arb_shader_texture_lod-texgradcube: Test explicit derivatives for cube maps

Similar to arb_shader_texture_lod-texgrad, but using cube maps instead.
Given the somewhat undefined behavior of explicit gradients with cube
maps, the main purpose of the test is really to test that those work at
all, as there doesn't seem to be any other test covering this.
That said, drivers which simply drop explicit derivatives on the floor
(like softpipe) pass this perfectly as it simply compares implicit vs.
explicit behavior (which, given the fuzzy specification, might not be
really required to be the same here, though given the chosen values, that
is the major axis derivatives being zero, it might seem like a reasonable
assumption).
I guess something which would also test that the implementation is really
using explicit derivatives instead of implicit ones would also be desirable,
but I'll leave that for now, I couldn't really come up with something.

Reviewed-by: Brian Paul <brianp@vmware.com>

2 files changed, 196 insertions, 0 deletions

diff --git a/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt b/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
index c4039394..2366fa92 100644
--- a/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
+++ b/tests/spec/arb_shader_texture_lod/execution/CMakeLists.gl.txt
@@ -10,5 +10,6 @@ link_libraries (
 )
 
 piglit_add_executable (arb_shader_texture_lod-texgrad texgrad.c)
+piglit_add_executable (arb_shader_texture_lod-texgradcube texgradcube.c)
 
 # vim: ft=cmake:
diff --git a/tests/spec/arb_shader_texture_lod/execution/texgradcube.c b/tests/spec/arb_shader_texture_lod/execution/texgradcube.c
new file mode 100644
index 00000000..90f7ddcc
--- /dev/null
+++ b/tests/spec/arb_shader_texture_lod/execution/texgradcube.c
@@ -0,0 +1,195 @@
+/*
+ * Copyright (c) 2013 VMware, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NON-INFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS AND/OR THEIR
+ * SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Roland Scheidegger <sroland@vmware.com>
+ *
+ * Based on arb_shader_texture_lod-texgrad:
+ *    Marek Olšák <maraeo@gmail.com>
+ */
+
+#include "piglit-util-gl-common.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 10;
+
+	config.window_width = 512;
+	config.window_height = 256;
+	config.window_visual = PIGLIT_GL_VISUAL_RGB | PIGLIT_GL_VISUAL_DOUBLE;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+#define TEX_WIDTH 256
+#define TEX_HEIGHT 256
+
+static const float colors[][3] = {
+	{1.0, 0.0, 0.0},
+	{0.0, 1.0, 0.0},
+	{0.0, 0.0, 1.0},
+	{1.0, 1.0, 0.0},
+	{0.0, 1.0, 1.0},
+	{1.0, 0.0, 1.0},
+	{0.5, 0.0, 0.5},
+	{1.0, 1.0, 1.0},
+};
+
+static const char *sh_tex =
+	"uniform samplerCube tex;"
+	"void main()"
+	"{"
+	"   gl_FragColor = textureCube(tex, gl_TexCoord[0].xyz);"
+	"}";
+
+static const char *sh_texgrad =
+	"#extension GL_ARB_shader_texture_lod : enable\n"
+	"uniform samplerCube tex;"
+	"void main()"
+	"{"
+	"   gl_FragColor = textureCubeGradARB(tex, gl_TexCoord[0].xyz,"
+	"                                     dFdx(gl_TexCoord[0].xyz),"
+	"                                     dFdy(gl_TexCoord[0].xyz));"
+	"}";
+
+static GLint prog_tex, prog_texgrad;
+
+void piglit_init(int argc, char **argv)
+{
+	GLuint tex, fb;
+	GLenum status;
+	int i, j, dim;
+	static GLuint fs_tex, fs_texgrad;
+
+	piglit_require_GLSL();
+	piglit_require_extension("GL_EXT_framebuffer_object");
+	piglit_require_extension("GL_ARB_shader_texture_lod");
+
+	fs_tex = piglit_compile_shader_text(GL_FRAGMENT_SHADER, sh_tex);
+	fs_texgrad = piglit_compile_shader_text(GL_FRAGMENT_SHADER, sh_texgrad);
+	prog_tex = piglit_link_simple_program(0, fs_tex);
+	prog_texgrad = piglit_link_simple_program(0, fs_texgrad);
+
+	glGenTextures(1, &tex);
+	glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
+
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
+	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+	for (j = GL_TEXTURE_CUBE_MAP_POSITIVE_X; j <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; j++) {
+		for (i = 0, dim = TEX_WIDTH; dim >0; i++, dim /= 2) {
+			glTexImage2D(j, i, GL_RGBA,
+				     dim, dim,
+				     0,
+				     GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+		}
+	}
+	assert(glGetError() == 0);
+
+	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+	glDisable(GL_TEXTURE_CUBE_MAP);
+
+	glGenFramebuffersEXT(1, &fb);
+	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
+
+	for (j = GL_TEXTURE_CUBE_MAP_POSITIVE_X; j <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; j++) {
+		for (i = 0, dim = TEX_WIDTH; dim >0; i++, dim /= 2) {
+			glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
+						  GL_COLOR_ATTACHMENT0_EXT,
+						  j,
+						  tex,
+						  i);
+
+			status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
+			if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+				fprintf(stderr, "FBO incomplete\n");
+				piglit_report_result(PIGLIT_SKIP);
+			}
+
+			glClearColor(colors[i][0],
+				     colors[i][1],
+				     colors[i][2],
+				     0.0);
+			glClear(GL_COLOR_BUFFER_BIT);
+
+			assert(glGetError() == 0);
+		}
+	}
+
+	glDeleteFramebuffersEXT(1, &fb);
+	glBindTexture(GL_TEXTURE_CUBE_MAP, tex);
+
+	glMatrixMode(GL_PROJECTION);
+	glLoadIdentity();
+	glFrustum(-0.1, 0.1, -0.1, 0.1, 0.1, 1000.0);
+
+	glMatrixMode(GL_MODELVIEW);
+	glLoadIdentity();
+	glTranslatef(-0.5, -0.5, -1.2);
+	glRotatef(68, 0, 1, 0);
+	glScalef(2000, 1, 1);
+
+	glEnable(GL_TEXTURE_CUBE_MAP);
+	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+
+	piglit_set_tolerance_for_bits(7, 7, 7, 7);
+
+	printf("Left: textureCube, Right: textureCubeGradARB\n");
+}
+
+static void draw_quad()
+{
+	glBegin(GL_QUADS);
+	glTexCoord3f(-0.5, -0.5, 1);
+	glVertex2f(0, 0);
+	glTexCoord3f(0.5, -0.5, 1);
+	glVertex2f(1, 0);
+	glTexCoord3f(0.5, 0.5, 1);
+	glVertex2f(1, 1);
+	glTexCoord3f(-0.5, 0.5, 1);
+	glVertex2f(0, 1);
+	glEnd();
+}
+
+enum piglit_result piglit_display(void)
+{
+	GLboolean pass = GL_TRUE;
+
+	glViewport(0, 0, piglit_width, piglit_height);
+	glClearColor(0.5, 0.5, 0.5, 0.5);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	glViewport(0, 0, piglit_width/2, piglit_height);
+	glUseProgram(prog_tex);
+	draw_quad();
+
+	glViewport(piglit_width/2, 0, piglit_width/2, piglit_height);
+	glUseProgram(prog_texgrad);
+	draw_quad();
+
+	if (!piglit_probe_rect_halves_equal_rgba(0, 0, piglit_width, piglit_height))
+		pass = GL_FALSE;
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}