commit f39290720709d44ad166aedbf8769cfc70904c8c parent ee067d7c8b8902f466ee7650eb2bcd2d54509b2d Author: Michael Savage <mikejsavage@gmail.com> Date: Fri Jul 31 22:17:48 +0200 Re-add ground colour/lighting Diffstat:
| hm.cc | | | 181 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------------- |
| hm.png | | | 0 |
diff --git a/hm.cc b/hm.cc @@ -56,10 +56,15 @@ void print_vec3( const std::string & name, const glm::vec3 & v ) { printf( "%s: %.3f %.3f %.3f\n", name.c_str(), v.x, v.y, v.z ); } -glm::vec3 triangle_normal( const glm::vec3 & a, const glm::vec3 & b, const glm::vec3 & c ) { +// CCW winding points towards the camera +glm::vec3 triangle_normal_ccw( const glm::vec3 & a, const glm::vec3 & b, const glm::vec3 & c ) { return glm::normalize( glm::cross( b - a, c - a ) ); } +glm::vec3 triangle_perp_ccw( const glm::vec3 & a, const glm::vec3 & b, const glm::vec3 & c ) { + return glm::cross( b - a, c - a ); +} + float lerp( const float a, const float b, const float t ) { return a * ( 1 - t ) + b * t; } @@ -86,23 +91,41 @@ float bilinear_interpolation( const GLchar * const vert_src = GLSL( in vec3 position; in vec3 normal; + in float lit; - out vec3 c; + out vec3 n; + out float l; uniform mat4 vp; void main() { - c = normal; + n = normal; + l = lit; gl_Position = vp * vec4( position, 1.0 ); } ); const GLchar * frag_src = GLSL( - in vec3 c; + in vec3 n; + in float l; + out vec4 colour; + uniform vec3 sun; + void main() { - colour = vec4( c, 1.0 ); + vec3 ground; + if( n.z > 0.9 ) { + ground = vec3( 0.4, 1.0, 0.4 ); + } + else { + ground = vec3( 0.7, 0.7, 0.5 ); + } + + float d = max( 0, -dot( n, sun ) ); + float light = max( 0.2, l * d ); + + colour = vec4( ground * light, 1.0 ); } ); @@ -178,21 +201,24 @@ private: float * lit; GLuint vbo = 0; - GLuint vbo_normals = 0; + GLuint vbo_normals; + GLuint vbo_lit; GLuint vao; GLuint ebo; GLuint shader; GLint at_pos; GLint at_normal; + GLint at_lit; GLint un_vp; + GLint un_sun; public: void init( const std::string image ) { pixels = stbi_load( image.c_str(), &w, &h, nullptr, 1 ); printf( "begin lit calculations\n" ); - lit = new float[ w * h ]; + lit = new GLfloat[ w * h ]; for( int i = 0; i < w * h; i++ ) { lit[ i ] = 0; } @@ -220,6 +246,15 @@ public: } } } + + for( int y = 0; y < h; y++ ) { + for( int x = 0; x < w; x++ ) { + const int i = y * w + x; + + lit[ i ] = lit[ i ] == -1 ? 1 : 0; + } + } + printf( "end lit calculations\n" ); printf( "sending data to gpu\n" ); @@ -227,7 +262,9 @@ public: shader = compile_shader( vert_src, frag_src, "colour" ); at_pos = glGetAttribLocation( shader, "position" ); at_normal = glGetAttribLocation( shader, "normal" ); + at_lit = glGetAttribLocation( shader, "lit" ); un_vp = glGetUniformLocation( shader, "vp" ); + un_sun = glGetUniformLocation( shader, "sun" ); GLfloat * vertices = new GLfloat[ w * h * 3 ]; GLfloat * normals = new GLfloat[ w * h * 3 ]; @@ -242,7 +279,7 @@ public: vertices[ base + 1 ] = y; vertices[ base + 2 ] = height; - const glm::vec3 normal = glm::vec3( 1, 1, 0 ); + const glm::vec3 normal = point_normal( x, y ); normals[ base ] = normal.x; normals[ base + 1 ] = normal.y; @@ -274,11 +311,16 @@ public: glBindBuffer( GL_ARRAY_BUFFER, vbo_normals ); glBufferData( GL_ARRAY_BUFFER, w * h * sizeof( GLfloat ) * 3, normals, GL_STATIC_DRAW ); + glGenBuffers( 1, &vbo_lit ); + glBindBuffer( GL_ARRAY_BUFFER, vbo_lit ); + glBufferData( GL_ARRAY_BUFFER, w * h * sizeof( GLfloat ), lit, GL_STATIC_DRAW ); + glGenBuffers( 1, &ebo ); glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ebo ); glBufferData( GL_ELEMENT_ARRAY_BUFFER, ( w - 1 ) * ( h - 1 ) * sizeof( GLuint ) * 6, indices, GL_STATIC_DRAW ); delete vertices; + delete normals; delete indices; printf( "sent\n" ); @@ -288,6 +330,8 @@ public: if( vbo != 0 ) { glDeleteBuffers( 1, &ebo ); glDeleteBuffers( 1, &vbo ); + glDeleteBuffers( 1, &vbo_normals ); + glDeleteBuffers( 1, &vbo_lit ); glDeleteVertexArrays( 1, &vao ); delete lit; @@ -296,7 +340,74 @@ public: } glm::vec3 point( int x, int y ) const { - return glm::vec3( x, y, pixels[ y * w + x ] / 8.0f ); + return glm::vec3( x, y, pixels[ y * w + x ] / 4.0f ); + } + + glm::vec3 point_normal( int x, int y ) const { + glm::vec3 bent_normal = glm::vec3( 0 ); + + /* + * A vertex looks like this: + * + * +y + * \ 6 | + * \ | + * 5 \ | 1 + * \| + * ------X------ +x + * |\ + * 2 | \ 4 + * | \ + * | 3 \ + * + * We consider up to six triangles for the bent normal + */ + + if( x > 0 ) { + if( y > 0 ) { // bottom left + const glm::vec3 tri2a = point( x, y ); + const glm::vec3 tri2b = point( x - 1, y ); + const glm::vec3 tri2c = point( x, y - 1 ); + + bent_normal += triangle_normal_ccw( tri2a, tri2b, tri2c ); + } + if( y < h - 1 ) { // top left + const glm::vec3 tri5a = point( x, y ); + const glm::vec3 tri5b = point( x - 1, y + 1 ); + const glm::vec3 tri5c = point( x - 1, y ); + + const glm::vec3 tri6a = point( x, y ); + const glm::vec3 tri6b = point( x, y + 1 ); + const glm::vec3 tri6c = point( x - 1, y + 1 ); + + bent_normal += triangle_normal_ccw( tri5a, tri5b, tri5c ); + bent_normal += triangle_normal_ccw( tri6a, tri6b, tri6c ); + } + } + + if( x < w - 1 ) { + if( y > 0 ) { // bottom right + const glm::vec3 tri3a = point( x, y ); + const glm::vec3 tri3b = point( x, y - 1 ); + const glm::vec3 tri3c = point( x + 1, y - 1 ); + + const glm::vec3 tri4a = point( x, y ); + const glm::vec3 tri4b = point( x + 1, y - 1 ); + const glm::vec3 tri4c = point( x + 1, y ); + + bent_normal += triangle_normal_ccw( tri3a, tri3b, tri3c ); + bent_normal += triangle_normal_ccw( tri4a, tri4b, tri4c ); + } + if( y < h - 1 ) { // top right + const glm::vec3 tri1a = point( x, y ); + const glm::vec3 tri1b = point( x + 1, y ); + const glm::vec3 tri1c = point( x, y + 1 ); + + bent_normal += triangle_normal_ccw( tri1a, tri1b, tri1c ); + } + } + + return glm::normalize( bent_normal ); } float height( const float x, const float y ) const { @@ -313,52 +424,11 @@ public: } void render() const { - // const glm::vec3 sun = glm::normalize( glm::vec3( 1, 0, -SLOPE ) ); - // const glm::vec3 up = glm::vec3( 0, 0, 1 ); - // - // glBegin( GL_TRIANGLES ); - // for( int y = 0; y < h - 1; y++ ) { - // for( int x = 0; x < w - 1; x++ ) { - // const float noise = fabsf( stb_perlin_noise3( ( float ) x / w, ( float ) y / h, 0 ) ) / 10; - // - // const int tri1[ 3 ][ 2 ] = { { x, y }, { x, y + 1 }, { x + 1, y } }; - // const int tri2[ 3 ][ 2 ] = { { x + 1, y + 1 }, { x + 1, y }, { x, y + 1 } }; - // - // glm::vec3 points1[ 3 ]; - // glm::vec3 points2[ 3 ]; - // for( int i = 0; i < 3; i++ ) { - // points1[ i ] = point( tri1[ i ][ 0 ], tri1[ i ][ 1 ] ); - // points2[ i ] = point( tri2[ i ][ 0 ], tri2[ i ][ 1 ] ); - // } - // - // const glm::vec3 normal1 = triangle_normal( points1[ 0 ], points1[ 1 ], points1[ 2 ] ); - // const glm::vec3 normal2 = triangle_normal( points2[ 0 ], points2[ 1 ], points2[ 2 ] ); - // - // const glm::vec3 tex1 = fabsf( glm::dot( normal1, up ) ) + noise > 0.9 ? glm::vec3( 0.2, 0.6, 0.2 ) : glm::vec3( 0.5, 0.5, 0.3 ); - // const glm::vec3 tex2 = fabsf( glm::dot( normal2, up ) ) + noise > 0.9 ? glm::vec3( 0.2, 0.6, 0.2 ) : glm::vec3( 0.5, 0.5, 0.3 ); - // - // for( int i = 0; i < 3; i++ ) { - // const bool islit = lit[ tri1[ i ][ 1 ] * w + tri1[ i ][ 0 ] ] == -1; - // const float light = 0.2 + ( islit ? glm::dot( normal1, sun ) : 0 ); - // - // glColor3fv( &( tex1 * light )[ 0 ] ); - // glVertex3fv( &points1[ i ][ 0 ] ); - // } - // - // for( int i = 0; i < 3; i++ ) { - // const bool islit = lit[ tri2[ i ][ 1 ] * w + tri2[ i ][ 0 ] ] == -1; - // const float light = 0.2 + ( islit ? glm::dot( normal2, sun ) : 0 ); - // - // glColor3fv( &( tex2 * light )[ 0 ] ); - // glVertex3fv( &points2[ i ][ 0 ] ); - // } - // } - // } - // glEnd(); - glUseProgram( shader ); glBindVertexArray( vao ); + const glm::vec3 sun = glm::normalize( glm::vec3( 1, 0, -SLOPE ) ); + const glm::mat4 P = glm::perspective( glm::radians( 120.0f ), 640.0f / 480.0f, 0.1f, 10000.0f ); const glm::mat4 VP = glm::translate( glm::rotate( @@ -374,6 +444,7 @@ public: ); glUniformMatrix4fv( un_vp, 1, GL_FALSE, glm::value_ptr( VP ) ); + glUniform3fv( un_sun, 1, glm::value_ptr( sun ) ); glBindBuffer( GL_ARRAY_BUFFER, vbo ); glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ebo ); @@ -384,6 +455,10 @@ public: glEnableVertexAttribArray( at_normal ); glVertexAttribPointer( at_normal, 3, GL_FLOAT, GL_FALSE, 0, 0 ); + glBindBuffer( GL_ARRAY_BUFFER, vbo_lit ); + glEnableVertexAttribArray( at_lit ); + glVertexAttribPointer( at_lit, 1, GL_FLOAT, GL_FALSE, 0, 0 ); + glDrawElements( GL_TRIANGLES, ( w - 1 ) * ( h - 1 ) * 6, GL_UNSIGNED_INT, 0 ); } }; @@ -418,7 +493,7 @@ int main( int argc, char ** argv ) { const glm::vec3 sideways = glm::vec3( -cosf( angles.y ), sinf( angles.y ), 0 ); pos += sideways * 100.0f * dt * ( float ) lr; // pos.z = hm.height( pos.x, pos.y ) + 8; - pos.z += dz * 10.0f * dt; + pos.z += dz * 50.0f * dt; hm.render(); diff --git a/hm.png b/hm.png Binary files differ.
