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Texture based fog table

This commit is contained in:
Flyinghead 2018-06-05 12:18:09 +02:00
parent a345fcc4c7
commit 828990b926
2 changed files with 34 additions and 81 deletions
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109
core/rend/gles/gles.cpp
View File

@ -191,7 +191,6 @@ const char* PixelPipelineShader =
uniform lowp float cp_AlphaTestValue; \n\
uniform lowp vec4 pp_ClipTest; \n\
uniform lowp vec3 sp_FOG_COL_RAM,sp_FOG_COL_VERT; \n\
uniform highp vec2 sp_LOG_FOG_COEFS; \n\
uniform highp float sp_FOG_DENSITY; \n\
uniform sampler2D tex,fog_table; \n\
/* Vertex input*/ \n\
@ -200,8 +199,12 @@ uniform sampler2D tex,fog_table; \n\
" vary " mediump vec2 vtx_uv; \n\
lowp float fog_mode2(highp float w) \n\
{ \n\
highp float fog_idx = clamp(w * sp_FOG_DENSITY, 0.0, 127.99); \n\
return clamp(sp_LOG_FOG_COEFS.y * log2(fog_idx) + sp_LOG_FOG_COEFS.x, 0.001, 1.0); //the clamp is required due to yet another bug !\n\
highp float z = clamp(w * sp_FOG_DENSITY, 1.0, 255.9999); \n\
uint i = uint(floor(log2(z))); \n\
highp float m = z * 16 / pow(2, i) - 16; \n\
float idx = floor(m) + i * 16u + 0.5; \n\
vec4 fog_coef = " TEXLOOKUP "(fog_table, vec2(idx / 128, 0.75 - (m - floor(m)) / 2)); \n\
return fog_coef.a; \n\
} \n\
void main() \n\
{ \n\
@ -324,6 +327,7 @@ gl_ctx gl;
int screen_width;
int screen_height;
GLuint fogTextureId;
#if (HOST_OS != OS_DARWIN) && !defined(TARGET_NACL32)
#if defined(GLES) && !defined(USE_SDL)
@ -637,7 +641,6 @@ struct ShaderUniforms_t
float fog_den_float;
float ps_FOG_COL_RAM[3];
float ps_FOG_COL_VERT[3];
float fog_coefs[2];
void Set(PipelineShader* s)
{
@ -658,9 +661,6 @@ struct ShaderUniforms_t
if (s->sp_FOG_COL_VERT!=-1)
glUniform3fv( s->sp_FOG_COL_VERT, 1, ps_FOG_COL_VERT);
if (s->sp_LOG_FOG_COEFS!=-1)
glUniform2fv(s->sp_LOG_FOG_COEFS,1, fog_coefs);
}
} ShaderUniforms;
@ -800,14 +800,15 @@ bool CompilePipelineShader( PipelineShader* s)
if (s->pp_FogCtrl==0 || s->pp_FogCtrl==3)
{
s->sp_FOG_COL_RAM=glGetUniformLocation(s->program, "sp_FOG_COL_RAM");
s->sp_LOG_FOG_COEFS=glGetUniformLocation(s->program, "sp_LOG_FOG_COEFS");
}
else
{
s->sp_FOG_COL_RAM=-1;
s->sp_LOG_FOG_COEFS=-1;
}
// Setup texture 1 as the fog table
gu = glGetUniformLocation(s->program, "fog_table");
if (gu != -1)
glUniform1i(gu, 1);
ShaderUniforms.Set(s);
@ -956,70 +957,32 @@ bool gles_init()
}
void tryfit(float* x,float* y)
void UpdateFogTexture(u8 *fog_table)
{
//y=B*ln(x)+A
double sylnx=0,sy=0,slnx=0,slnx2=0;
u32 cnt=0;
glActiveTexture(GL_TEXTURE1);
if (fogTextureId == 0)
{
fogTextureId = glcache.GenTexture();
glcache.BindTexture(GL_TEXTURE_2D, fogTextureId);
glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
}
else
glcache.BindTexture(GL_TEXTURE_2D, fogTextureId);
u8 temp_tex_buffer[256];
for (int i = 0; i < 128; i++)
{
int rep=1;
//discard values clipped to 0 or 1
if (i<127 && y[i]==1 && y[i+1]==1)
continue;
if (i>0 && y[i]==0 && y[i-1]==0)
continue;
//Add many samples for first and last value (fog-in, fog-out -> important)
if (i>0 && y[i]!=1 && y[i-1]==1)
rep=10000;
if (i<127 && y[i]!=0 && y[i+1]==0)
rep=10000;
for (int j=0;j<rep;j++)
{
cnt++;
const double lnx = log((double)x[i]);
sylnx += y[i] * lnx;
sy += y[i];
slnx += lnx;
slnx2 += lnx * lnx;
}
temp_tex_buffer[i] = fog_table[i * 4];
temp_tex_buffer[i + 128] = fog_table[i * 4 + 1];
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 128, 2, 0, GL_ALPHA, GL_UNSIGNED_BYTE, temp_tex_buffer);
glCheck();
double a = 0, b = 0;
if (slnx != 0)
{
b=(cnt*sylnx-sy*slnx)/(cnt*slnx2-slnx*slnx);
a=(sy-b*slnx)/(cnt);
//We use log2 and not ln on calculations //B*log(x)+A
//log2(x)=log(x)/log(2)
//log(x)=log2(x)*log(2)
//B*log(2)*log(x)+A
b*=logf(2.0);
/*
float maxdev=0;
for (int i=0;i<128;i++)
{
float diff=min(max(b*logf(x[i])/logf(2.0)+a,(double)0),(double)1)-y[i];
maxdev=max((float)fabs((float)diff),(float)maxdev);
glActiveTexture(GL_TEXTURE0);
}
printf("FOG TABLE Curve match: maxdev: %.02f cents\n",maxdev*100);
*/
}
ShaderUniforms.fog_coefs[0] = a;
ShaderUniforms.fog_coefs[1] = b;
//printf("%f\n",B*log(maxdev)/log(2.0)+A);
}
extern u16 kcode[4];
@ -1619,17 +1582,7 @@ bool RenderFrame()
if (fog_needs_update)
{
fog_needs_update = false;
//Get the coefs for the fog curve
u8* fog_table=(u8*)FOG_TABLE;
float xvals[128];
float yvals[128];
for (int i=0;i<128;i++)
{
xvals[i]=powf(2.0f,i>>4)*(1+(i&15)/16.f);
yvals[i]=fog_table[i*4+1]/255.0f;
}
tryfit(xvals,yvals);
UpdateFogTexture((u8 *)FOG_TABLE);
}
glcache.UseProgram(gl.modvol_shader.program);

2
core/rend/gles/gles.h
View File

@ -54,7 +54,7 @@ struct PipelineShader
GLuint scale,depth_scale;
GLuint pp_ClipTest,cp_AlphaTestValue;
GLuint sp_FOG_COL_RAM,sp_FOG_COL_VERT,sp_FOG_DENSITY,sp_LOG_FOG_COEFS;
GLuint sp_FOG_COL_RAM,sp_FOG_COL_VERT,sp_FOG_DENSITY;
//
u32 cp_AlphaTest; s32 pp_ClipTestMode;