[Piglit] [PATCH 4/5] GL 3.2: Test that the Transform Feedback Buffer collects data before flatshading occurs

Nicholas Mack nichmack at gmail.com
Tue Aug 20 10:56:51 PDT 2013


---
 tests/spec/arb_provoking_vertex/CMakeLists.gl.txt  |   1 +
 .../arb_provoking_vertex/xfb-before-flatshading.c  | 203 +++++++++++++++++++++
 2 files changed, 204 insertions(+)
 create mode 100644 tests/spec/arb_provoking_vertex/xfb-before-flatshading.c

diff --git a/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt b/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
index a5ebff9..d70637c 100644
--- a/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
+++ b/tests/spec/arb_provoking_vertex/CMakeLists.gl.txt
@@ -12,5 +12,6 @@ link_libraries (
 piglit_add_executable (arb-provoking-vertex-control provoking-vertex-control.c)
 piglit_add_executable (arb-provoking-vertex-initial provoking-vertex-initial.c)
 piglit_add_executable (arb-quads-follow-provoking-vertex quads-follow-provoking-vertex.c)
+piglit_add_executable (arb-xfb-before-flatshading xfb-before-flatshading.c)
 
 # vim: ft=cmake:
diff --git a/tests/spec/arb_provoking_vertex/xfb-before-flatshading.c b/tests/spec/arb_provoking_vertex/xfb-before-flatshading.c
new file mode 100644
index 0000000..359ad68
--- /dev/null
+++ b/tests/spec/arb_provoking_vertex/xfb-before-flatshading.c
@@ -0,0 +1,203 @@
+/**
+ * Copyright © 2013 Intel Corporation
+ *
+ * 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
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+/**
+ * Test that transform feedback occurs before flatshading
+ *
+ * Section 2.16(Transform Feedback) of OpenGL 3.2 Core says:
+ * "In transform feedback mode, attributes of the vertices of transformed
+ * primitives processed by a vertex shader, or primitives generated by a
+ * geometry shader if one is active, are written out to one or more buffer
+ * objects. The vertices are fed back after vertex color clamping, but before
+ * flatshading and clipping."
+ *
+ */
+
+#include "piglit-util-gl-common.h"
+
+PIGLIT_GL_TEST_CONFIG_BEGIN
+
+	config.supports_gl_compat_version = 32;
+        config.supports_gl_core_version = 32;
+
+	config.window_width = 100;
+	config.window_height = 100;
+	config.window_visual = PIGLIT_GL_VISUAL_RGB | PIGLIT_GL_VISUAL_DOUBLE;
+
+PIGLIT_GL_TEST_CONFIG_END
+
+static const char *vstext = 
+	"#version 130\n"
+	"in vec3 vert1;\n"
+	"in vec3 color;\n"
+	"flat out vec3 color1;\n"
+	"out vec3 vert;\n"
+	"void main() {\n"
+	"	gl_Position = vec4(vert1, 1.);\n"
+	"	vert = vert1;\n"
+	"	color1 = color;\n"
+	"}\n";
+
+static const char *fstext = 
+	"#version 130\n"
+	"in vec3 vert;\n"
+	"flat in vec3 color1;\n"
+	"void main() {\n"
+	"	gl_FragColor = vec4(color1, 1.);\n"
+	"}\n";
+
+static GLuint vao;
+static GLuint vertBuff;
+static GLuint indexBuf;
+static GLuint vertColorBuf;
+
+static GLfloat vertices[] = {
+	-1.0, 1.0, 0.0,
+	 1.0, 1.0, 0.0,
+	 1.0,-1.0, 0.0,
+	-1.0,-1.0, 0.0
+};
+static GLsizei vertSize = sizeof(vertices);
+
+static GLfloat vertColors[] = {
+	1.0, 0.0, 0.0,
+	0.0, 1.0, 0.0,
+	0.0, 0.0, 1.0,
+	0.0, 1.0, 0.0
+};
+static GLsizei vertColorSize = sizeof(vertColors);
+
+static GLuint indices[] = {
+	0, 1, 2, 0, 2, 3
+};
+static GLsizei indSize = sizeof(indices);
+
+static GLuint xfb_buf;
+static GLuint prog;
+
+/* Only capture the color data into the transform feedback buffer */
+static const char *varyings[] = { "color1" };
+
+/* Calculate number of floats contained in the transform varyings */
+static int numVaryingFloats = ARRAY_SIZE(varyings) * ARRAY_SIZE(indices) * 3;
+
+void
+piglit_init(int argc, char **argv)
+{
+	bool pass = true;
+	GLuint vs = 0, fs = 0;
+	GLuint vertIndex;
+	GLuint vertColorIndex;
+
+	prog = glCreateProgram();
+	vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vstext);
+	fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fstext);
+	glAttachShader(prog, vs);
+	glAttachShader(prog, fs);
+	glTransformFeedbackVaryings(prog, ARRAY_SIZE(varyings), varyings,
+					GL_INTERLEAVED_ATTRIBS);
+	glLinkProgram(prog);
+	if(!piglit_link_check_status(prog)){
+		glDeleteProgram(prog);
+		piglit_report_result(PIGLIT_FAIL);
+	}
+
+	glUseProgram(prog);
+
+	glGenBuffers(1, &vertBuff);
+	glBindBuffer(GL_ARRAY_BUFFER, vertBuff);
+	glBufferData(GL_ARRAY_BUFFER, vertSize, vertices, GL_STATIC_DRAW);
+
+	glGenBuffers(1, &indexBuf);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuf);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, indSize,
+			indices, GL_STATIC_DRAW);
+
+	glGenBuffers(1, &vertColorBuf);
+	glBindBuffer(GL_ARRAY_BUFFER, vertColorBuf);
+	glBufferData(GL_ARRAY_BUFFER, vertColorSize,
+			vertColors, GL_STATIC_DRAW);
+
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+
+	vertIndex = glGetAttribLocation(prog, "vert1");
+	vertColorIndex = glGetAttribLocation(prog, "color");
+
+	glBindBuffer(GL_ARRAY_BUFFER, vertBuff);
+	glEnableVertexAttribArray(vertIndex);
+	glVertexAttribPointer(vertIndex, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	glBindBuffer(GL_ARRAY_BUFFER, vertColorBuf);
+	glEnableVertexAttribArray(vertColorIndex);
+	glVertexAttribPointer(vertColorIndex, 3, GL_FLOAT, GL_FALSE, 0, 0);
+
+	glGenBuffers(1, &xfb_buf);
+	glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, xfb_buf);
+	glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER,
+			numVaryingFloats * sizeof(float),
+			NULL, GL_STREAM_READ);
+
+	pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
+}
+
+enum piglit_result
+piglit_display(void)
+{
+	float *xBuffer;
+	int i;
+	bool pass = true;
+
+	glClearColor(0.2, 0.2, 0.2, 1.0);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+	glBindVertexArray(vao);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuf);
+
+	glBeginTransformFeedback(GL_TRIANGLES);
+	glDrawElements(GL_TRIANGLES, ARRAY_SIZE(indices),
+			GL_UNSIGNED_INT, NULL);
+	glEndTransformFeedback();
+
+	xBuffer = (float*)glMapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, GL_READ_ONLY);
+	/* Compare transform feedback color data with original color data */
+	for(i = 0; i < numVaryingFloats/3; i++) {
+		bool unchanged = true;
+		if(xBuffer[i*3+0] != vertColors[0+3*indices[i]])
+			unchanged = false;
+		if(xBuffer[i*3+1] != vertColors[1+3*indices[i]])
+			unchanged = false;
+		if(xBuffer[i*3+2] != vertColors[2+3*indices[i]])
+			unchanged = false;
+		if(!unchanged) {
+			printf("Vertex %d color was modified before being "
+				"copied into the transform buffer.\n", i);
+			pass = false;
+		}
+	}
+	glUnmapBuffer(GL_TRANSFORM_FEEDBACK_BUFFER);
+
+	piglit_present_results();
+
+	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
+}
-- 
1.8.3.1



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