prog.Linked()) {
+               prog.Log(std::cerr);
+               throw std::runtime_error("link program");
+       }
+       m_handle = prog.UniformLocation("M");
+       mv_handle = prog.UniformLocation("MV");
+       mvp_handle = prog.UniformLocation("MVP");
+       light_color_handle = prog.UniformLocation("light_color");
+       light_strength_handle = prog.UniformLocation("light_strength");
+
+       vao.Bind();
+       vao.BindAttributes();
+       vao.EnableAttribute(0);
+       vao.AttributePointer<glm::vec3>(0, false, offsetof(Attributes, position));
+       vao.ReserveAttributes(8, GL_STATIC_DRAW);
+       {
+               auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
+               attrib[0].position = glm::vec3(-1.0f, -1.0f, -1.0f);
+               attrib[1].position = glm::vec3(-1.0f, -1.0f,  1.0f);
+               attrib[2].position = glm::vec3(-1.0f,  1.0f, -1.0f);
+               attrib[3].position = glm::vec3(-1.0f,  1.0f,  1.0f);
+               attrib[4].position = glm::vec3( 1.0f, -1.0f, -1.0f);
+               attrib[5].position = glm::vec3( 1.0f, -1.0f,  1.0f);
+               attrib[6].position = glm::vec3( 1.0f,  1.0f, -1.0f);
+               attrib[7].position = glm::vec3( 1.0f,  1.0f,  1.0f);
+       }
+       vao.BindElements();
+       vao.ReserveElements(36, GL_STATIC_DRAW);
+       {
+               auto element = vao.MapElements(GL_WRITE_ONLY);
+               // -X
+               element[ 0] = 0;
+               element[ 1] = 1;
+               element[ 2] = 2;
+               element[ 3] = 2;
+               element[ 4] = 1;
+               element[ 5] = 3;
+               // -Y
+               element[ 6] = 0;
+               element[ 7] = 4;
+               element[ 8] = 1;
+               element[ 9] = 1;
+               element[10] = 4;
+               element[11] = 5;
+               // -Z
+               element[12] = 0;
+               element[13] = 2;
+               element[14] = 4;
+               element[15] = 4;
+               element[16] = 2;
+               element[17] = 6;
+               // +Z
+               element[18] = 1;
+               element[19] = 5;
+               element[20] = 3;
+               element[21] = 3;
+               element[22] = 5;
+               element[23] = 7;
+               // +Y
+               element[24] = 3;
+               element[25] = 7;
+               element[26] = 2;
+               element[27] = 2;
+               element[28] = 7;
+               element[29] = 6;
+               // +X
+               element[30] = 5;
+               element[31] = 4;
+               element[32] = 7;
+               element[33] = 7;
+               element[34] = 4;
+               element[35] = 6;
+       }
+       vao.Unbind();
+}
+
+SunSurface::~SunSurface() {
+}
+
+void SunSurface::Activate() noexcept {
+       prog.Use();
+       glEnable(GL_DEPTH_TEST);
+       glDepthFunc(GL_LESS);
+       glEnable(GL_CULL_FACE);
+       glDisable(GL_BLEND);
+}
+
+void SunSurface::SetMVP(const glm::mat4 &mm, const glm::mat4 &vv, const glm::mat4 &pp) noexcept {
+       m = mm;
+       v = vv;
+       p = pp;
+       mv = v * m;
+       mvp = p * mv;
+       prog.Uniform(m_handle, m);
+       prog.Uniform(mv_handle, mv);
+       prog.Uniform(mvp_handle, mvp);
+}
+
+void SunSurface::SetLight(const glm::vec3 &color, float strength) noexcept {
+       prog.Uniform(light_color_handle, color);
+       prog.Uniform(light_strength_handle, strength);
+}
+
+void SunSurface::Draw() const noexcept {
+       vao.Bind();
+       vao.DrawTriangles(36);
+}
+
 }
 }