mirror of
https://github.com/RetroDECK/Supermodel.git
synced 2024-11-25 15:15:40 +00:00
210 lines
7.7 KiB
GLSL
210 lines
7.7 KiB
GLSL
/**
|
|
** Supermodel
|
|
** A Sega Model 3 Arcade Emulator.
|
|
** Copyright 2011-2012 Bart Trzynadlowski, Nik Henson
|
|
**
|
|
** This file is part of Supermodel.
|
|
**
|
|
** Supermodel is free software: you can redistribute it and/or modify it under
|
|
** the terms of the GNU General Public License as published by the Free
|
|
** Software Foundation, either version 3 of the License, or (at your option)
|
|
** any later version.
|
|
**
|
|
** Supermodel is distributed in the hope that it will be useful, but WITHOUT
|
|
** ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
** FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
** more details.
|
|
**
|
|
** You should have received a copy of the GNU General Public License along
|
|
** with Supermodel. If not, see <http://www.gnu.org/licenses/>.
|
|
**/
|
|
|
|
/*
|
|
* Vertex.glsl
|
|
*
|
|
* Vertex shader for 3D rendering.
|
|
*/
|
|
|
|
#version 120
|
|
|
|
// Global uniforms
|
|
uniform mat4 modelViewMatrix; // model -> view space matrix
|
|
uniform mat4 projectionMatrix; // view space -> screen space matrix
|
|
uniform vec3 lighting[2]; // lighting state (lighting[0] = sun direction, lighting[1].x,y = diffuse, ambient intensities from 0-1.0)
|
|
uniform vec4 spotEllipse; // spotlight ellipse position: .x=X position (normalized device coordinates), .y=Y position, .z=half-width, .w=half-height)
|
|
uniform vec2 spotRange; // spotlight Z range: .x=start (viewspace coordinates), .y=limit
|
|
uniform vec3 spotColor; // spotlight RGB color
|
|
|
|
// Custom vertex attributes
|
|
attribute vec4 subTexture; // .x=texture X, .y=texture Y, .z=texture width, .w=texture height (all in texels)
|
|
attribute vec4 texParams; // .x=texture enable (if 1, else 0), .y=use transparency (if >=0), .z=U wrap mode (1=mirror, 0=repeat), .w=V wrap mode
|
|
attribute float texFormat; // T1RGB5 contour texture (if > 0)
|
|
attribute float texMap; // texture map number
|
|
attribute float transLevel; // translucence level, 0.0 (transparent) to 1.0 (opaque). if less than 1.0, replace alpha value
|
|
attribute float lightEnable; // lighting enabled (1.0) or luminous (0.0), drawn at full intensity
|
|
attribute float specular; // specular coefficient (0.0 if disabled)
|
|
attribute float shininess; // specular shininess
|
|
attribute float fogIntensity; // fog intensity (1.0, full fog effect, 0.0, no fog)
|
|
|
|
// Custom outputs to fragment shader
|
|
varying vec4 fsSubTexture;
|
|
varying vec4 fsTexParams;
|
|
varying float fsTexFormat;
|
|
varying float fsTexMap;
|
|
varying float fsTransLevel;
|
|
varying vec3 fsLightIntensity; // total light intensity for this vertex
|
|
varying float fsSpecularTerm; // specular light term (additive)
|
|
varying float fsFogFactor; // fog factor
|
|
varying float fsViewZ;
|
|
|
|
// Gets the 3x3 matrix out of a 4x4 (because mat3(mat4matrix) does not work on ATI!)
|
|
mat3 GetLinearPart( mat4 m )
|
|
{
|
|
mat3 result;
|
|
|
|
result[0][0] = m[0][0];
|
|
result[0][1] = m[0][1];
|
|
result[0][2] = m[0][2];
|
|
|
|
result[1][0] = m[1][0];
|
|
result[1][1] = m[1][1];
|
|
result[1][2] = m[1][2];
|
|
|
|
result[2][0] = m[2][0];
|
|
result[2][1] = m[2][1];
|
|
result[2][2] = m[2][2];
|
|
|
|
return result;
|
|
}
|
|
|
|
void main(void)
|
|
{
|
|
vec3 viewVertex; // vertex coordinates in view space
|
|
vec3 viewNormal; // vertex normal in view space
|
|
vec3 sunVector; // sun lighting vector (as reflecting away from vertex)
|
|
float sunFactor; // sun light projection along vertex normal (0.0 to 1.0)
|
|
vec3 halfway;
|
|
float specFactor;
|
|
|
|
// Transform vertex
|
|
gl_Position = projectionMatrix * modelViewMatrix * gl_Vertex;
|
|
viewVertex = vec3(modelViewMatrix * gl_Vertex);
|
|
|
|
/*
|
|
* Modulation
|
|
*
|
|
* Polygon color serves as material color (modulating the light intensity)
|
|
* for textured polygons. The fragment shader will ignore (overwrite) the
|
|
* the color passed to it if the fragment is textured.
|
|
*
|
|
* Untextured fragments must be set to the polygon color and the light
|
|
* intensity is initialized to 1.0 here. Alpha must be set to 1.0 because
|
|
* the fragment shader multiplies it by the polygon translucency setting.
|
|
*
|
|
* TO-DO: Does OpenGL set alpha to 1.0 by default if no alpha is specified
|
|
* for the vertex? If so, we can remove that line from here.
|
|
*/
|
|
|
|
gl_FrontColor = gl_Color; // untextured polygons will use this
|
|
gl_FrontColor.a = 1.0;
|
|
fsLightIntensity = vec3(1.0,1.0,1.0);
|
|
if (texParams.x > 0.5) // textured
|
|
fsLightIntensity *= gl_Color.rgb;
|
|
|
|
/*
|
|
* Sun Light
|
|
*
|
|
* Parallel light source and ambient lighting are only applied for non-
|
|
* luminous polygons.
|
|
*/
|
|
fsSpecularTerm = 0.0;
|
|
if (lightEnable > 0.5) // not luminous
|
|
{
|
|
// Normal -> view space
|
|
viewNormal = normalize(GetLinearPart(modelViewMatrix)*gl_Normal);
|
|
|
|
// Real3D -> OpenGL view space convention (TO-DO: do this outside of shader)
|
|
sunVector = lighting[0]*vec3(1.0,-1.0,-1.0);
|
|
|
|
// Compute diffuse factor for sunlight
|
|
sunFactor = max(dot(sunVector,viewNormal),0.0);
|
|
|
|
// Total light intensity: sum of all components
|
|
fsLightIntensity *= min(1.0,(sunFactor*lighting[1].x+lighting[1].y));
|
|
|
|
/*
|
|
* Specular Lighting
|
|
*
|
|
* The specular term is treated similarly to the "separate specular
|
|
* color" functionality of OpenGL: it is added as a highlight in the
|
|
* fragment shader. This allows even black textures to be lit.
|
|
*
|
|
* TO-DO: Ambient intensity viewport parameter is known but what about
|
|
* the intensity of the specular term? Always applied with full
|
|
* intensity here but this is unlikely to be correct.
|
|
*/
|
|
if (shininess >= 0.0)
|
|
{
|
|
// Standard specular lighting equation
|
|
if (sunFactor > 0.0)
|
|
{
|
|
vec3 V = normalize(-viewVertex);
|
|
vec3 H = normalize(sunVector+V); // halfway vector
|
|
fsSpecularTerm = specular*pow(max(dot(viewNormal,H),0.0),shininess);
|
|
|
|
// Phong formula
|
|
// vec3 R = normalize(2.0*dot(sunVector,viewNormal)*viewNormal - sunVector);
|
|
// vec3 V = normalize(-viewVertex);
|
|
// fsSpecularTerm = lighting[1].x * specular * pow(max(dot(R,V),0.0),4.);
|
|
|
|
//
|
|
// This looks decent in Scud Race attract mode. It is directionally
|
|
// correct (highlights appear in the right places under the same
|
|
// conditions as the actual game). In game play, it no longer works.
|
|
// This is loosely based on the Model 2 formula, which is:
|
|
//
|
|
// s = 2*dot(light, normal)*normal.z - light.z
|
|
//
|
|
// float dot1 = dot(sunVector, viewNormal);
|
|
// float s = dot1*viewNormal.z;
|
|
// fsSpecularTerm =specular * pow(max(s, 0.0), 2.);
|
|
//
|
|
}
|
|
|
|
/*
|
|
vec3 V = normalize(-viewVertex);
|
|
vec3 H = normalize(sunVector+V); // halfway vector
|
|
float s = max(10.0,64.0-shininess); // seems to look nice, but probably not correct
|
|
fsSpecularTerm = pow(max(dot(viewNormal,H),0.0),s);
|
|
if (sunFactor <= 0.0) fsSpecularTerm = 0.0;
|
|
*/
|
|
|
|
// Faster approximation
|
|
//float temp = max(dot(viewNormal,H),0.0);
|
|
//float s = 64.0-shininess;
|
|
//fsSpecularTerm = temp/(s-temp*s+temp);
|
|
|
|
// Phong formula
|
|
//vec3 R = normalize(2.0*dot(sunVector,viewNormal)*viewNormal - sunVector);
|
|
//vec3 V = normalize(-viewVertex);
|
|
//float s = max(2.0,64.0-shininess);
|
|
//fsSpecularTerm = pow(max(dot(R,V),0.0),s);
|
|
}
|
|
}
|
|
|
|
// Fog
|
|
float z = length(viewVertex);
|
|
fsFogFactor = fogIntensity*clamp(gl_Fog.start+z*gl_Fog.density, 0.0, 1.0);
|
|
|
|
// Pass viewspace Z coordinate (for spotlight)
|
|
fsViewZ = -viewVertex.z; // convert Z from GL->Real3D convention (want +Z to be further into screen)
|
|
|
|
// Pass remaining parameters to fragment shader
|
|
gl_TexCoord[0] = gl_MultiTexCoord0;
|
|
fsSubTexture = subTexture;
|
|
fsTexParams = texParams;
|
|
fsTransLevel = transLevel;
|
|
fsTexFormat = texFormat;
|
|
fsTexMap = texMap;
|
|
}
|