Gawain: improve ShaderInterface

- builtin uniforms match what Blender needs
- set input counts in struct (stupid mistake)
- look up uniforms by name
- look up builtin uniforms by enum
- check attrib/uniform locations for error

intern/gawain/gawain/shader_interface.h

@@ -20,7 +20,9 @@ typedef enum {
 	UNIFORM_PROJECTION_3D, // mat4 ProjectionMatrix
 	UNIFORM_MVP_3D,        // mat4 ModelViewProjectionMatrix
 	UNIFORM_NORMAL_3D,     // mat3 NormalMatrix
-	UNIFORM_INV_NORMAL_3D, // mat3 InverseNormalMatrix
+
+	UNIFORM_MODELVIEW_INV_3D,  // mat4 ModelViewInverseMatrix
+	UNIFORM_PROJECTION_INV_3D, // mat4 ProjectionInverseMatrix
 
 	UNIFORM_MODELVIEW_2D,  // mat3 ModelViewMatrix
 	UNIFORM_PROJECTION_2D, // mat3 ProjectionMatrix
@@ -47,3 +49,6 @@ typedef struct {
 
 ShaderInterface* ShaderInterface_create(GLint program_id);
 void ShaderInterface_discard(ShaderInterface*);
+
+const ShaderInput* ShaderInterface_uniform(const ShaderInterface*, const char* name);
+const ShaderInput* ShaderInterface_builtin_uniform(const ShaderInterface*, BuiltinUniform);

intern/gawain/src/shader_interface.c

@@ -12,6 +12,7 @@
 #include "shader_interface.h"
 #include <stdlib.h>
 #include <stddef.h>
+#include <string.h>
 
 #define DEBUG_SHADER_INTERFACE 0
 
@@ -19,8 +20,6 @@
  #include <stdio.h>
 #endif
 
-#if 0
-
 static const char* BuiltinUniform_name(BuiltinUniform u)
 	{
 	static const char* names[] =
@@ -31,7 +30,9 @@ static const char* BuiltinUniform_name(BuiltinUniform u)
 		[UNIFORM_PROJECTION_3D] = "ProjectionMatrix",
 		[UNIFORM_MVP_3D] = "ModelViewProjectionMatrix",
 		[UNIFORM_NORMAL_3D] = "NormalMatrix",
-		[UNIFORM_INV_NORMAL_3D] = "InverseNormalMatrix",
+
+		[UNIFORM_MODELVIEW_INV_3D] = "ModelViewInverseMatrix",
+		[UNIFORM_PROJECTION_INV_3D] = "ProjectionInverseMatrix",
 
 		[UNIFORM_MODELVIEW_2D] = "ModelViewMatrix",
 		[UNIFORM_PROJECTION_2D] = "ProjectionMatrix",
@@ -45,8 +46,6 @@ static const char* BuiltinUniform_name(BuiltinUniform u)
 	return names[u];
 	}
 
-#endif
-
 static bool setup_builtin_uniform(ShaderInput* input, const char* name)
 	{
 	// TODO: reject DOUBLE, IMAGE, ATOMIC_COUNTER gl_types
@@ -76,6 +75,8 @@ ShaderInterface* ShaderInterface_create(GLint program)
 
 	// allocate enough space for input counts, details for each input, and a buffer for name strings
 	ShaderInterface* shaderface = calloc(1, offsetof(ShaderInterface, inputs) + input_ct * sizeof(ShaderInput) + name_buffer_len);
+	shaderface->uniform_ct = uniform_ct;
+	shaderface->attrib_ct = attrib_ct;
 
 	char* name_buffer = (char*)shaderface + offsetof(ShaderInterface, inputs) + input_ct * sizeof(ShaderInput);
 	uint32_t name_buffer_offset = 0;
@@ -89,12 +90,19 @@ ShaderInterface* ShaderInterface_create(GLint program)
 
 		glGetActiveUniform(program, i, remaining_buffer, &name_len, &input->size, &input->gl_type, name);
 
+		input->location = glGetUniformLocation(program, name);
+
+#if TRUST_NO_ONE
+		assert(input->location != -1);
+#endif
+
 		if (setup_builtin_uniform(input, name))
 			; // reclaim space from name buffer (don't advance offset)
 		else
+			{
+			input->name = name;
 			name_buffer_offset += name_len + 1; // include NULL terminator
-
-		input->location = glGetUniformLocation(program, name);
+			}
 
 #if DEBUG_SHADER_INTERFACE
 		printf("uniform[%u] '%s' at location %d\n", i, name, input->location);
@@ -112,11 +120,15 @@ ShaderInterface* ShaderInterface_create(GLint program)
 
 		// TODO: reject DOUBLE gl_types
 
+		input->location = glGetAttribLocation(program, name);
+
+#if TRUST_NO_ONE
+		assert(input->location != -1);
+#endif
+
 		input->name = name;
 		name_buffer_offset += name_len + 1; // include NULL terminator
 
-		input->location = glGetAttribLocation(program, name);
-
 #if DEBUG_SHADER_INTERFACE
 		printf("attrib[%u] '%s' at location %d\n", i, name, input->location);
 #endif
@@ -138,3 +150,21 @@ void ShaderInterface_discard(ShaderInterface* shaderface)
 	// allocated as one chunk, so discard is simple
 	free(shaderface);
 	}
+
+const ShaderInput* ShaderInterface_uniform(const ShaderInterface* shaderface, const char* name)
+	{
+	for (uint32_t i = 0; i < shaderface->uniform_ct; ++i)
+		{
+		const ShaderInput* uniform = shaderface->inputs + i;
+
+		if (strcmp(uniform->name, name) == 0)
+			return uniform;
+		}
+	return NULL; // not found
+	}
+
+const ShaderInput* ShaderInterface_builtin_uniform(const ShaderInterface* shaderface, BuiltinUniform builtin)
+	{
+	// TODO: look up by enum, not name (fix setup_builtin_uniform first)
+	return ShaderInterface_uniform(shaderface, BuiltinUniform_name(builtin));
+	}