Use cubemap for skyboxes

supertuxkart · Feb 26, 2014 · 61ea376 · 61ea376
1 parent 4d6b110
commit 61ea376
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Showing 5 changed files with 96 additions and 3 deletions.
diff --git a/src/graphics/irr_driver.cpp b/src/graphics/irr_driver.cpp
@@ -1171,7 +1171,9 @@ scene::ISceneNode *IrrDriver::addSkyDome(video::ITexture *texture,
 scene::ISceneNode *IrrDriver::addSkyBox(const std::vector<video::ITexture*>
                                         &texture)
 {
+    assert(texture.size() == 6);
 	SkyboxTextures = texture;
+    SkyboxCubeMap = 0;
     return m_scene_manager->addSkyBoxSceneNode(texture[0], texture[1],
                                                texture[2], texture[3],
                                                texture[4], texture[5]);
@@ -1180,6 +1182,8 @@ scene::ISceneNode *IrrDriver::addSkyBox(const std::vector<video::ITexture*>
 void IrrDriver::suppressSkyBox()
 {
 	SkyboxTextures.clear();
+    glDeleteTextures(1, &SkyboxCubeMap);
+    SkyboxCubeMap = 0;
 }
 
 // ----------------------------------------------------------------------------

diff --git a/src/graphics/irr_driver.hpp b/src/graphics/irr_driver.hpp
@@ -115,6 +115,8 @@ class IrrDriver : public IEventReceiver, public NoCopy
     core::matrix4 m_ViewMatrix, m_InvViewMatrix, m_ProjMatrix, m_InvProjMatrix, m_ProjViewMatrix, m_InvProjViewMatrix;
 
 	std::vector<video::ITexture *> SkyboxTextures;
+    GLuint SkyboxCubeMap;
+
 
     /** Flag to indicate if a resolution change is pending (which will be
      *  acted upon in the next update). None means no change, yes means
@@ -225,6 +227,7 @@ class IrrDriver : public IEventReceiver, public NoCopy
         ~IrrDriver();
     void initDevice();
     void reset();
+    void generateSkyboxCubemap();
     void renderSkybox();
 	void setPhase(STKRenderingPass);
 	STKRenderingPass getPhase() const;

diff --git a/src/graphics/render.cpp b/src/graphics/render.cpp
@@ -918,13 +918,56 @@ static void createcubevao()
 	glBufferData(GL_ELEMENT_ARRAY_BUFFER, 6 * 6 * sizeof(int), indices, GL_STATIC_DRAW);
 }
 
+#define MAX2(a, b) ((a) > (b) ? (a) : (b))
+
+void IrrDriver::generateSkyboxCubemap()
+{
+
+    glEnable(GL_TEXTURE_CUBE_MAP_SEAMLESS);
+
+    glGenTextures(1, &SkyboxCubeMap);
+
+    GLint w = 0, h = 0;
+    for (unsigned i = 0; i < 6; i++)
+    {
+        w = MAX2(w, SkyboxTextures[i]->getOriginalSize().Width);
+        h = MAX2(h, SkyboxTextures[i]->getOriginalSize().Height);
+    }
+
+    const unsigned texture_permutation[] = { 2, 3, 0, 1, 5, 4 };
+    char *rgba = new char[w * h * 4];
+    for (unsigned i = 0; i < 6; i++)
+    {
+        unsigned idx = texture_permutation[i];
+
+        video::IImage* image = getVideoDriver()->createImageFromData(
+            SkyboxTextures[idx]->getColorFormat(),
+            SkyboxTextures[idx]->getSize(),
+            SkyboxTextures[idx]->lock(),
+            false
+            );
+        SkyboxTextures[idx]->unlock();
+
+        image->copyToScaling(rgba, w, h);
+
+        glBindTexture(GL_TEXTURE_CUBE_MAP, SkyboxCubeMap);
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, w, h, 0, GL_BGRA, GL_UNSIGNED_BYTE, (GLvoid*)rgba);
+        image->drop();
+    }
+    delete[] rgba;
+    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+}
+
+
 void IrrDriver::renderSkybox()
 {
     if (SkyboxTextures.empty()) return;
 
     scene::ICameraSceneNode *camera = m_scene_manager->getActiveCamera();
 	if (!cubevao)
 		createcubevao();
+    if (!SkyboxCubeMap)
+        generateSkyboxCubemap();
 	glBindVertexArray(cubevao);
 	glDisable(GL_CULL_FACE);
 	assert(SkyboxTextures.size() == 6);
@@ -937,13 +980,17 @@ void IrrDriver::renderSkybox()
 	core::matrix4 scale;
 	scale.setScale(core::vector3df(viewDistance, viewDistance, viewDistance));
 	transform *= translate * scale;
+    core::matrix4 invtransform;
+    transform.getInverse(invtransform);
 
 	for (unsigned i = 0; i < 6; i++)
 	{
 		glActiveTexture(GL_TEXTURE0);
-		glBindTexture(GL_TEXTURE_2D, static_cast<irr::video::COpenGLTexture*>(SkyboxTextures[i])->getOpenGLTextureName());
-		glUseProgram(MeshShader::ObjectUnlitShader::Program);
-		MeshShader::ObjectUnlitShader::setUniforms(transform, 0);
+		glBindTexture(GL_TEXTURE_CUBE_MAP, SkyboxCubeMap);
+        glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glUseProgram(MeshShader::SkyboxShader::Program);
+        MeshShader::SkyboxShader::setUniforms(transform, invtransform, core::vector2df(UserConfigParams::m_width, UserConfigParams::m_height), 0);
 		glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, (GLvoid*) (6 * i * sizeof(int)));
 	}
 	glBindVertexArray(0);

diff --git a/src/graphics/shaders.cpp b/src/graphics/shaders.cpp
@@ -260,6 +260,7 @@ void Shaders::loadShaders()
     MeshShader::ShadowShader::init();
     MeshShader::RefShadowShader::init();
     MeshShader::GrassShadowShader::init();
+    MeshShader::SkyboxShader::init();
 	ParticleShader::FlipParticleRender::init();
 	ParticleShader::HeightmapSimulationShader::init();
 	ParticleShader::SimpleParticleRender::init();
@@ -1028,6 +1029,33 @@ namespace MeshShader
 		glUniform2f(uniform_dir2, dir2X, dir2Y);
 		glUniform1i(uniform_tex, TU_tex);
 	}
+
+    GLuint SkyboxShader::Program;
+    GLuint SkyboxShader::attrib_position;
+    GLuint SkyboxShader::attrib_texcoord;
+    GLuint SkyboxShader::uniform_MVP;
+    GLuint SkyboxShader::uniform_tex;
+    GLuint SkyboxShader::uniform_screen;
+    GLuint SkyboxShader::uniform_InvProjView;
+
+    void SkyboxShader::init()
+    {
+        Program = LoadProgram(file_manager->getAsset("shaders/object_pass2.vert").c_str(), file_manager->getAsset("shaders/sky.frag").c_str());
+        attrib_position = glGetAttribLocation(Program, "Position");
+        attrib_texcoord = glGetAttribLocation(Program, "Texcoord");
+        uniform_MVP = glGetUniformLocation(Program, "ModelViewProjectionMatrix");
+        uniform_InvProjView = glGetUniformLocation(Program, "InvProjView");
+        uniform_tex = glGetUniformLocation(Program, "tex");
+        uniform_screen = glGetUniformLocation(Program, "screen");
+    }
+
+    void SkyboxShader::setUniforms(const core::matrix4 &ModelViewProjectionMatrix, const core::matrix4 &InvProjView, const core::vector2df &screen, unsigned TU_tex)
+    {
+        glUniformMatrix4fv(uniform_MVP, 1, GL_FALSE, ModelViewProjectionMatrix.pointer());
+        glUniformMatrix4fv(uniform_InvProjView, 1, GL_FALSE, InvProjView.pointer());
+        glUniform1i(uniform_tex, TU_tex);
+        glUniform2f(uniform_screen, screen.X, screen.Y);
+    }
 }
 
 

diff --git a/src/graphics/shaders.hpp b/src/graphics/shaders.hpp
@@ -280,6 +280,17 @@ class DisplaceShader
 	static void setUniforms(const core::matrix4 &ModelViewProjectionMatrix, const core::matrix4 &ModelViewMatrix, float dirX, float dirY, float dir2X, float dir2Y, unsigned TU_tex);
 };
 
+class SkyboxShader
+{
+public:
+    static GLuint Program;
+    static GLuint attrib_position, attrib_texcoord;
+    static GLuint uniform_MVP, uniform_InvProjView, uniform_tex, uniform_screen;
+
+    static void init();
+    static void setUniforms(const core::matrix4 &ModelViewProjectionMatrix, const core::matrix4 &InvProjView, const core::vector2df &screen, unsigned TU_tex);
+};
+
 }
 
 namespace ParticleShader