1 /*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #ifndef GrGLSL_DEFINED
9 #define GrGLSL_DEFINED
10
11 #include "gl/GrGLInterface.h"
12 #include "GrColor.h"
13 #include "GrTypesPriv.h"
14 #include "SkString.h"
15
16 class GrGLContextInfo;
17 class GrGLShaderVar;
18
19 // Limited set of GLSL versions we build shaders for. Caller should round
20 // down the GLSL version to one of these enums.
21 enum GrGLSLGeneration {
22 /**
23 * Desktop GLSL 1.10 and ES2 shading language (based on desktop GLSL 1.20)
24 */
25 k110_GrGLSLGeneration,
26 /**
27 * Desktop GLSL 1.30
28 */
29 k130_GrGLSLGeneration,
30 /**
31 * Desktop GLSL 1.40
32 */
33 k140_GrGLSLGeneration,
34 /**
35 * Desktop GLSL 1.50
36 */
37 k150_GrGLSLGeneration,
38 };
39
40 /**
41 * Gets the most recent GLSL Generation compatible with the OpenGL context.
42 */
43 bool GrGetGLSLGeneration(const GrGLInterface* gl, GrGLSLGeneration* generation);
44
45 /**
46 * Returns a string to include at the beginning of a shader to declare the GLSL
47 * version.
48 */
49 const char* GrGetGLSLVersionDecl(const GrGLContextInfo&);
50
51 /**
52 * Converts a GrSLType to a string containing the name of the equivalent GLSL type.
53 */
GrGLSLTypeString(GrSLType t)54 static inline const char* GrGLSLTypeString(GrSLType t) {
55 switch (t) {
56 case kVoid_GrSLType:
57 return "void";
58 case kFloat_GrSLType:
59 return "float";
60 case kVec2f_GrSLType:
61 return "vec2";
62 case kVec3f_GrSLType:
63 return "vec3";
64 case kVec4f_GrSLType:
65 return "vec4";
66 case kMat33f_GrSLType:
67 return "mat3";
68 case kMat44f_GrSLType:
69 return "mat4";
70 case kSampler2D_GrSLType:
71 return "sampler2D";
72 default:
73 SkFAIL("Unknown shader var type.");
74 return ""; // suppress warning
75 }
76 }
77
78 /** A generic base-class representing a GLSL expression.
79 * The instance can be a variable name, expression or vecN(0) or vecN(1). Does simple constant
80 * folding with help of 1 and 0.
81 *
82 * Clients should not use this class, rather the specific instantiations defined
83 * later, for example GrGLSLExpr4.
84 */
85 template <typename Self>
86 class GrGLSLExpr {
87 public:
isOnes()88 bool isOnes() const { return kOnes_ExprType == fType; }
isZeros()89 bool isZeros() const { return kZeros_ExprType == fType; }
90
c_str()91 const char* c_str() const {
92 if (kZeros_ExprType == fType) {
93 return Self::ZerosStr();
94 } else if (kOnes_ExprType == fType) {
95 return Self::OnesStr();
96 }
97 SkASSERT(!fExpr.isEmpty()); // Empty expressions should not be used.
98 return fExpr.c_str();
99 }
100
101 protected:
102 /** Constructs an invalid expression.
103 * Useful only as a return value from functions that never actually return
104 * this and instances that will be assigned to later. */
GrGLSLExpr()105 GrGLSLExpr()
106 : fType(kFullExpr_ExprType) {
107 // The only constructor that is allowed to build an empty expression.
108 SkASSERT(!this->isValid());
109 }
110
111 /** Constructs an expression with all components as value v */
GrGLSLExpr(int v)112 explicit GrGLSLExpr(int v) {
113 if (v == 0) {
114 fType = kZeros_ExprType;
115 } else if (v == 1) {
116 fType = kOnes_ExprType;
117 } else {
118 fType = kFullExpr_ExprType;
119 fExpr.appendf(Self::CastIntStr(), v);
120 }
121 }
122
123 /** Constructs an expression from a string.
124 * Argument expr is a simple expression or a parenthesized expression. */
125 // TODO: make explicit once effects input Exprs.
GrGLSLExpr(const char expr[])126 GrGLSLExpr(const char expr[]) {
127 if (NULL == expr) { // TODO: remove this once effects input Exprs.
128 fType = kOnes_ExprType;
129 } else {
130 fType = kFullExpr_ExprType;
131 fExpr = expr;
132 }
133 SkASSERT(this->isValid());
134 }
135
136 /** Constructs an expression from a string.
137 * Argument expr is a simple expression or a parenthesized expression. */
138 // TODO: make explicit once effects input Exprs.
GrGLSLExpr(const SkString & expr)139 GrGLSLExpr(const SkString& expr) {
140 if (expr.isEmpty()) { // TODO: remove this once effects input Exprs.
141 fType = kOnes_ExprType;
142 } else {
143 fType = kFullExpr_ExprType;
144 fExpr = expr;
145 }
146 SkASSERT(this->isValid());
147 }
148
149 /** Constructs an expression from a string with one substitution. */
GrGLSLExpr(const char format[],const char in0[])150 GrGLSLExpr(const char format[], const char in0[])
151 : fType(kFullExpr_ExprType) {
152 fExpr.appendf(format, in0);
153 }
154
155 /** Constructs an expression from a string with two substitutions. */
GrGLSLExpr(const char format[],const char in0[],const char in1[])156 GrGLSLExpr(const char format[], const char in0[], const char in1[])
157 : fType(kFullExpr_ExprType) {
158 fExpr.appendf(format, in0, in1);
159 }
160
isValid()161 bool isValid() const {
162 return kFullExpr_ExprType != fType || !fExpr.isEmpty();
163 }
164
165 /** Returns expression casted to another type.
166 * Generic implementation that is called for non-trivial cases of casts. */
167 template <typename T>
168 static Self VectorCastImpl(const T& other);
169
170 /** Returns a GLSL multiplication: component-wise or component-by-scalar.
171 * The multiplication will be component-wise or multiply each component by a scalar.
172 *
173 * The returned expression will compute the value of:
174 * vecN(in0.x * in1.x, ...) if dim(T0) == dim(T1) (component-wise)
175 * vecN(in0.x * in1, ...) if dim(T1) == 1 (vector by scalar)
176 * vecN(in0 * in1.x, ...) if dim(T0) == 1 (scalar by vector)
177 */
178 template <typename T0, typename T1>
179 static Self Mul(T0 in0, T1 in1);
180
181 /** Returns a GLSL addition: component-wise or add a scalar to each component.
182 * Return value computes:
183 * vecN(in0.x + in1.x, ...) or vecN(in0.x + in1, ...) or vecN(in0 + in1.x, ...).
184 */
185 template <typename T0, typename T1>
186 static Self Add(T0 in0, T1 in1);
187
188 /** Returns a GLSL subtraction: component-wise or subtract compoments by a scalar.
189 * Return value computes
190 * vecN(in0.x - in1.x, ...) or vecN(in0.x - in1, ...) or vecN(in0 - in1.x, ...).
191 */
192 template <typename T0, typename T1>
193 static Self Sub(T0 in0, T1 in1);
194
195 /** Returns expression that accesses component(s) of the expression.
196 * format should be the form "%s.x" where 'x' is the component(s) to access.
197 * Caller is responsible for making sure the amount of components in the
198 * format string is equal to dim(T).
199 */
200 template <typename T>
201 T extractComponents(const char format[]) const;
202
203 private:
204 enum ExprType {
205 kZeros_ExprType,
206 kOnes_ExprType,
207 kFullExpr_ExprType,
208 };
209 ExprType fType;
210 SkString fExpr;
211 };
212
213 class GrGLSLExpr1;
214 class GrGLSLExpr4;
215
216 /** Class representing a float GLSL expression. */
217 class GrGLSLExpr1 : public GrGLSLExpr<GrGLSLExpr1> {
218 public:
GrGLSLExpr1()219 GrGLSLExpr1()
220 : INHERITED() {
221 }
GrGLSLExpr1(int v)222 explicit GrGLSLExpr1(int v)
223 : INHERITED(v) {
224 }
GrGLSLExpr1(const char * expr)225 GrGLSLExpr1(const char* expr)
226 : INHERITED(expr) {
227 }
GrGLSLExpr1(const SkString & expr)228 GrGLSLExpr1(const SkString& expr)
229 : INHERITED(expr) {
230 }
231
232 static GrGLSLExpr1 VectorCast(const GrGLSLExpr1& expr);
233
234 private:
GrGLSLExpr1(const char format[],const char in0[])235 GrGLSLExpr1(const char format[], const char in0[])
236 : INHERITED(format, in0) {
237 }
GrGLSLExpr1(const char format[],const char in0[],const char in1[])238 GrGLSLExpr1(const char format[], const char in0[], const char in1[])
239 : INHERITED(format, in0, in1) {
240 }
241
242 static const char* ZerosStr();
243 static const char* OnesStr();
244 static const char* CastStr();
245 static const char* CastIntStr();
246
247 friend GrGLSLExpr1 operator*(const GrGLSLExpr1& in0, const GrGLSLExpr1&in1);
248 friend GrGLSLExpr1 operator+(const GrGLSLExpr1& in0, const GrGLSLExpr1&in1);
249 friend GrGLSLExpr1 operator-(const GrGLSLExpr1& in0, const GrGLSLExpr1&in1);
250
251 friend class GrGLSLExpr<GrGLSLExpr1>;
252 friend class GrGLSLExpr<GrGLSLExpr4>;
253
254 typedef GrGLSLExpr<GrGLSLExpr1> INHERITED;
255 };
256
257 /** Class representing a float vector (vec4) GLSL expression. */
258 class GrGLSLExpr4 : public GrGLSLExpr<GrGLSLExpr4> {
259 public:
GrGLSLExpr4()260 GrGLSLExpr4()
261 : INHERITED() {
262 }
GrGLSLExpr4(int v)263 explicit GrGLSLExpr4(int v)
264 : INHERITED(v) {
265 }
GrGLSLExpr4(const char * expr)266 GrGLSLExpr4(const char* expr)
267 : INHERITED(expr) {
268 }
GrGLSLExpr4(const SkString & expr)269 GrGLSLExpr4(const SkString& expr)
270 : INHERITED(expr) {
271 }
272
273 typedef GrGLSLExpr1 AExpr;
274 AExpr a() const;
275
276 /** GLSL vec4 cast / constructor, eg vec4(floatv) -> vec4(floatv, floatv, floatv, floatv) */
277 static GrGLSLExpr4 VectorCast(const GrGLSLExpr1& expr);
278 static GrGLSLExpr4 VectorCast(const GrGLSLExpr4& expr);
279
280 private:
GrGLSLExpr4(const char format[],const char in0[])281 GrGLSLExpr4(const char format[], const char in0[])
282 : INHERITED(format, in0) {
283 }
GrGLSLExpr4(const char format[],const char in0[],const char in1[])284 GrGLSLExpr4(const char format[], const char in0[], const char in1[])
285 : INHERITED(format, in0, in1) {
286 }
287
288 static const char* ZerosStr();
289 static const char* OnesStr();
290 static const char* CastStr();
291 static const char* CastIntStr();
292
293 // The vector-by-scalar and scalar-by-vector binary operations.
294 friend GrGLSLExpr4 operator*(const GrGLSLExpr1& in0, const GrGLSLExpr4&in1);
295 friend GrGLSLExpr4 operator+(const GrGLSLExpr1& in0, const GrGLSLExpr4&in1);
296 friend GrGLSLExpr4 operator-(const GrGLSLExpr1& in0, const GrGLSLExpr4&in1);
297 friend GrGLSLExpr4 operator*(const GrGLSLExpr4& in0, const GrGLSLExpr1&in1);
298 friend GrGLSLExpr4 operator+(const GrGLSLExpr4& in0, const GrGLSLExpr1&in1);
299 friend GrGLSLExpr4 operator-(const GrGLSLExpr4& in0, const GrGLSLExpr1&in1);
300
301 // The vector-by-vector, i.e. component-wise, binary operations.
302 friend GrGLSLExpr4 operator*(const GrGLSLExpr4& in0, const GrGLSLExpr4&in1);
303 friend GrGLSLExpr4 operator+(const GrGLSLExpr4& in0, const GrGLSLExpr4&in1);
304 friend GrGLSLExpr4 operator-(const GrGLSLExpr4& in0, const GrGLSLExpr4&in1);
305
306 friend class GrGLSLExpr<GrGLSLExpr4>;
307
308 typedef GrGLSLExpr<GrGLSLExpr4> INHERITED;
309 };
310
311 /**
312 * Does an inplace mul, *=, of vec4VarName by mulFactor.
313 * A semicolon and newline are added after the assignment.
314 */
315 void GrGLSLMulVarBy4f(SkString* outAppend, unsigned tabCnt,
316 const char* vec4VarName, const GrGLSLExpr4& mulFactor);
317
318 #include "GrGLSL_impl.h"
319
320 #endif
321