basic sky box

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

diff --git a/src/graphics/shader.cpp b/src/graphics/shader.cpp
index b74d225f8d49b34a8d749fa5c127f8f9dbc381eb..f68b5b523c450f1f373ad27ef4b7343d215d3b99 100644 (file)
--- a/src/graphics/shader.cpp
+++ b/src/graphics/shader.cpp
@@ -4,9 +4,11 @@
 #include "PlanetSurface.hpp"
 #include "Program.hpp"
 #include "Shader.hpp"
+#include "SkyBox.hpp"
 #include "SunSurface.hpp"
 
 #include "ArrayTexture.hpp"
+#include "CubeMap.hpp"
 #include "Texture.hpp"
 #include "../app/init.hpp"
 
@@ -330,6 +332,131 @@ void PlanetSurface::SetNumLights(int n) noexcept {
 }
 
 
+SkyBox::SkyBox()
+: prog()
+, v(1.0f)
+, p(1.0f)
+, vp(1.0f) {
+       prog.LoadShader(
+               GL_VERTEX_SHADER,
+               "#version 330 core\n"
+
+               "layout(location = 0) in vec3 vtx_position;\n"
+
+               "uniform mat4 VP;\n"
+
+               "out vec3 vtx_viewspace;\n"
+
+               "void main() {\n"
+                       "gl_Position = VP * vec4(vtx_position, 1.0);\n"
+                       "gl_Position.z = gl_Position.w;\n"
+                       "vtx_viewspace = vtx_position;\n"
+               "}\n"
+       );
+       prog.LoadShader(
+               GL_FRAGMENT_SHADER,
+               "#version 330 core\n"
+
+               "in vec3 vtx_viewspace;\n"
+
+               "uniform samplerCube tex_sampler;\n"
+
+               "out vec3 color;\n"
+
+               "void main() {\n"
+                       "color = texture(tex_sampler, vtx_viewspace).rgb;\n"
+               "}\n"
+       );
+       prog.Link();
+       if (!prog.Linked()) {
+               prog.Log(std::cerr);
+               throw std::runtime_error("link program");
+       }
+       vp_handle = prog.UniformLocation("VP");
+       sampler_handle = prog.UniformLocation("tex_sampler");
+
+       vao.Bind();
+       vao.BindAttributes();
+       vao.EnableAttribute(0);
+       vao.AttributePointer<glm::vec3>(0, false, 0);
+       vao.ReserveAttributes(8, GL_STATIC_DRAW);
+       {
+               auto attrib = vao.MapAttributes(GL_WRITE_ONLY);
+               attrib[0] = glm::vec3(-1.0f, -1.0f, -1.0f);
+               attrib[1] = glm::vec3(-1.0f, -1.0f,  1.0f);
+               attrib[2] = glm::vec3(-1.0f,  1.0f, -1.0f);
+               attrib[3] = glm::vec3(-1.0f,  1.0f,  1.0f);
+               attrib[4] = glm::vec3( 1.0f, -1.0f, -1.0f);
+               attrib[5] = glm::vec3( 1.0f, -1.0f,  1.0f);
+               attrib[6] = glm::vec3( 1.0f,  1.0f, -1.0f);
+               attrib[7] = glm::vec3( 1.0f,  1.0f,  1.0f);
+       }
+       vao.BindElements();
+       vao.ReserveElements(14, GL_STATIC_DRAW);
+       {
+               auto element = vao.MapElements(GL_WRITE_ONLY);
+               element[ 0] = 1;
+               element[ 1] = 0;
+               element[ 2] = 3;
+               element[ 3] = 2;
+               element[ 4] = 6;
+               element[ 5] = 0;
+               element[ 6] = 4;
+               element[ 7] = 1;
+               element[ 8] = 5;
+               element[ 9] = 3;
+               element[10] = 7;
+               element[11] = 6;
+               element[12] = 5;
+               element[13] = 4;
+       }
+       vao.Unbind();
+}
+
+SkyBox::~SkyBox() {
+}
+
+void SkyBox::Activate() noexcept {
+       prog.Use();
+       glEnable(GL_DEPTH_TEST);
+       glDepthFunc(GL_LEQUAL);
+       glDisable(GL_CULL_FACE);
+       glDisable(GL_BLEND);
+}
+
+void SkyBox::SetV(const glm::mat4 &vv) noexcept {
+       v = vv;
+       v[0].w = 0.0f;
+       v[1].w = 0.0f;
+       v[2].w = 0.0f;
+       v[3] = glm::vec4(0.0f, 0.0f, 0.0f, 1.0f);
+       vp = p * v;
+       prog.Uniform(vp_handle, vp);
+}
+
+void SkyBox::SetP(const glm::mat4 &pp) noexcept {
+       p = pp;
+       vp = p * v;
+       prog.Uniform(vp_handle, vp);
+}
+
+void SkyBox::SetVP(const glm::mat4 &vv, const glm::mat4 &pp) noexcept {
+       p = pp;
+       SetV(vv);
+}
+
+void SkyBox::SetTexture(CubeMap &cm) noexcept {
+       glActiveTexture(GL_TEXTURE0);
+       cm.Bind();
+       prog.Uniform(sampler_handle, GLint(0));
+}
+
+void SkyBox::Draw() const noexcept {
+       vao.Bind();
+       vao.DrawTriangleStrip(14);
+}
+
+
 SunSurface::SunSurface()
 : prog() {
        prog.LoadShader(