Supermodel/Src/Graphics/New3D/R3DScrollFog.cpp
2017-07-08 10:55:14 +00:00

148 lines
3.8 KiB
C++

#include "R3DScrollFog.h"
#include "Graphics/Shader.h"
#include "Mat4.h"
namespace New3D {
static const char *vertexShaderFog = R"glsl(
uniform mat4 mvp;
void main(void)
{
gl_Position = mvp * gl_Vertex;
};
)glsl";
static const char *fragmentShaderFog = R"glsl(
uniform float fogAttenuation;
uniform float fogAmbient;
uniform vec4 fogColour;
uniform vec3 spotFogColor;
uniform vec4 spotEllipse;
// Spotlight on fog
float ellipse;
vec2 position, size;
vec3 lSpotFogColor;
// Scroll fog
float lfogAttenuation;
vec3 lFogColor;
vec4 scrollFog;
void main()
{
// Scroll fog base color
lFogColor = fogColour.rgb * fogAmbient;
// Spotlight on fog (area)
position = spotEllipse.xy;
size = spotEllipse.zw;
ellipse = length((gl_FragCoord.xy - position) / size);
ellipse = pow(ellipse, 2.0); // decay rate = square of distance from center
ellipse = 1.0 - ellipse; // invert
ellipse = max(0.0, ellipse); // clamp
// Spotlight on fog (color)
lSpotFogColor = mix(spotFogColor * ellipse * fogColour.rgb, vec3(0.0), fogAttenuation);
// Scroll fog density
scrollFog = vec4(lFogColor + lSpotFogColor, fogColour.a);
// Final Color
gl_FragColor = scrollFog;
};
)glsl";
R3DScrollFog::R3DScrollFog()
{
//default coordinates are NDC -1,1 etc
m_triangles[0].p1.Set(-1,-1, 0);
m_triangles[0].p2.Set(-1, 1, 0);
m_triangles[0].p3.Set( 1, 1, 0);
m_triangles[1].p1.Set(-1,-1, 0);
m_triangles[1].p2.Set( 1, 1, 0);
m_triangles[1].p3.Set( 1,-1, 0);
m_shaderProgram = 0;
m_vertexShader = 0;
m_fragmentShader = 0;
AllocResources();
}
R3DScrollFog::~R3DScrollFog()
{
DeallocResources();
}
void R3DScrollFog::DrawScrollFog(float rgba[4], float attenuation, float ambient, float *spotRGB, float *spotEllipse)
{
//=======
Mat4 mvp;
//=======
// yeah this would have been much easier with immediate mode and fixed function .. >_<
// some ogl states
glDepthMask (GL_FALSE); // disable z writes
glDisable (GL_DEPTH_TEST); // disable depth testing
glEnable (GL_BLEND);
glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
m_vbo.Bind (true);
glUseProgram (m_shaderProgram);
glUniform4f (m_locFogColour, rgba[0], rgba[1], rgba[2], rgba[3]);
glUniform1f (m_locFogAttenuation, attenuation);
glUniform1f (m_locFogAmbient, ambient);
glUniform3f (m_locSpotFogColor, spotRGB[0], spotRGB[1], spotRGB[2]);
glUniform4f (m_locSpotEllipse, spotEllipse[0], spotEllipse[1], spotEllipse[2], spotEllipse[3]);
glUniformMatrix4fv (m_locMVP, 1, GL_FALSE, mvp);
glEnableClientState (GL_VERTEX_ARRAY);
glVertexPointer (3, GL_FLOAT, sizeof(SFVertex), 0);
glDrawArrays (GL_TRIANGLES, 0, 6);
glDisableClientState(GL_VERTEX_ARRAY);
glUseProgram (0);
m_vbo.Bind (false);
glDisable (GL_BLEND);
glDepthMask (GL_TRUE);
}
void R3DScrollFog::AllocResources()
{
bool success = LoadShaderProgram(&m_shaderProgram, &m_vertexShader, &m_fragmentShader, std::string(), std::string(), vertexShaderFog, fragmentShaderFog);
m_locMVP = glGetUniformLocation(m_shaderProgram, "mvp");
m_locFogColour = glGetUniformLocation(m_shaderProgram, "fogColour");
m_locFogAttenuation = glGetUniformLocation(m_shaderProgram, "fogAttenuation");
m_locFogAmbient = glGetUniformLocation(m_shaderProgram, "fogAmbient");
m_locSpotFogColor = glGetUniformLocation(m_shaderProgram, "spotFogColor");
m_locSpotEllipse = glGetUniformLocation(m_shaderProgram, "spotEllipse");
m_vbo.Create(GL_ARRAY_BUFFER, GL_STATIC_DRAW, sizeof(SFTriangle) * (2), m_triangles);
}
void R3DScrollFog::DeallocResources()
{
if (m_shaderProgram) {
DestroyShaderProgram(m_shaderProgram, m_vertexShader, m_fragmentShader);
}
m_shaderProgram = 0;
m_vertexShader = 0;
m_fragmentShader = 0;
m_vbo.Destroy();
}
}