glprog: Wrap OpenGL program object loading

glprog provides a simple interface to loadign OpenGL program objects
and getting their uniform locations.

6 files changed, 107 insertions, 46 deletions

diff --git a/Makefile b/Makefile
index aa71c5c..5abbc46 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ CFLAGS += $(shell $(PKG_CONFIG) --cflags $(LIBS)) -std=c11 -MMD -MP
 LDFLAGS += -Wl,--as-needed
 LDLIBS += $(shell $(PKG_CONFIG) --libs $(LIBS))
 
-OBJ := gltest.o loadgl.o eprintf.o vert.o frag.o
+OBJ := gltest.o loadgl.o eprintf.o vert.o frag.o glprog.o
 DEP := $(OBJ:.o=.d)
 
 %.o: %.glsl
@@ -25,7 +25,7 @@ $(PROG): $(OBJ)
 clean:
 	$(RM) $(OBJ) $(DEP) $(PROG) $(CLEAN)
 
-loadgl.o gltest.o: loadgl.h
+loadgl.o gltest.o glprog.o: loadgl.h
 loadgl.c loadgl.h: loadgl.%: loadgl.m4 loadgl.%.in
 	m4 $^ >$@
 CLEAN += loadgl.c loadgl.h
diff --git a/gldefs.h b/gldefs.h
index cb2a87d..f1bf79f 100644
--- a/gldefs.h
+++ b/gldefs.h
@@ -57,6 +57,7 @@ enum {
 	GL_FRAGMENT_SHADER = 0x8b30,
 	GL_VERTEX_SHADER = 0x8b31,
 	GL_COMPILE_STATUS = 0x8b81,
+	GL_LINK_STATUS = 0x8b82,
 };
 
 #endif // GLDEFS_H
diff --git a/glprog.c b/glprog.c
new file mode 100644
index 0000000..84f2bab
--- /dev/null
+++ b/glprog.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2018 Tomasz Kramkowski <tk@the-tk.com>
+ * SPDX-License-Identifier: MIT
+ */
+#include <assert.h>
+
+#include "eprintf.h"
+#include "glprog.h"
+#include "loadgl.h"
+
+enum {
+	LOGSIZE = 1024,
+};
+
+static GLuint load_shader(const struct shdrdat *shdr)
+{
+	GLuint id;
+	GLint success;
+	char log[LOGSIZE];
+
+	id = gl_shdr_create(shdr->type);
+	gl_shdr_source(id, 1, &shdr->src, &shdr->len);
+	gl_shdr_compile(id);
+	gl_shdr_param(id, GL_COMPILE_STATUS, &success);
+
+	if (!success) {
+		gl_shdr_infolog(id, sizeof log, NULL, log);
+		eprintf("Failed to compile shader:\n%s", log);
+	}
+
+	return id;
+}
+
+void detach_shaders(GLuint prog)
+{
+	GLsizei count;
+	GLuint shdr;
+
+	while (gl_prog_getshdrs(prog, 1, &count, &shdr), count)
+		gl_prog_detachshdr(prog, shdr);
+}
+
+GLuint glprog_load(int nshdrs, const struct shdrdat *shdrs, int nunis, const struct unidat *unis)
+{
+	GLuint prog;
+	GLint success;
+	char log[LOGSIZE];
+
+	assert(nshdrs > 0);
+	assert(shdrs != NULL);
+	assert(nunis <= 0 || unis != NULL);
+
+	prog = gl_prog_create();
+	for (int i = 0; i < nshdrs; i++) {
+		GLuint shdr = load_shader(&shdrs[i]);
+		gl_prog_attachshdr(prog, shdr);
+		gl_shdr_del(shdr);
+	}
+	gl_prog_link(prog);
+	gl_prog_param(prog, GL_LINK_STATUS, &success);
+	if (!success) {
+		gl_prog_infolog(prog, sizeof log, NULL, log);
+		eprintf("Failed to link program:\n%s", log);
+	}
+
+	detach_shaders(prog);
+
+	for (int i = 0; i < nunis; i++)
+		*unis[i].loc = gl_uni_loc(prog, unis[i].name);
+
+	return prog;
+}
diff --git a/glprog.h b/glprog.h
new file mode 100644
index 0000000..1f540a9
--- /dev/null
+++ b/glprog.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2018 Tomasz Kramkowski <tk@the-tk.com>
+ * SPDX-License-Identifier: MIT
+ */
+#ifndef GLPROG_H
+#define GLPROG_H
+
+#include "gldefs.h"
+
+struct unidat {
+	const char *name;
+	GLint *loc;
+};
+
+struct shdrdat {
+	GLuint type;
+	const char *src;
+	GLint len;
+};
+
+GLuint glprog_load(int nshdrs, const struct shdrdat *shdrs, int nunis, const struct unidat *unis);
+
+#endif // SHADER_H
diff --git a/gltest.c b/gltest.c
index e40ee0f..cb43383 100644
--- a/gltest.c
+++ b/gltest.c
@@ -7,6 +7,7 @@
 
 #include "eprintf.h"
 #include "gldefs.h"
+#include "glprog.h"
 #include "linmath.h"
 #include "loadgl.h"
 #include "shaders.h"
@@ -14,7 +15,6 @@
 enum {
 	WIDTH = 800,
 	HEIGHT = 600,
-	LOGSIZE = 1024,
 };
 
 void fb_size_cb(GLFWwindow *win, int width, int height)
@@ -29,53 +29,12 @@ void take_input(GLFWwindow *win)
 		glfwSetWindowShouldClose(win, true);
 }
 
-GLuint load_shader(GLenum type, const char *data, GLint size)
-{
-	GLuint shdr;
-	GLint success;
-	char log[LOGSIZE];
-
-	shdr = gl_shdr_create(type);
-	gl_shdr_source(shdr, 1, &data, &size);
-	gl_shdr_compile(shdr);
-	gl_shdr_param(shdr, GL_COMPILE_STATUS, &success);
-
-	if (!success) {
-		gl_shdr_infolog(shdr, sizeof log, NULL, log);
-		eprintf("Failed to compile shader:\n%s", log);
-	}
-
-	return shdr;
-}
-
-GLuint load_prog(void)
-{
-	GLuint vert, frag, prog;
-	GLuint success;
-	char log[LOGSIZE];
-
-	vert = load_shader(GL_VERTEX_SHADER, shader_vert_data, shader_vert_size);
-	frag = load_shader(GL_FRAGMENT_SHADER, shader_frag_data, shader_frag_size);
-	prog = gl_prog_create();
-	gl_prog_attachshdr(prog, vert);
-	gl_prog_attachshdr(prog, frag);
-	gl_prog_link(prog);
-	gl_prog_param(prog, GL_COMPILE_STATUS, &success);
-	if (!success) {
-		gl_prog_infolog(prog, sizeof log, NULL, log);
-		eprintf("Failed to link program:\n%s", log);
-	}
-	gl_shdr_del(vert);
-	gl_shdr_del(frag);
-
-	return prog;
-}
-
 int main(int argc, char **argv)
 {
 	GLFWwindow *win;
 	int ret;
 	GLuint ebo, vbo, vao, prog;
+	GLint ucolor;
 	vec3 verts[] = {
 		{  0.5f,  0.5f, 0.0f },
 		{  0.5f, -0.5f, 0.0f },
@@ -121,7 +80,11 @@ int main(int argc, char **argv)
 	gl_va_define(0, 3, GL_FLOAT, GL_FALSE, sizeof *verts, 0);
 	gl_va_enable(0);
 
-	prog = load_prog();
+	prog = glprog_load(2, (struct shdrdat []){
+			{ GL_VERTEX_SHADER, shader_vert_data, shader_vert_size },
+			{ GL_FRAGMENT_SHADER, shader_frag_data, shader_frag_size },
+				},
+		1, &(struct unidat){ "ucolor", &ucolor });
 
 	gl_poly_mode(GL_FRONT_AND_BACK, GL_LINE);
 
diff --git a/loadgl.m4 b/loadgl.m4
index 8dd0316..fb9b5e4 100644
--- a/loadgl.m4
+++ b/loadgl.m4
@@ -37,6 +37,8 @@ LOAD(glGetShaderInfoLog, void, gl_shdr_infolog, GLuint shader, GLsizei size, GLs
 LOAD(glCreateProgram, GLuint, gl_prog_create, void)
 LOAD(glDeleteProgram, void, gl_prog_del, GLuint program)
 LOAD(glAttachShader, void, gl_prog_attachshdr, GLuint program, GLuint shader)
+LOAD(glDetachShader, void, gl_prog_detachshdr, GLuint program, GLuint shader)
+LOAD(glGetAttachedShaders, void, gl_prog_getshdrs, GLuint program, GLsizei max, GLsizei *count, GLuint *shaders)
 LOAD(glLinkProgram, void, gl_prog_link, GLuint program)
 LOAD(glUseProgram, void, gl_prog_use, GLuint program)
 LOAD(glGetProgramiv, void, gl_prog_param, GLuint prog, GLenum pname, GLint *params)