以下是我正在使用的示例程序中的着色器：
static const char* pFS = " \n\
#version 330 \n\
\n\
const int MAX_POINT_LIGHTS = 2; \n\
const int MAX_SPOT_LIGHTS = 2; \n\
\n\
in vec4 LightSpacePos; \n\
in vec2 TexCoord0; \n\
in vec3 Normal0; \n\
in vec3 WorldPos0; \n\
in vec3 Tangent0; \n\
\n\
out vec4 FragColor; \n\
\n\
struct BaseLight \n\
{ \n\
vec3 Color; \n\
float AmbientIntensity; \n\
float DiffuseIntensity; \n\
}; \n\
\n\
struct DirectionalLight \n\
{ \n\
struct BaseLight Base; \n\
vec3 Direction; \n\
}; \n\
\n\
struct Attenuation \n\
{ \n\
float Constant; \n\
float Linear; \n\
float Exp; \n\
}; \n\
\n\
struct PointLight \n\
{ \n\
struct BaseLight Base; \n\
vec3 Position; \n\
Attenuation Atten; \n\
}; \n\
\n\
struct SpotLight \n\
{ \n\
struct PointLight Base; \n\
vec3 Direction; \n\
float Cutoff; \n\
}; \n\
\n\
uniform int gNumPointLights; \n\
uniform int gNumSpotLights; \n\
uniform DirectionalLight gDirectionalLight; \n\
uniform PointLight gPointLights[MAX_POINT_LIGHTS]; \n\
uniform SpotLight gSpotLights[MAX_SPOT_LIGHTS]; \n\
uniform sampler2D gColorMap; \n\
uniform sampler2D gShadowMap; \n\
uniform sampler2D gNormalMap; \n\
uniform vec3 gEyeWorldPos; \n\
uniform float gMatSpecularIntensity; \n\
uniform float gSpecularPower; \n\
\n\
float CalcShadowFactor(vec4 LightSpacePos) \n\
{ \n\
vec3 ProjCoords = LightSpacePos.xyz / LightSpacePos.w; \n\
vec2 UVCoords; \n\
UVCoords.x = 0.5 * ProjCoords.x + 0.5; \n\
UVCoords.y = 0.5 * ProjCoords.y + 0.5; \n\
float Depth = texture(gShadowMap, UVCoords).x; \n\
if (Depth <= (ProjCoords.z + 0.005)) \n\
return 0.5; \n\
else \n\
return 1.0; \n\
} \n\
\n\
vec4 CalcLightInternal(struct BaseLight Light, vec3 LightDirection, vec3 Normal, \n\
float ShadowFactor) \n\
{ \n\
vec4 AmbientColor = vec4(Light.Color, 1.0f) * Light.AmbientIntensity; \n\
float DiffuseFactor = dot(Normal, -LightDirection); \n\
\n\
vec4 DiffuseColor = vec4(0, 0, 0, 0); \n\
vec4 SpecularColor = vec4(0, 0, 0, 0); \n\
\n\
if (DiffuseFactor > 0) { \n\
DiffuseColor = vec4(Light.Color, 1.0f) * Light.DiffuseIntensity * DiffuseFactor; \n\
\n\
vec3 VertexToEye = normalize(gEyeWorldPos - WorldPos0); \n\
vec3 LightReflect = normalize(reflect(LightDirection, Normal)); \n\
float SpecularFactor = dot(VertexToEye, LightReflect); \n\
SpecularFactor = pow(SpecularFactor, gSpecularPower); \n\
if (SpecularFactor > 0) { \n\
SpecularColor = vec4(Light.Color, 1.0f) * \n\
gMatSpecularIntensity * SpecularFactor; \n\
} \n\
} \n\
\n\
return (AmbientColor + ShadowFactor * (DiffuseColor + SpecularColor)); \n\
} \n\
\n\
vec4 CalcDirectionalLight(vec3 Normal) \n\
{ \n\
return CalcLightInternal(gDirectionalLight.Base, gDirectionalLight.Direction, Normal, 1.0); \n\
} \n\
\n\
vec4 CalcPointLight(struct PointLight l, vec3 Normal, vec4 LightSpacePos) \n\
{ \n\
vec3 LightDirection = WorldPos0 - l.Position; \n\
float Distance = length(LightDirection); \n\
LightDirection = normalize(LightDirection); \n\
float ShadowFactor = CalcShadowFactor(LightSpacePos); \n\
\n\
vec4 Color = CalcLightInternal(l.Base, LightDirection, Normal, ShadowFactor); \n\
float Attenuation = l.Atten.Constant + \n\
l.Atten.Linear * Distance + \n\
l.Atten.Exp * Distance * Distance; \n\
\n\
return Color / Attenuation; \n\
} \n\
\n\
vec4 CalcSpotLight(struct SpotLight l, vec3 Normal, vec4 LightSpacePos) \n\
{ \n\
vec3 LightToPixel = normalize(WorldPos0 - l.Base.Position); \n\
float SpotFactor = dot(LightToPixel, l.Direction); \n\
\n\
if (SpotFactor > l.Cutoff) { \n\
vec4 Color = CalcPointLight(l.Base, Normal, LightSpacePos); \n\
return Color * (1.0 - (1.0 - SpotFactor) * 1.0/(1.0 - l.Cutoff)); \n\
} \n\
else { \n\
return vec4(0,0,0,0); \n\
} \n\
} \n\
\n\
vec3 CalcBumpedNormal() \n\
{ \n\
vec3 Normal = normalize(Normal0); \n\
vec3 Tangent = normalize(Tangent0); \n\
Tangent = normalize(Tangent - dot(Tangent, Normal) * Normal); \n\
vec3 Bitangent = cross(Tangent, Normal); \n\
vec3 BumpMapNormal = texture(gNormalMap, TexCoord0).xyz; \n\
BumpMapNormal = 2.0 * BumpMapNormal - vec3(1.0, 1.0, 1.0); \n\
vec3 NewNormal; \n\
mat3 TBN = mat3(Tangent, Bitangent, Normal); \n\
NewNormal = TBN * BumpMapNormal; \n\
NewNormal = normalize(NewNormal); \n\
return NewNormal; \n\
} \n\
\n\
void main() \n\
{ \n\
vec3 Normal = CalcBumpedNormal(); \n\
vec4 TotalLight = CalcDirectionalLight(Normal); \n\
\n\
for (int i = 0 ; i < gNumPointLights ; i++) { \n\
TotalLight += CalcPointLight(gPointLights[i], Normal, LightSpacePos); \n\
} \n\
\n\
for (int i = 0 ; i < gNumSpotLights ; i++) { \n\
TotalLight += CalcSpotLight(gSpotLights[i], Normal, LightSpacePos); \n\
} \n\
\n\
vec4 SampledColor = texture2D(gColorMap, TexCoord0.xy); \n\
FragColor = SampledColor * TotalLight; \n\
}";
GLSL抱怨：
编译FS时出错：'片段着色器无法编译，但出现以下错误：
错误：0：24：错误（＃132）语法错误：'Base'解析错误
错误：错误（＃273）1编译错误。没有代码生成'
然而，GLSL标准明确指出：
......它也是 创建一个名为variableName的该类型的变量。就像在C / C ++中一样 变量名可以省略。结构不能包含变量 采样器类型。 它们可以包含其他结构类型的变量。 结构定义命名类型。但是这种类型有限制 可以与结构类型一起使用的限定符。制服可以使用struct 类型，以及常规全局变量，局部变量和常量变量。 结构不能与任何其他存储限定符一起使用。
为什么不编译？
答案 0 :(得分：6)
struct BaseLight Base;
GLSL不是 C 。您没有像这样使用struct关键字。 BaseLight是一个类型名称，因此您只需说BaseLight Base。您在创建PointLight时正确执行此操作，因此我不知道您为什么错误地使用了BaseLight。