[Piglit] [PATCH 04/13] util: Allow non-ES2 code to draw_rect with non-fixed-function arrays

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

This will be used in future commits.

v2: Use current program state to determine whether to use fixed-function
attributes.  There are two proposals in this patch.  Hopefully reviewers
will pick one.  The first method checks whether the current program
contains an attribute named "piglit_vertex".  If it does, fixed-function
attributes are not used.  The other method check whether the current
program contains an attribute whose name starts with "gl_".  If it does,
fixed-function attributes are used.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Cc: Matt Turner <mattst88 at gmail.com>
Cc: Paul Berry <stereotype441 at gmail.com>
Cc: Eric Anholt <eric at anholt.net>
---
 tests/util/piglit-util-gl-common.c | 123 ++++++++++++++++++++++++++++---------
 1 file changed, 95 insertions(+), 28 deletions(-)

diff --git a/tests/util/piglit-util-gl-common.c b/tests/util/piglit-util-gl-common.c
index b5e87bf..ec66a65 100644
--- a/tests/util/piglit-util-gl-common.c
+++ b/tests/util/piglit-util-gl-common.c
@@ -603,42 +603,109 @@ required_gl_version_from_glsl_version(unsigned glsl_version)
 void
 piglit_draw_rect_from_arrays(const void *verts, const void *tex)
 {
-#if defined(PIGLIT_USE_OPENGL_ES1) || defined(PIGLIT_USE_OPENGL)
-	if (verts) {
-		glVertexPointer(4, GL_FLOAT, 0, verts);
-		glEnableClientState(GL_VERTEX_ARRAY);
-	}
+#if defined(PIGLIT_USE_OPENGL_ES1)
+	static const bool use_fixed_function_attributes = true;
+#elif defined(PIGLIT_USE_OPENGL_ES2) || defined(PIGLIT_USE_OPENGL_ES3)
+	static const bool use_fixed_function_attributes = false;
+#elif defined(PIGLIT_USE_OPENGL)
+	bool use_fixed_function_attributes = true;
+#else
+#error "don't know how to draw arrays"
+#endif
 
-	if (tex) {
-		glTexCoordPointer(2, GL_FLOAT, 0, tex);
-		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+#if defined(PIGLIT_USE_OPENGL)
+	if (piglit_get_gl_version() >= 20
+	    || piglit_is_extension_supported("GL_ARB_shader_objects")) {
+		GLuint prog;
+
+		glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *) &prog);
+
+#define PLAN_A
+#ifdef PLAN_A
+		/* If there is a current program and that program has an
+		 * active attribute named piglit_vertex, don't use the fixed
+		 * function inputs.
+		 */
+		use_fixed_function_attributes = prog == 0
+			|| glGetAttribLocation(prog, "piglit_vertex") == -1;
+#elif defined PLAN_B
+		if (prog != 0) {
+			GLint num_attribs;
+			int i;
+			char name[64];
+			GLint size;
+			GLenum type;
+
+			/* Assume that fixed-function attributes won't be used
+			 * until an attribute with the name "gl_*" is found.
+			 */
+			use_fixed_function_attributes = false;
+
+			glGetProgramiv(prog,
+				       GL_ACTIVE_ATTRIBUTES,
+				       &num_attribs);
+
+			for (i = 0; i < num_attribs; i++) {
+				glGetActiveAttrib(prog,
+						  i,
+						  sizeof(name),
+						  NULL,
+						  &size,
+						  &type,
+						  name);
+
+				if (strncmp("gl_", name, 3) == 0) {
+					use_fixed_function_attributes = true;
+					break;
+				}
+			}
+		}
+#endif
 	}
+#endif
 
-	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+#if defined(PIGLIT_USE_OPENGL_ES1) || defined(PIGLIT_USE_OPENGL)
+	if (use_fixed_function_attributes) {
+		if (verts) {
+			glVertexPointer(4, GL_FLOAT, 0, verts);
+			glEnableClientState(GL_VERTEX_ARRAY);
+		}
 
-	if (verts)
-		glDisableClientState(GL_VERTEX_ARRAY);
-	if (tex)
-		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
-#elif defined(PIGLIT_USE_OPENGL_ES2) ||defined(PIGLIT_USE_OPENGL_ES3)
-	if (verts) {
-		glVertexAttribPointer(PIGLIT_ATTRIB_POS, 4, GL_FLOAT, GL_FALSE, 0, verts);
-		glEnableVertexAttribArray(PIGLIT_ATTRIB_POS);
-	}
+		if (tex) {
+			glTexCoordPointer(2, GL_FLOAT, 0, tex);
+			glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+		}
+
+		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 
-	if (tex) {
-		glVertexAttribPointer(PIGLIT_ATTRIB_TEX, 2, GL_FLOAT, GL_FALSE, 0, tex);
-		glEnableVertexAttribArray(PIGLIT_ATTRIB_TEX);
+		if (verts)
+			glDisableClientState(GL_VERTEX_ARRAY);
+		if (tex)
+			glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 	}
+#endif
+#if defined(PIGLIT_USE_OPENGL_ES2) || defined(PIGLIT_USE_OPENGL_ES3) \
+	|| defined(PIGLIT_USE_OPENGL)
+	if (!use_fixed_function_attributes) {
+		if (verts) {
+			glVertexAttribPointer(PIGLIT_ATTRIB_POS, 4, GL_FLOAT,
+					      GL_FALSE, 0, verts);
+			glEnableVertexAttribArray(PIGLIT_ATTRIB_POS);
+		}
 
-	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+		if (tex) {
+			glVertexAttribPointer(PIGLIT_ATTRIB_TEX, 2, GL_FLOAT,
+					      GL_FALSE, 0, tex);
+			glEnableVertexAttribArray(PIGLIT_ATTRIB_TEX);
+		}
 
-	if (verts)
-		glDisableVertexAttribArray(PIGLIT_ATTRIB_POS);
-	if (tex)
-		glDisableVertexAttribArray(PIGLIT_ATTRIB_TEX);
-#else
-#	error "don't know how to draw arrays"
+		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+
+		if (verts)
+			glDisableVertexAttribArray(PIGLIT_ATTRIB_POS);
+		if (tex)
+			glDisableVertexAttribArray(PIGLIT_ATTRIB_TEX);
+	}
 #endif
 }
 
-- 
1.8.1.4