/// <summary>
/// Specifies the vertex attributes for the <see cref="ShaderProgram"/>
/// </summary>
/// <param name="attribs">The vertex attributes in order of index.</param>
/// <param name="attribNames">The names of the attributes orderd by attribute index.</param>
public void SpecifyVertexAttribs(ReadOnlySpan <VertexAttribSource> attribs, ReadOnlySpan <string> attribNames)
{
int length = 0;
for (int i = 0; i < attribs.Length; i++)
{
if (!attribs[i].IsPadding)
{
length++;
}
}
specifiedAttribs = new SpecifiedShaderAttrib[length];
int index = 0;
for (int i = 0; i < attribs.Length; i++)
{
if (!attribs[i].IsPadding)
{
specifiedAttribs[index] = new SpecifiedShaderAttrib(attribNames[index], attribs[i].AttribDescription.AttribType);
index++;
}
}
}
/// <summary>
/// Creates a <see cref="SimpleShaderProgram"/> using the current values on this
/// <see cref="SimpleShaderProgramBuilder"/>.
/// </summary>
/// <param name="graphicsDevice">The <see cref="GraphicsDevice"/> the <see cref="SimpleShaderProgram"/> will use.</param>
public SimpleShaderProgram Create(GraphicsDevice graphicsDevice)
{
const string DifferentVertexAttribIndicesError = "All specified vertex attribute indices must be different.";
VertexShaderLog = null;
FragmentShaderLog = null;
ProgramLog = null;
if (graphicsDevice == null)
{
throw new ArgumentNullException(nameof(graphicsDevice));
}
if (PositionAttributeIndex < 0)
{
throw new InvalidOperationException("A vertex attribute index for Position must always be specified.");
}
if (DiscardTransparentFragments && !float.IsFinite(TransparentFragmentThreshold))
{
throw new InvalidOperationException(nameof(TransparentFragmentThreshold) + " must be a finite value.");
}
if (LightingEnabled)
{
if (NormalAttributeIndex < 0)
{
throw new InvalidOperationException("Using lighting requires a vertex Normal attribute.");
}
if (NormalAttributeIndex == PositionAttributeIndex)
{
throw new InvalidOperationException(DifferentVertexAttribIndicesError);
}
}
if (VertexColorsEnabled)
{
if (ColorAttributeIndex < 0)
{
throw new InvalidOperationException("Using vertex colors requires a vertex Color attribute.");
}
if (ColorAttributeIndex == PositionAttributeIndex || ColorAttributeIndex == NormalAttributeIndex)
{
throw new InvalidOperationException(DifferentVertexAttribIndicesError);
}
}
if (TextureEnabled)
{
if (TexCoordsAttributeIndex < 0)
{
throw new InvalidOperationException("Using textures requires a vertex TexCoords attribute.");
}
if (TexCoordsAttributeIndex == PositionAttributeIndex || TexCoordsAttributeIndex == NormalAttributeIndex ||
TexCoordsAttributeIndex == ColorAttributeIndex)
{
throw new InvalidOperationException(DifferentVertexAttribIndicesError);
}
}
StringBuilder builder = GetStringBuilder();
ShaderProgramBuilder programBuilder = new ShaderProgramBuilder();
uint programHandle = 0;
try
{
bool useLighting = LightingEnabled;
builder.Append("#version ");
builder.Append(GLSLVersionString ?? graphicsDevice.GLMajorVersion.ToString() + graphicsDevice.GLMinorVersion.ToString() + "0 core");
builder.Append("\n\n");
if (!ExcludeWorldMatrix)
{
builder.Append("uniform mat4 World;\n");
}
builder.Append("uniform mat4 View, Projection;\n");
builder.Append("\nin vec3 vPosition;\n");
if (useLighting)
{
builder.Append("in vec3 vNormal;\n");
}
if (VertexColorsEnabled)
{
builder.Append("in vec4 vColor;\n");
}
if (TextureEnabled)
{
builder.Append("in vec2 vTexCoords;\n");
}
builder.Append('\n');
if (useLighting)
{
builder.Append("out vec3 fPosition;\nout vec3 fNormal;\n");
}
if (VertexColorsEnabled)
{
builder.Append("out vec4 fColor;\n");
}
if (TextureEnabled)
{
builder.Append("out vec2 fTexCoords;\n");
}
builder.Append("\nvoid main() {\n");
if (ExcludeWorldMatrix)
{
builder.Append("vec4 worldPos = vec4(vPosition, 1.0);\n");
}
else
{
builder.Append("vec4 worldPos = World * vec4(vPosition, 1.0);\n");
}
builder.Append("gl_Position = Projection * View * worldPos;\n\n");
if (useLighting)
{
builder.Append("fPosition = worldPos.xyz;\n");
if (ExcludeWorldMatrix)
{
builder.Append("fNormal = vNormal;\n");
}
else
{
builder.Append("fNormal = (World * vec4(vNormal, 0.0)).xyz;\n");
}
}
if (VertexColorsEnabled)
{
builder.Append("fColor = vColor;\n");
}
if (TextureEnabled)
{
builder.Append("fTexCoords = vTexCoords;\n");
}
builder.Append('}');
programBuilder.VertexShaderCode = builder.ToString();
builder.Clear();
builder.Append("#version ");
builder.Append(GLSLVersionString ?? graphicsDevice.GLMajorVersion.ToString() + graphicsDevice.GLMinorVersion.ToString() + "0 core");
builder.Append("\n\n");
builder.Append("uniform vec4 Color;\n\n");
if (TextureEnabled)
{
builder.Append("uniform sampler2D samp;\n\n");
}
if (useLighting)
{
builder.Append("uniform vec3 cameraPos;\n");
builder.Append("uniform vec3 ambientLightColor;\n");
builder.Append("uniform float reflectivity;\n");
builder.Append("uniform float specularPower;\n");
for (int i = 0; i < DirectionalLights; i++)
{
string itostring = i.ToString();
builder.Append("uniform vec3 dLightDir");
builder.Append(itostring);
builder.Append(";\nuniform vec3 dLightDiffColor");
builder.Append(itostring);
builder.Append(";\nuniform vec3 dLightSpecColor");
builder.Append(itostring);
builder.Append(";\n");
}
for (int i = 0; i < PositionalLights; i++)
{
string itostring = i.ToString();
builder.Append("uniform vec3 pLightPos");
builder.Append(itostring);
builder.Append(";\nuniform vec3 pLightDiffColor");
builder.Append(itostring);
builder.Append(";\nuniform vec3 pLightSpecColor");
builder.Append(itostring);
builder.Append(";\nuniform vec3 pAttConfig");
builder.Append(itostring);
builder.Append(";\n");
}
}
if (useLighting)
{
builder.Append("\nin vec3 fPosition;\nin vec3 fNormal;\n");
}
if (VertexColorsEnabled)
{
builder.Append("in vec4 fColor;\n");
}
if (TextureEnabled)
{
builder.Append("in vec2 fTexCoords;\n");
}
builder.Append("\nout vec4 FragColor;\n");
if (useLighting)
{
builder.Append("\nvec3 calcDirLight(in vec3 norm, in vec3 toCamVec, in vec3 lDir, in vec3 diffCol, in vec3 specCol) {\n");
builder.Append("float brightness = max(0.0, dot(norm, -lDir));\n");
builder.Append("vec3 reflectedDir = reflect(lDir, norm);\n");
builder.Append("float specFactor = max(0.0, dot(reflectedDir, toCamVec));\n");
builder.Append("float dampedFactor = pow(specFactor, specularPower);\n");
builder.Append("return brightness * diffCol + (dampedFactor * reflectivity) * specCol;\n}\n");
if (PositionalLights > 0)
{
builder.Append("\nvec3 calcPosLight(in vec3 norm, in vec3 toCamVec, in vec3 lPos, in vec3 diffCol, in vec3 specCol, in vec3 attConfig) {\n");
builder.Append("float d = distance(fPosition, lPos);\n");
builder.Append("return calcDirLight(norm, toCamVec, normalize(fPosition - lPos), diffCol, specCol) * clamp(1.0 / (attConfig.x + attConfig.y*d + attConfig.z*d*d), 0.0, 1.0);\n");
builder.Append("}\n");
}
}
builder.Append("\nvoid main() {\n");
builder.Append("vec4 finalColor = Color;\n");
if (VertexColorsEnabled)
{
builder.Append("finalColor *= fColor;\n");
}
if (TextureEnabled)
{
builder.Append("finalColor *= texture(samp, fTexCoords);\n");
}
if (DiscardTransparentFragments)
{
builder.Append("if (finalColor.A < ");
builder.Append(TransparentFragmentThreshold);
builder.Append(")\ndiscard;\n");
}
if (useLighting)
{
builder.Append("vec3 unitNormal = normalize(fNormal);\n");
builder.Append("vec3 unitToCameraVec = normalize(cameraPos - fPosition);\n\n");
builder.Append("vec3 light = ambientLightColor;\n");
for (int i = 0; i < DirectionalLights; i++)
{
string itostring = i.ToString();
builder.Append("light += calcDirLight(unitNormal, unitToCameraVec, dLightDir");
builder.Append(itostring);
builder.Append(", dLightDiffColor");
builder.Append(itostring);
builder.Append(", dLightSpecColor");
builder.Append(itostring);
builder.Append(");\n");
}
for (int i = 0; i < PositionalLights; i++)
{
string itostring = i.ToString();
builder.Append("light += calcPosLight(unitNormal, unitToCameraVec, pLightPos");
builder.Append(itostring);
builder.Append(", pLightDiffColor");
builder.Append(itostring);
builder.Append(", pLightSpecColor");
builder.Append(itostring);
builder.Append(", pAttConfig");
builder.Append(itostring);
builder.Append(");\n");
}
builder.Append("finalColor.xyz *= light;\n");
}
builder.Append("FragColor = finalColor;\n}");
programBuilder.FragmentShaderCode = builder.ToString();
int maxAttribs = Math.Max(PositionAttributeIndex, Math.Max(NormalAttributeIndex, Math.Max(ColorAttributeIndex, TexCoordsAttributeIndex)));
SpecifiedShaderAttrib[] attribs = new SpecifiedShaderAttrib[maxAttribs + 1];
for (int i = 0; i < attribs.Length; i++)
{
attribs[i] = new SpecifiedShaderAttrib(null, AttributeType.Float);
}
attribs[PositionAttributeIndex] = new SpecifiedShaderAttrib("vPosition", AttributeType.FloatVec3);
if (NormalAttributeIndex >= 0)
{
attribs[NormalAttributeIndex] = new SpecifiedShaderAttrib(useLighting ? "vNormal" : null, AttributeType.FloatVec3);
}
if (ColorAttributeIndex >= 0)
{
attribs[ColorAttributeIndex] = new SpecifiedShaderAttrib(VertexColorsEnabled ? "vColor" : null, AttributeType.FloatVec4);
}
if (TexCoordsAttributeIndex >= 0)
{
attribs[TexCoordsAttributeIndex] = new SpecifiedShaderAttrib(TextureEnabled ? "vTexCoords" : null, AttributeType.FloatVec2);
}
programBuilder.SpecifyVertexAttribs(attribs);
// TODO: Change the getLogs parameter to false
// Also, once we know the SimpleShaderProgram's code is flawless we should change this
// somehow so it doesn't raise the GraphicsDevice.ShaderCompiled event.
programHandle = programBuilder.CreateInternal(graphicsDevice, out ActiveVertexAttrib[] activeAttribs,
out bool hasVs, out bool hasGs, out bool hasFs, true);
return(new SimpleShaderProgram(graphicsDevice, programHandle, activeAttribs, hasVs, hasGs, hasFs,
VertexColorsEnabled, TextureEnabled, DirectionalLights, PositionalLights));
}
catch
{
// If anything goes wrong, we delete the program handle (since we're not returning a
// ShaderProgram so it'd get lost into oblivion otherwise) and re-throw the exception.
graphicsDevice.GL.DeleteProgram(programHandle);
throw;
}
finally
{
VertexShaderLog = programBuilder.VertexShaderLog;
FragmentShaderLog = programBuilder.FragmentShaderLog;
ProgramLog = programBuilder.ProgramLog;
builder.Clear();
ReturnStringBuilder(builder);
}
}